J2me bluetooth

J2ME Bluetooth
Programming

Master's Thesis

André N. Klingsheim
Department of Informatics
University of Bergen

30th June 2004

The NoWires Research Group

http://www.nowires.org
http://wireless.klings.org

Preface
This Master's thesis gives insights into the technologies needed to develop Java
Bluetooth applications for mobile devices. Bluetooth, Java 2 Micro Edition (J2ME),
and Java APIs for Bluetooth Wireless Technology (JABWT) are discussed. The
necessary infrastructure for developing Java Bluetooth applications are also
described. Descriptions of how different Bluetooth actions like inquiry and service
discovery are done with the Java API are provided. Code samples are included as
well, highlighting the functionality available in JABWT.

Books on JABWT programming became available during the writing of this thesis.
Simple functionality is often explained in a far too complex way in these books,
making it hard for developers to get started with Java Bluetooth programming. This
thesis aims to give a clean and basic introduction to the simple parts of JABWT
before the more complex functionality is explained. Also, a broad view of the
technology is given, enabling developers to see where JABWT has its place among
other technologies. Different software platforms, development tools, and Java
Bluetooth enabled devices are discussed.

I

Acknowledgments
I would first of all like to thank Professor Kjell Jørgen Hole for giving me the
opportunity to work with the Java and Bluetooth technologies. He has been highly
available and highly supportive throughout the whole process of writing this thesis. I
also thank my common-law spouse Eli for her patience, understanding and
encouragement. I would like to thank my parents, Tor and Barbro, for invaluable
support through the years. Even though they do not know much about Java or
Bluetooth, they still have shown great interest in my work. My fellow students must
not be forgotten. It has been a privilege to make their acquaintance, I will surely miss
the monthly gatherings at our favorite uncle Lauritz.

III

Table of Contents
Chapter 1 Introduction..........................................................................................1
1.1 Structure of thesis.................................................................................2
Chapter 2 Bluetooth...............................................................................................5
2.1 Bluetooth architecture...........................................................................6
2.2 Piconet and scatternet............................................................................8
2.3 Bluetooth links....................................................................................11
2.4 Device discovery (inquiry) and service discovery..............................12
2.5 Bluetooth services...............................................................................13
2.6 Bluetooth profiles................................................................................15
2.7 Bluetooth qualification........................................................................16
2.8 Bluetooth security...............................................................................17
2.8.1 Security modes...........................................................................17
2.8.2 Pairing and bonding (authentication).........................................18
2.8.3 Encryption..................................................................................18
2.8.4 Authorization.............................................................................19
2.8.5 Security manager.......................................................................19
2.8.6 Security mode 2.........................................................................20
Chapter 3 Java 2 Micro Edition (J2ME)............................................................21
3.1 Configurations and profiles.................................................................22
3.2 Connected Limited Device Configuration (CLDC)............................22
3.2.1 Generic Connection Framework (GCF).....................................23
3.2.2 CLDC versions and requirements..............................................23
3.2.3 CLDC security...........................................................................24
3.3 Mobile Information Device Profile (MIDP).......................................25
3.3.1 MIDP version 1..........................................................................26
3.3.2 MIDP version 2..........................................................................27
3.4 MIDlets...............................................................................................29
3.4.1 OEM-specific applications.........................................................30
3.4.2 MIDlet suites..............................................................................30
3.4.3 MIDlet deployment....................................................................31
3.5 Java APIs for Bluetooth Wireless Technology (JABWT)..................32
3.5.1 Security......................................................................................33
Chapter 4 Infrastructure......................................................................................35
4.1 Linux workstation...............................................................................35
4.2 Sun wireless toolkits...........................................................................35
4.3 Rococo Impronto simulator.................................................................36
4.4 Smartphones........................................................................................37
4.4.1 Nokia 6600.................................................................................37
4.4.2 Sony Ericsson P900...................................................................37
4.5 Web server, www.klings.org/nowires/...............................................38
4.6 IDEs....................................................................................................39
Chapter 5 J2ME and JABWT programming.....................................................41
5.1 Structure of Bluetooth MIDlet............................................................41
5.2 Device discovery (Inquiry).................................................................43

V

5.3 Service search.....................................................................................48
5.4 RFCOMM links with JABWT............................................................52
5.4.1 RFCOMM server.......................................................................53
5.4.2 RFCOMM client........................................................................54
5.4.3 RFCOMM connection parameters.............................................55
5.5 Service records and JABWT...............................................................57
5.5.1 Retrieving information from service records with JABWT.....57
5.5.2 Manipulating service records with JABWT..............................59
5.6 Pitfalls.................................................................................................62
5.6.1 RFCOMM flow control.............................................................62
5.6.2 RFCOMM EOF.........................................................................63
5.6.3 Removal of service records........................................................63
5.6.4 Populating service records.........................................................63
5.6.5 Inquiry with P900......................................................................64
5.6.6 ServiceRecordHandle format.....................................................64
Chapter 6 Sample applications............................................................................65
6.1 Bluetooth browser...............................................................................65
6.2 Bluetooth benchmark..........................................................................68
6.2.1 Benchmark server......................................................................69
6.2.2 Benchmark client.......................................................................72
Chapter 7 Summary and conclusions..................................................................75
7.1 Summary.............................................................................................75
7.2 Conclusions.........................................................................................76
7.3 Further work........................................................................................76
Appendix A BTBrowser.......................................................................................79
BTBrowserMIDlet.java.......................................................................79
Appendix B BTBenchmark..................................................................................93
Server.java...........................................................................................93
Client.java.........................................................................................103
StatusCanvas.java.............................................................................116
Appendix C KlingsLib........................................................................................121
BTServiceAttributeId.java................................................................121
BTProtocol.java.................................................................................127
BTServiceClass.java.........................................................................132
BTUUIDTool.java.............................................................................142
BluetoothInfoCanvas.java.................................................................144
BluetoothServiceRecordCanvas.java................................................150
CanvasHelper.java............................................................................162

VI

List of Tables
Table 2.1 Descriptions of Bluetooth protocol layers......................................................7
Table 2.2 Service record attributes...............................................................................14
Table 2.3 Bluetooth foundation profiles.......................................................................16
Table 3.1 CLDC packages...........................................................................................24
Table 3.2 MIDP 1.0 requirements................................................................................26
Table 3.3 MIDP 1.0 packages......................................................................................26
Table 3.4 MIDP 2.0 requirements................................................................................28
Table 3.5 MIDP 2.0 packages......................................................................................28
Table 3.6 JABWT packages.........................................................................................32
Table 5.1 RFCOMM connection parameters...............................................................56
Table 6.1 Benchmark results........................................................................................69

VII

List of Figures
Figure 2.1 The Bluetooth protocol stack........................................................................6
Figure 2.2 A typical piconet...........................................................................................8
Figure 2.3 Scatternet......................................................................................................9
Figure 2.4 Piconet with two nodes...............................................................................10
Figure 2.5 Scatternet with 3 nodes...............................................................................10
Figure 2.6 Piconet with 3 nodes...................................................................................11
Figure 2.7 The Service Discovery DataBase (SDDB).................................................13
Figure 2.8 Data element construct...............................................................................14
Figure 3.1 High level view of J2ME............................................................................21
Figure 3.2 CLDC position in J2ME architecture.........................................................23
Figure 3.3 MIDP position in J2ME architecture..........................................................25
Figure 3.4 MIDlet architecture overview.....................................................................29
Figure 3.5 MIDlet deployment.....................................................................................31
Figure 3.6 JABWT position in J2ME architecture.......................................................32
Figure 4.1 Screenshot of Impronto Simulator..............................................................36
Figure 4.2 The Nokia 6600..........................................................................................37
Figure 4.3 The Sony Ericsson P900.............................................................................38
Figure 6.1 Cached/known devices...............................................................................65
Figure 6.2 Initiating device discovery..........................................................................66
Figure 6.3 Device discovery in progress......................................................................66
Figure 6.4 Device discovery completed.......................................................................67
Figure 6.5 Service search on P900...............................................................................67
Figure 6.6 Service attributes........................................................................................68
Figure 6.7 Service attributes........................................................................................68
Figure 6.8 Benchmark server main menu....................................................................70
Figure 6.9 Benchmark server settings..........................................................................70
Figure 6.10 Benchmark server started.........................................................................71
Figure 6.11 Client connected to server.........................................................................71
Figure 6.12 Benchmark server, transfer results...........................................................72
Figure 6.13 Benchmark client, device discovery.........................................................72
Figure 6.14 Benchmark client, selection of data amount.............................................73
Figure 6.15 Benchmark client, transfer status screen..................................................73
Figure 6.16 Benchmark client, transfer finished .........................................................74

IX

Important acronyms
Connected Limited Device Configuration (CLDC).....................................................22
Generic Access Profile (GAP).....................................................................................15
Generic Connection Framework (GCF).......................................................................23
Java 2 Micro Edition (J2ME).........................................................................................2
Java APIs for Bluetooth Wireless Technology (JABWT).............................................2
Logical Link Control and Adaption Protocol (L2CAP)...............................................11
MIDlets.........................................................................................................................29
Mobile Information Device (MID)...............................................................................23
Mobile Information Device Profile (MIDP).................................................................22
RFCOMM....................................................................................................................12
Serial Port Profile (SPP)...............................................................................................15
Service Discovery DataBase (SDDB)..........................................................................13
Service Discovery Protocol (SDP).................................................................................7
Universally Unique IDentifier (UUID)........................................................................14
Wireless ToolKits (WTKs)..........................................................................................35

XI

1

1 Introduction
Wireless technologies are becoming more and more popular around the world.
Consumers appreciate the wireless lifestyle, relieving them of the well known “cable
chaos” that tends to grow under their desk. Nowadays, the world would virtually stop
if wireless communications suddenly became unavailable. Both our way of life and
the global economy are highly dependent on the flow of information through wireless
mediums like television and radio. Cellphones have become highly available during
the last decade. Now virtually everyone owns a cellphone, making people available
almost wherever they are. Many companies are highly dependent on their employees
having cellphones, some companies have even decided not to employ stationary
phone systems but instead use cellphones exclusively throughout the organization.

New wireless technologies are introduced at an increasing rate. During the last few
years the IEEE 802.11 [1] technologies have started to spread rapidly, enabling
consumers to set up their own wireless networks. This constitutes an important
change in how wireless communications are made available to consumers. Wireless
networks are no longer provided by big corporations alone, they can just as well be
implemented by individuals. Our society is becoming more and more dependent on
wireless communications as new areas of use are introduced.

The Bluetooth wireless technology is also spreading rapidly. The number of
Bluetooth chipsets shipped per year has doubled from 2002 to a total of 69 million
chipsets in 2003 [2]. The majority of these Bluetooth chipsets are used in mobile
phones. An interesting aspect is that consumers are highly dependent on having a
cellphone, and the Bluetooth technology is included in the majority of new
cellphones. The Bluetooth technology will therefore spread because of the general
need for cellphones. As an increasing number of useful Bluetooth applications
become available, many consumers will already have Bluetooth devices and be ready
to start using Bluetooth PANs (Personal Area Networks) where all their Bluetooth
devices communicate with one another [3].

The number of Java enabled mobile phones worldwide is over 250 million according
to a press release from Sun (dated February 19, 2004) titled: “Java technology is
everywhere, surpasses 1.5 billion devices worldwide” [4]. The number of Java
enabled mobile phones will continue to increase. Nokia states that they have already
shipped tens of millions Java enabled handsets and that most of their new handset
models announced will support Java [5].

Java enabled mobile phones have already been on the market for some years. Due to
the very resource constrained mobile phones available a few years ago, Java
applications were not very sophisticated and did not hit the mass-market the way
many had hoped. As seen in the rest of the software and hardware industry, games
play an important role in driving the development of both hardware and software
forward. It is therefore interesting to see that a large market has emerged lately for

2 Chapter 1 Introduction

Java games targeting mobile devices. Processing power, available memory, screen
size, and screen resolution are increasing as new Java enabled mobile devices enter
the market. Newly released Java applications are accordingly sophisticated, and will
help to spread the Java technology usage even further.

The Java APIs for Bluetooth Wireless Technology (JABWT) ties the Java technology
and the Bluetooth technology together. JABWT is made available in some of the
latest smartphones and will probably be available also in low-end cellphones in the
future. One can easily imagine different scenarios where JABWT would be useful,
e.g. the functionality of existing Java games is extended to support multi-player
games using Bluetooth connectivity. Other interesting scenarios emerge as well, such
as a consumer using a Java Bluetooth enabled mobile phone to pay for a soda by
connecting to a Bluetooth enabled soda vending-machine. A good prediction is that
JABWT will first find its use in multi-player Java games, making the Java and
Bluetooth technologies well-known to consumers. Thereafter we will probably see
other types of Java Bluetooth applications, such as small-amount payment
applications.

At the time of writing there are only two books discussing JABWT [6], [7]. These
books provide quite complex code samples for Java Bluetooth programming, making
it hard to grasp how JABWT is used. There are a few discussion boards with high
activity on the Internet where developers help each other [8], [9], [10]. Although
discussion boards may help developers with a specific problem, they usually do not
give a sufficient overview of the technology. This thesis gives a broad overview of
Java and Bluetooth technologies before discussing JABWT and its details. Code
samples are provided, showing how JABWT specific code is used in a J2ME
application. The amount of J2ME specific code is kept at a minimum in order to draw
attention to what is really important, namely the JABWT specific code.

The intended audience for this thesis are students working with Java and Bluetooth
technologies, and Java 2 Micro Edition (J2ME) application developers seeking
knowledge about the Bluetooth technology and JABWT. It is assumed that the reader
is familiar with the J2ME technology. Individuals whom are unfamiliar with any of
the technologies discussed should not expect to understand all the details in this
thesis. However, they will get a broad overview and may use this thesis as a starting
point for their studies on the involved technologies. References to in-depth
information are included throughout the thesis, enabling the interested reader to
quickly find relevant background information.

1.1 Structure of thesis
This thesis will give an introduction to the J2ME technology, the Bluetooth
technology, and JABWT available in mobile devices. The infrastructure used when
developing JABWT applications will be described. Programming with J2ME and

Chapter 1 Introduction 3

JABWT will be discussed thoroughly, highlighting functionality and irregularities in
JABWT. The sample applications developed during the work with this thesis will be
explained and demonstrated.

Chapter 2 gives an overview of the Bluetooth technology. Different aspects of the
technology are discussed, starting with a general overview of the Bluetooth
architecture. Important concepts such as Bluetooth networks, Bluetooth services,
Bluetooth profiles, device discovery, and service discovery are explained. Chapter 2
also looks into the Bluetooth security model.

Chapter 3 presents a brief introduction to the J2ME technology. It is assumed that the
reader is familiar with J2ME. Readers unfamiliar with J2ME will get an
understanding of what it is and may use the references to collect extensive
background information.

Chapter 4 provides an overview of the infrastructure needed to develop Java and
Bluetooth applications. Available development tools are discussed, in addition to the
Java Bluetooth enabled smartphones that were used to test Java Bluetooth
applications.

Chapter 5 contains code samples and explanations on how JABWT is used when
developing applications. Basic operations such as device discovery and service
discovery are described first, before more complex functionality is explained.

Chapter 6 describes the demo applications supplied in Appendix A and Appendix B,
the Bluetooth browser and Bluetooth benchmark applications.

Chapter 7 contains a summary of this thesis and some important conclusions.

5

2 Bluetooth

This chapter gives a brief introduction to the Bluetooth technology. The Bluetooth
architecture will be explained, in addition to basic Bluetooth actions like device
discovery and service discovery. Bluetooth services and some important details about
service records will be explained as well. After reading this chapter, developers
should have sufficient knowledge about the Bluetooth technology to start application
development with JABWT. For the interested reader, references to in-depth
information about the Bluetooth technology are included throughout the chapter. This
chapter is based on my supervisor's Bluetooth lectures available on his website [11],
the Bluetooth book by Bray and Sturman [12], and the Bluetooth Specification
version 1.1 [13] available for download on the Bluetooth Special Interest Group (SIG)
website [14].

Bluetooth is a low cost, low power, short-range radio technology intended to replace
cable connections between cellphones, PDAs and other portable devices. It can clean
up your desk considerably, making wires between your workstation, mouse, laptop
computer etc. obsolete. Ericsson Mobile Communications started developing the
Bluetooth system in 1994, looking for a replacement to the cables connecting
cellphones and their accessories. The Bluetooth system is named after a tenth-century
Danish Viking king, Harald Blåtand, who united and controlled Norway and
Denmark. The first Bluetooth devices hit the market around 1999.

The Bluetooth SIG is responsible for further development of the Bluetooth standard.
Sony Ericsson, Intel, IBM, Toshiba, Nokia, Microsoft, 3COM, and Motorola are some
of the companies involved in the SIG. The composition of the Bluetooth SIG is one of
the major strengths of the Bluetooth technology. The mixture of both noticeable
software and hardware suppliers participating in the further development of the
Bluetooth technology ensures that Bluetooth products are made available to end-
users. Microsoft supports Bluetooth in their Microsoft Windows Operating System
(OS), hence, Bluetooth software is made available to the vast majority of the desktop
software market. At the time of writing, Intel is including Bluetooth technology in
several new mainboard chipsets, especially for laptop computers. Both Nokia and
Sony Ericsson include Bluetooth technology in their latest cellphones. This all adds
up to a wide availability of the Bluetooth technology for end-users. Information of
more commercial nature about the Bluetooth technology is available on the Bluetooth
technology website [15].

This thesis describes the Bluetooth Specification version 1.1, the Bluetooth version
implemented in most mobile devices at the moment [13]. However, the Bluetooth 1.2
specification is already completed and the Bluetooth 2.0 specification is in the works.
At the time of writing, Enhanced Data Rate (EDR) Bluetooth has just been introduced
by the Bluetooth SIG, raising the gross air data rate from 1 Mbps to 2 Mbps or 3

6 Chapter 2 Bluetooth

Mbps. Devices conforming to these new specifications will probably show up shortly
after the completion of this Master thesis.

2.1 Bluetooth architecture
The Bluetooth specification aims to allow Bluetooth devices from different
manufacturers to work with one another, so it is not sufficient to specify just a radio
system. Because of this, the Bluetooth specification does not only outline a radio
system but a complete protocol stack to ensure that Bluetooth devices can discover
each other, explore each other's services, and make use of these services.

Applications

TCS SDP
OBEX WAP

RFCOMM

Logical Link Control and Adaption Protocol (L2CAP)

Host Controller Interface (HCI)

Link Manager Protocol

Baseband / Link Controller

Radio
Figure 2.1 The Bluetooth protocol stack

The Bluetooth stack is made up of many layers, as shown in Figure 2.1. The HCI is
usually the layer separating hardware from software and is implemented partially in
software and hardware/firmware. The layers below the HCI are usually implemented
in hardware and the layers above the HCI are usually implemented in software. Note
that resource constrained devices such as Bluetooth headsets may have all
functionality implemented in hardware/firmware. Table 2.1 gives a short description
of each layer shown in Figure 2.1.

Chapter 2 Bluetooth 7

Layer Description
Applications Bluetooth profiles guide developers on
how applications should use the protocol
stack
Telephony Control System (TCS ) Provides telephony services
Service Discovery Protocol (SDP) Used for service discovery on remote
Bluetooth devices
WAP and OBEX Provide interfaces to higher layer parts of
other communications protocols
RFCOMM Provides an RS-232 like serial interface
L2CAP Multiplexes data from higher layers and
converts between different packet sizes
HCI Handles communication between the host
and the Bluetooth module
Link manager Protocol Controls and configures links to other
devices
Baseband and Link Controller Controls physical links, frequency
hopping and assembling packets
Radio Modulates and demodulates data for
transmission and reception on air
Table 2.1 Descriptions of Bluetooth protocol layers

The interested reader will find further information about the layers of the Bluetooth
stack in the Bluetooth book by Bray and Sturman [12] and in the Bluetooth
specification [13].

Application developers do not need to know all the details about the layers in the
Bluetooth stack. However, an understanding of how the Bluetooth radio works is of
importance. The Bluetooth radio is the lowest layer of Bluetooth communication. The
Industrial, Scientific and Medical (ISM) band at 2.4 GHz is used for radio
communication. Note that several other technologies use this band as well. Wi-Fi
technologies like IEEE 802.11b/g and kitchen technologies like microwave ovens
may cause interference in this band [1].

The Bluetooth radio utilizes a signaling technique called Frequency Hopping Spread
Spectrum (FHSS). The radio band is divided into 79 sub-channels. The Bluetooth
radio uses one of these frequency channels at a given time. The radio jumps from
channel to channel spending 625 microseconds on each channel. Hence, there are
1600 frequency hops per second. Frequency hopping is used to reduce interference
caused by nearby Bluetooth devices and other devices using the same frequency band.
Adaptive Frequency Hopping (AFH) is introduced in the Bluetooth 1.2 specification


and is useful if your device communicates through both Bluetooth and Wi-Fi
simultaneously (e.g. a laptop computer with both Bluetooth and Wi-Fi equipment).
The frequency hopping algorithm can then avoid using Bluetooth channels
overlapping the Wi-Fi channel in use, hence avoiding interference between your own
radio communications.

Every Bluetooth device is assigned a unique Bluetooth address, being a 48-bit
hardware address equivalent to hardware addresses assigned to regular Network
Interface Cards (NICs). The Bluetooth address is used not only for identification, but
also for synchronizing the frequency hopping between devices and generation of keys
in the Bluetooth security procedures.

2.2 Piconet and scatternet
A piconet is the usual form of a Bluetooth network and is made up of one master and
one or more slaves. The device initiating a Bluetooth connection automatically
becomes the master. A piconet can consist of one master and up to seven active
slaves. The master device is literally the master of the piconet. Slaves may only
transmit data when transmission-time is granted by the master device, also slaves
may not communicate directly with each other, all communication must be directed
through the master. Slaves synchronize their frequency hopping with the master using
the master's clock and Bluetooth address.

Slave

Master Slave
E
A B

D
C
Slave

Slave
Figure 2.2 A typical piconet

Piconets take the form of a star network, with the master as the center node, shown in
Figure 2.2. Two piconets may exist within radio range of each other. Frequency


hopping is not synchronized between piconets, hence different piconets will randomly
collide on the same frequency.

When connecting two piconets the result will be a scatternet. Figure 2.3 shows an
example, with one intermediate node connecting the piconets. The intermediate node
must time-share, meaning it must follow the frequency hopping in one piconet at the
time. This reduces the amount of time slots available for data transfer between the
intermediate node and a master, it will at least cut the transfer rate in half. It is also
important to note that neither version 1.1 nor version 1.2 of the Bluetooth
specification define how packets should be routed between piconets. Hence,
communication between piconets cannot be expected to be reliable.

Piconet 1 Piconet 2

D Master
G
Master
Slave E Slave
A
B
F
C Slave/Slave

Slave
Slave

Figure 2.3 Scatternet

Role-switching enables two devices to switch roles in a piconet. Consider the
following example: You have two devices A and B. Device A connects to device B,
hence, device A becomes the master of the piconet consisting of devices A and B as
shown in Figure 2.4.


Master Slave

A B

Figure 2.4 Piconet with two nodes

Then a device C wants to join the piconet. Device C connects to the master device, A.
Since device C initiated the connection it will automatically become the master of the
connection between device C and device A. We now have two masters, hence, we
have two piconets. Device A is the intermediate node between these piconets, being
the master for device B and the slave for device C, as seen in Figure 2.5.

Slave/Master Slave

A B

C
Master
Figure 2.5 Scatternet with 3 nodes

Figure 2.6 shows that a role-switch between device A and device C will give us one
piconet where A is the master and both B and C are slaves. We see that when a new
device wants to be part of a piconet we actually need a role-switch to make this
happen, else we get a scatternet.


Master Slave

A B

C
Slave
Figure 2.6 Piconet with 3 nodes

2.3 Bluetooth links
Two types of physical links are defined in version 1.1 of the Bluetooth specification,
Synchronous Connection Oriented (SCO) links and Asynchronous ConnectionLess
(ACL) links. The SCO and ACL links are part of the baseband specification.

SCO links are intended for audio transmission. When setting up a SCO link time slots
are reserved for transmission of data, thus providing a Quality of Service (QoS)
guarantee. Lost or erroneous packages are not re-transmitted which makes sense for
voice transmissions. All SCO links operate at 64 kbps. A master device can have up
to three simultaneous SCO links at a time, all to the same slave or to different slaves.
Slave devices can have up to three SCO links to the Master device.

ACL links are intended for data communication. An ACL link provides error-free
transmission of data which means that lost or erronous packets are re-transmitted. No
QoS guarantee is provided. The maximum data rate at the application level is around
650 kbps for an ACL link. A master device can have a number of ACL links to a
number of different devices, but only one ACL link can exist between two devices.
User data is usually transferred to and from the Logical Link Control and Adaption
Protocol (L2CAP) layer of the Bluetooth stack. Application developers usually refer
to L2CAP and RFCOMM links when talking about Bluetooth links. To be precise,
L2CAP and RFCOMM are separate layers in the Bluetooth stack which rely on an
ACL physical link for data transmission.


L2CAP provides multiplexing between different higher layer protocols over a single
physical ACL link, enabling several logical data links to be set up between two
Bluetooth devices. L2CAP also provides segmentation and reassembly of packets
from higher layers. Different protocols use different packet sizes, some of these may
need to be segmented in order to be sent over an ACL link due to package size
constraints. An ACL packet can have a maximum of 339 bytes of payload data, while
an L2CAP packet can have a maximum of 65,535 bytes of payload data.

The RFCOMM layer emulates RS-232 serial ports and serial data streams. RFCOMM
relies on L2CAP for multiplexing multiple concurrent data streams and handling
connections to multiple devices. The majority of Bluetooth profiles make use of the
RFCOMM protocol because of its ease of use compared to direct interaction with the
L2CAP layer.

2.4 Device discovery (inquiry) and service discovery
Due to the ad-hoc nature of Bluetooth networks, remote Bluetooth devices will move
in and out of range frequently. Bluetooth devices must therefore have the ability to
discover nearby Bluetooth devices. When a new Bluetooth device is discovered, a
service discovery may be initiated in order to determine which services the device is
offering.

The Bluetooth Specification refers to the device discovery operation as inquiry.
During the inquiry process the inquiring Bluetooth device will receive the Bluetooth
address and clock from nearby discoverable devices. The inquiring device then has
identified the other devices by their Bluetooth address and is also able to synchronize
the frequency hopping with discovered devices, using their Bluetooth address and
clock.

Devices make themselves discoverable by entering the inquiry scan mode. In this
mode frequency hopping will be slower than usual, meaning the device will spend a
longer period of time on each channel. This increases the possibility of detecting
inquiring devices. Also, discoverable devices make use of an Inquiry Access Code
(IAC). Two IACs exist, the General Inquiry Access Code (GIAC) and the Limited
Inquiry Access Code (LIAC). The GIAC is used when a device is general
discoverable, meaning it will be discoverable for a undefined period of time. The
LIAC is used when a device will be discoverable for only a limited period of time.

Different Bluetooth devices offer different sets of services. Hence, a Bluetooth device
needs to do a service discovery on a remote device in order to obtain information
about available services. Service searches can be of a general nature by polling a
device for all available services, but can also be narrowed down to find just a single
service. The service discovery process uses the Service Discovery Protocol (SDP). A


SDP client must issue SDP requests to a SDP server to retrieve information from the
server's service records.

2.5 Bluetooth services
Bluetooth devices keep information about their Bluetooth services in a Service
Discovery DataBase (SDDB) as shown in Figure 2.7. The SDDB contains service
record entries, [13, p. 340], where each service record contains attributes describing a
particular service. Each service has its own entry in the SDDB.

SDDB

Service record 1 Service record 1
Service record 2 Attribute 1
Service record 3 Attribute 2

Figure 2.7 The Service Discovery DataBase (SDDB)

Remote devices can retrieve service records during service discovery and will then
possess all information required to use the services described. We see from Figure 2.7
that a service record has several attributes. Each attribute is assigned an attribute ID,
being a hexadecimal identifier. Table 2.2 shows the most common attributes' names,
IDs and data types. Note that only two attributes are required to exist in a service
record, the ServiceRecordHandle (attribute ID 0x0000) and the ServiceClassIDList
(attribute ID 0x0001) attributes. Usually there exist several additional attributes in
service records describing common Bluetooth services.

Attribute Name Attribute ID Attribute Value Type
ServiceRecordHandle 0x0000 32-bit unsigned integer
ServiceClassIDList 0x0001 Data Element Sequence (of
UUIDs)
ServiceRecordState 0x0002 32-bit unsigned integer
ServiceID 0x0003 UUID
ProtocolDescriptorList 0x0004 Data Element Sequence (of
UUIDs and protocol-specific
parameters) or Data Element
Alternative


Attribute Name Attribute ID Attribute Value Type
BrowseGroupList 0x0005 Data Element Sequence (of
UUIDs)
LanguageBaseAttributeIDList 0x0006 Data Element Sequence (of
language parameters for
supported languages)
ServiceInfoTimeToLive 0x0007 32-bit unsigned integer
ServiceAvailability 0x0008 8-bit unsigned integer
BluetoothProfileDescriptorList 0x0009 Data Element Sequence (of
UUIDs)
DocumentationURL 0x000A URL
ClientExecutableURL 0x000B URL
IconURL 0x000C URL
Table 2.2 Service record attributes

Different attributes contain values of various types and sizes. To cope with this, data
elements are used for storing values. A data element consists of a data element type
descriptor and a data field as seen in Figure 2.8. The data element type descriptor
contains information about the type and size of the data and the data field contains the
actual data. A remote device will then know what kind of data and how much data it
is receiving when retrieving a service attribute.

Header Data

Type Size

Figure 2.8 Data element construct

The Universally Unique IDentifier (UUID), [13, p. 345], is the data type used for
identifying services, protocols and profiles etc. A UUID is a 128-bit identifier that is
guaranteed to be unique across all time and space. The Bluetooth technology uses
different variants of UUIDs, short UUIDs and long UUIDs, to reduce the burden of
storing and transferring 128-bit UUID values. A range of short UUID values has been
pre-allocated for often-used services, protocols and profiles, and is listed in the
Bluetooth Assigned Numbers document on the Bluetooth Membership website [14].


More details about attributes can be found in the Bluetooth Specification 1.1 [13, Part
E], and in the book by Bray and Sturman [12, Ch. 11].

2.6 Bluetooth profiles
Bluetooth profiles provide a well defined set of higher layer procedures and uniform
ways of using the lower layers of Bluetooth. The profiles guide developers on how to
implement a given end-user functionality using the Bluetooth system. This section is
based on [3].

The profiles released with the Bluetooth specification version 1.1 are called
foundation profiles. Table 2.3 gives an overview and a short description of these
profiles.

Profile Description
Generic Access Profile (GAP) The basis for all profiles in the Bluetooth system.
The GAP defines basic Bluetooth functionality
like setting up L2CAP links, handling security
modes and discoverable modes
Serial Port Profile (SPP) Provides serial port (RS-232) emulation based on
the RFCOMM part of the Bluetooth stack
Dial Up Networking Profile Defines functionality for using a Bluetooth device
(DUNP) as a Dial Up Networking gateway
FAX Profile Defines functionality for using a Bluetooth device
as a FAX gateway
Headset Profile Defines the functionality required to do audio
transfer with e.g. a wireless Bluetooth headset
LAN Access Point Profile Defines functionality for using a Bluetooth device
as a LAN access point
Generic Object Exchange Profile Provides support for the OBjext EXchange
(GOEP) (OBEX) protocol over Bluetooth links
Object Push Profile Defines functionality for exchanging vCard and
vCalendar objects, based on the GOEP
File Transfer Profile Defines functionality for navigating through
folders and copying/deleting/creating a file or
folder on a Bluetooth device, based on the GOEP
Synchronization Profile Defines functionality for synchronizing Object
Stores containing IrMC objects (vCard,
vCalendar, vMessaging and vNotes objects)
between Bluetooth devices, based on the GOEP


Profile Description
Intercom Profile Enables Bluetooth devices to establish a direct
communication link similar to intercom
communcation
The Cordless Telephony Profile Enables Bluetooth devices to act as regular
cordless phones communicating with e.g. an
ISDN gateway
Table 2.3 Bluetooth foundation profiles

Using profiles ensure interoperability between different devices from different
Original Equipment Manufacturers (OEMs). Consumers should be able to buy a
cellphone from one vendor and a headset from another and have them working nicely
together assuming that both devices implement the headset profile. New profiles are
defined continuously by Bluetooth SIG Working groups.

2.7 Bluetooth qualification
This section is based on [12, Ch. 23-24]. New Bluetooth products cannot use the
Bluetooth brand for marketing purposes before the products have passed the
Bluetooth qualification program. This is to ensure interoperability between Bluetooth
devices. When a product has passed this qualification program consumers can be sure
that the product will work with other qualified Bluetooth products. The Bluetooth
Qualification website [16] contains information for companies who wish to get their
Bluetooth devices qualified. The requirements for qualification is split into four
categories:

• Bluetooth radio link requirements
• Bluetooth protocol requirements
• Bluetooth profile requirements
• Bluetooth information requirements

Qualification tests are carried out on samples of a Bluetooth product. Three levels of
Bluetooth qualification are used to ensure that a Bluetooth product meets the
qualification requirements:

• Qualification testing to ensure conformance with the Bluetooth core specification
• Interoperability testing to ensure that devices work with one another at the profile
level
• Checking documentation to ensure it conforms to the Bluetooth brand book


In addition to the qualification of sample products, all Bluetooth products have a test
mode which is used to test that the radio performance of the real products conform
with the samples used for regulatory and qualification testing.

2.8 Bluetooth security
Security is important when communicating without wires. If your device is
discoverable, anyone in the vicinity can do a device discovery and find your
Bluetooth device. They may determine which services your device is offering and try
to connect to them. Another problem is eavesdropping, which can be done very easily
when communicating without wires. In order to handle these threats, the Bluetooth
specification defines a security model based on three components: authentication,
encryption and authorization. In addition, three security modes are defined, enforcing
different levels of security. A security manager is used to handle the security
transactions in the Bluetooth system.

2.8.1 Security modes
Security modes are part of the GAP profile. All qualified Bluetooth devices must
have an implementation of the GAP profile, hence all Bluetooth devices will have
implemented a security mode. The OEM must decide which security mode to support
when implementing the GAP profile on a Bluetooth device. On more powerful
devices such as a laptop computer, the user may have the option to select the desired
security mode. The ability to select security modes is available in e.g. the Bluetooth
software accompanying 3COM USB Bluetooth devices. The GAP defines three
security modes:

1. No security
2. Service level enforced security
3. Link level enforced security

In security mode 1, devices will never initiate any security procedure. Support for
authentication is optional. This security mode is not seen in many devices at the time
of writing, it was probably used in early Bluetooth devices.

Security mode 2 is the security mode used for the majority of Bluetooth devices.
Security is enforced at the service level, hence the service decides whether security is
required or not. Note that in service mode 2 security procedures are initiated by the
higher Bluetooth layers after the Bluetooth link is created by the lower layers. This


enables developers to create services and decide if a service should require security.
Security mode 2 will be discussed further in Section 2.8.6.

In security mode 3, security procedures are initiated during the setup of a Bluetooth
link. If security measures fail, the link setup will fail. Observe that security
procedures are initiated by the lower layers of the Bluetooth stack in security mode 3.
Application developers have no influence on the security settings when setting up a
Bluetooth link. Security mode 3 is useful for Bluetooth devices which have factory
preset settings and is not configurable by the user, e.g. Bluetooth headsets.

2.8.2 Pairing and bonding (authentication)
Bonding is the procedure of a Bluetooth device authenticating another Bluetooth
device, and is dependent on a shared authentication key. If the devices do not share an
authentication key, a new key must be created before the bonding process can
complete. Generation of the authentication key is called pairing. The pairing process
involves generation of an initialization key and an authentication key, followed by
mutual authentication. The initialization key is based on user input, a random number
and the Bluetooth address of one of the devices. The user input is referred to as a
Personal Identification Number (PIN) or passkey and may be up to 128-bits long. The
passkey is the shared secret between the two devices. The authentication key is based
on random numbers and Bluetooth addresses from both devices. The initialization key
is used for encryption when exchanging data to create the authentication key, and is
thereafter discarded. When the pairing process is completed, the devices have
authenticated each other. Both devices share the same authentication key, often called
a combination key since both devices have contributed to the creation of the key.

When two devices have completed the pairing process they may store the
authentication key for future use. The devices are then paired and may authenticate
each other through the bonding process without the use of a passkey. Devices will
stay paired until one device requests a new pairing process, or the authentication key
is deleted on either of the devices. Storing the authentication key is useful for devices
frequently connecting to each other, such as a laptop computer frequently connecting
to the dial-up networking service on a cellphone. The bonding procedure can then
complete without user input and the user is relieved of figuring out a new passkey
every time he or she wants to connect to the Internet.

2.8.3 Encryption
When two devices have authenticated each other encryption may be requested for the
Bluetooth link by either of the devices. Before encryption can begin, the devices must
negotiate encryption mode and key-size for the encryption key. There are three
encryption modes:


• no encryption
• encrypt both point-to-point and broadcast packets
• only encrypt point-to-point packets

When only two devices are connected, the point-to-point packets encryption mode is a
natural choice. The no encryption mode will only be selected if either of the devices
do not support encryption. When encryption has been requested and both devices
support encryption, the size of the encryption key is negotiated. The master device
will then suggest its largest supported key-length. The slave device may then accept
or reject this key-length. If the slave accepts, all is well and encryption may be
started. If the slave rejects, the master can suggest a shorter key-length or decide to
terminate the connection. This procedure is repeated until the devices agree on a key-
length or the master decides to terminate the link. Key-lengths from 8-128 bits are
supported for encryption keys. This is due to export restrictions from the U.S. to some
countries.

2.8.4 Authorization
Authorization is the process of giving a remote Bluetooth device permission to access
a particular service. In order to be authorized the remote device must first be
authenticated through the bonding process. Access may then be granted on a
temporary or a permanent basis. The trust attribute is related to authorization, linking
authorization permissions to a particular device. A trusted device may connect to a
Bluetooth service, and the authorization process will complete successfully without
user interaction. This means that the previously mentioned user with the laptop
computer and cellphone may completely avoid user interaction with the cellphone
when connecting to the Internet. By marking the laptop computer as a trusted device
on the cellphone, the laptop computer may be authorized automatically when
connecting to the dial-up networking service on the cellphone.

2.8.5 Security manager
In order to keep track of which devices are trusted and the different levels of
authorization for different services, security information needs to be stored in security
databases. Two databases are used, one for devices and one for services. Several
layers need access to these security databases. The security manager allows uniform
access to the security databases for all layers and is responsible for entering and
extracting information from the security databases. Hence, all exchange of
information from the different layers and the security databases goes through the
security manager. Applications and protocols must register with the security manager
in order to use security features.


Other important tasks handled by the security manager are to query the user for a
passkey during the pairing process and query the user for an authorization response
when a remote device tries to connect to a service that requires authorization. The
security manager must also provide an user interface to configure security settings on
the device.

2.8.6 Security mode 2
The Bluetooth security white paper [17] defines a security architecture which may be
used to implement security mode 2 service level enforced security. Device security
levels are defined, splitting devices into three security categories:

• Trusted devices are bonded devices marked as trusted in the device database, and
can be given unrestricted access to all services.
• Known untrusted devices are bonded devices not marked as trusted in the device
database. Access to services may be restricted.
• Unknown devices are not paired. These devices are untrusted and access to services
may be restricted.

The security white paper also defines service security levels by splitting services into
three security categories:

• Open services with no security requirements. Any device can access these.
• Authentication-only services accessible to any bonded device.
• Authentication and authorization services accessible to trusted devices only.

When working with recent smartphones these categories are recognized in the menus
where devices can be bonded, and trust can be granted. This indicates that OEMs use
the Bluetooth security white paper when implementing security mode 2. Note that
with this implementation the user may not have as fine-grained control as he or she
may wish. It could be of interest to mark a device as trusted, but give it access to only
a subset of services. This is not possible, a trusted device will have access to all
services. The interested reader can download the Bluetooth security white paper from
the Bluetooth SIG website [14].

21

3 Java 2 Micro Edition (J2ME)

This chapter gives an overview of the J2ME technology. The J2ME architecture is
described in general before the components in the J2ME technology are introduced.
J2ME applications are also discussed in general, and it is explained how they are
made available to end users. Finally, JABWT is discussed, showing where it has its
place in the J2ME architecture.

J2ME is a highly optimized Java runtime environment. J2ME is aimed at the
consumer and embedded devices market. This includes devices such as cellular
telephones, Personal Digital Assistants (PDAs) and other small devices.

Profile

Libraries
Configuration
JVM

Host Operating System

Figure 3.1 High level view of J2ME

Figure 3.1 shows the J2ME architecture. Java 2 Standard Edition (J2SE) developers
should be familiar with Java Virtual Machines (JVMs) and at least one host Operating
System (OS). Profiles and configurations are introduced in J2ME and will be outlined
in Section 3.1.

The OS will vary on different mobile devices. Some devices run the Symbian OS
[18], others run some other OS developed by the manufacturer. It is therefore up to
the manufacturers to implement a JVM for their specific platform compliant with the
JVM Specification and Java Language Specification.

22 Chapter 3 Java 2 Micro Edition (J2ME)

3.1 Configurations and profiles
Mobile devices come with different form, features and functionality, but often use
similar processors and have similar amounts of memory. Therefore configurations
were created, defining groups of products based on the available processor power and
memory of each device. A configuration outlines the following:

• The Java programming language features supported
• The JVM features supported
• The basic Java libraries and Application Programming Interfaces (APIs)
supported

There are two standard configurations for the J2ME at this time, Connected Device
Configuration (CDC) and Connected Limited Device Configuration (CLDC). The
CDC is targeted toward powerful devices like Internet TVs and car navigation
systems. The CLDC is targeted toward less powerful devices like mobile phones and
PDAs. The vast majority of Java enabled mobile devices available to consumers
today use CLDC. The CDC will therefore not be discussed in this thesis. The
interested reader can find more information about CDC on Sun Microsystems' CDC
product website [19].

A profile defines a set of APIs which reside on top of a configuration and offers
access to device specific capabilities. The Mobile Information Device Profile (MIDP)
is a profile to be used with the CLDC and provides a set of APIs for use by mobile
devices. These APIs include classes for user interface, persistent storage and
networking. The MIDP is outlined in Section 3.3. Specifications, APIs and other
J2ME related information can be found on Sun Microsystems' J2ME website [20].

3.2 Connected Limited Device Configuration (CLDC)
The CLDC is the result of a Java Community Process [21] expert group JSR 30 [22]
consisting of a number of industrial partners.

The main goal of the CLDC Specification is to standardize a highly portable
minimum-footprint Java application development platform for resource-constrained,
connected devices.

Chapter 3 Java 2 Micro Edition (J2ME) 23

MIDP

Libraries
CLDC
KVM


Figure 3.2 CLDC position in J2ME architecture

Figure 3.2 shows that CLDC is core technology designed to be the basis for one or
more profiles. CLDC defines a minimal subset of functionality from the J2SE
platform. Hence, the CLDC does not define device-specific functionality in any way,
but instead defines the basic Java libraries and functionality available from the Kilo
Virtual Machine (KVM). The KVM got its name because it includes such a small
subset of the J2SE JVM that its size can be measured in kilobytes.

It is important to note that the CLDC does not define any optional features. Hence,
developers are sure their applications will work on any device with a compliant
CLDC implementation.

3.2.1 Generic Connection Framework (GCF)
During development of the CLDC the familiar J2SE java.io and java.net APIs
were considered to large to fit in memory of a resource constrained Mobile
Information Device (MID), so the GCF was created as a replacement. As the name
implies, the GCF provides a generic approach to connectivity. The GCF is used to
create connections such as datagram or stream connections. JABWT makes use of the
GCF when creating Bluetooth links. This way, the Java code used to create a
Bluetooth link is equivalent to the Java-code used to create other types of
communication links. The GCF is defined in the javax.microedition.io API.

3.2.2 CLDC versions and requirements
Two versions of the CLDC have been defined, version 1.0 and version 1.1. CLDC 1.1
adds a few new features over CLDC 1.0. Floating point support is the most important
feature added. Several minor bugfixes have also been added. CLDC 1.1 is intended to
be backwards compatible with version 1.0. Developers should note that the minimum
memory requirement has been raised from 160 KB in version 1.0 to 192 KB in
version 1.1 due to the added floating point support.


Package Provides
java.io Provides classes for input and output through data
streams
java.lang Provides classes that are fundamental to the Java
programming language
java.lang.ref Provides support for weak references
java.util Contains the collection classes, and the date and time
facilities
javax.microedition.io Classes for the GCF
Table 3.1 CLDC packages

CLDC consists of the Java packages shown in Table 3.1. Observe that GUI-libraries
and the java.net library are unavailable. All packages are subsets of the
corresponding packages from J2SE, except the javax.microedition.io
package which is introduced in the CDLC. Java.io provides basic input and output
streams, but not file streams or other libraries for persistent storage. The streams from
java.io are used with stream connections from the javax.microedition.io
package. Note that user interface, networking support and persistent storage are
addressed by the MIDP.

One does not usually develop programs based solely on the packages provided by the
CLDC since they only provide the most basic functionality from J2SE. Downloading
a java program based solely on the CLDC to a cellular phone would actually be
impossible. These devices only support applications based on MIDP, which implies
the use of CLDC. Hence, we use the CLDC and MIDP in combination.

Specifications, APIs and other CLDC-related information are available at Sun
Microsystems' CLDC product website [23].

3.2.3 CLDC security
The security model of the CLDC is defined at three different levels, low-level
security, application-level security and, end-to-end security [24]. Low-level security
ensures that the application follows the semantics of the Java programming
language. It also ensures that an ill-formed or maliciously encoded class file does not
crash or in any other way harm the target device. In a standard Java virtual machine
implementation this is guaranteed by a class file verifier, which ensures that the
bytecodes and other items stored in class files cannot contain illegal instructions,
cannot be executed in an illegal order, and cannot contain references to invalid
memory locations or memory areas outside the Java object memory. However, the


conventional J2SE class verifier takes a minimum of 50 kB binary code space and
typically at least 30-100 kB of dynamic Random Access Memory (RAM) at runtime.
This is not ideal for small, resource constrained devices. Because of this, a different
approach is used for class file verification in CLDC. Class files are preverified off-
device, usually on the workstation used by the developer to compile the applications.
The preverification process will add some information to the classes, making runtime
verification much easier. The result is that the implementation of the class verifier in
Sun's KVM requires about 10 kB of Intel x86 binary code and less than 100 bytes of
dynamic RAM at runtime for typical class files.

Application-level security means that the application will run in the CLDC sandbox-
model. The application should only have access the resources and libraries permitted
by the Java application environment. This means that the application programmer
must not be able to modify or bypass the standard class loading mechanisms of the
virtual machine. The CLDC sandbox model also requires that a closed, predefined set
of Java APIs is available to the application programmer, defined by the CLDC,
profiles (e.g. MIDP) and manufacturer-specific classes. The application programmer
must not be able to override, modify, or add any classes to the protected java.*,
javax.microedition.*, profile-specific or manufacturer-specific packages.

End-to-end security usually requires a number of advanced security solutions (e.g.
encryption and authentication). The CLDC expert group decided not to mandate a
single end-to-end security mechanism. Therefore, all end-to-end security solutions are
assumed to be implementation dependent and outside the scope of the CLDC
specification.

3.3 Mobile Information Device Profile (MIDP)
The MIDP is a set of APIs that resides on top of the CLDC as shown in Figure 3.3,
providing features such as user interface, networking support and persistent storage.
Two version of the MIDP exist at the time of writing, MIDP 1.0 and MIDP 2.0. They
will both be outlined in this chapter.

MIDP

Libraries
CLDC
KVM


Figure 3.3 MIDP position in J2ME architecture


Specifications, APIs and other MIDP-related information are available at Sun
Microsystems' MIDP website [25].

3.3.1 MIDP version 1
The MIDP version 1.0a is the result of the work carried out by a Java Community
Process expert group, JSR 37 [26], consisting of a number of industrial partners. The
MIDP 1.0a specification defines the architecture and the associated APIs needed for
application development for mobile information devices. The MIDP targets MIDs. To
be classified as a MID, a device should have the minimum characteristics listed in
Table 3.2:

Display: Pixels: 96x54
Display depth: 1-bit
Pixel shape (aspect ratio): approximately 1:1
Input: One- or two-handed keyboard or touch screen
Memory: 128 KB of non-volatile memory for the MIDP
components
8 KB of non-volatile memory for application-
created persistent data
32 KB of volatile memory for the Java runtime
environment
Networking: Two-way, wireless, possibly intermittent, with
limited bandwidth
Table 3.2 MIDP 1.0 requirements

The MIDP adds a few packages on top of the CLDC, shown in Table 3.3:

Package Provides
javax.microediton.lcdui Provides classes for user interface
Defines MIDP applications and the interactions
javax.microedition.midlet between the application and the environment in
which the application runs
Provides persistent storage (Record Management
javax.microedition.rms System)

Table 3.3 MIDP 1.0 packages


Since these packages are added on top of the CLDC, the MIDP API will also include
all CLDC packages. It is worth noting that the MIDP adds a few extra interfaces and
classes to existing packages in the CLDC. One of these is the HttpConnection
interface which gives a framework for HTTP connections, by extending the
functionality in the GCF. The TimerTask class in java.util is another example.
Developers should therefore use the MIDP API when programming for MIDs, thus
having access to all classes and interfaces provided by both the CLDC and the MIDP.

Application management in terms of fetching, installing, selecting, running and
removing MIDlets is not specified by the MIDP 1.0a. These issues are handled by the
Application Manager, which is implemented in a device specific way by the OEM.
Hence, application management is handled in a device specific way. Note that
application management is specified in the new MIDP 2.0 specification.

The MIDP 1.0a relies on the security model of the CLDC and specifies no additional
security features except the semantics implied by the MIDP application model. The
CLDC security model takes care of sufficient low-level and application-level
security. Hence, neither the CLDC or the MIDP 1.0a addresses end-to-end security.
This was first introduced in MIDP 2.0.

3.3.2 MIDP version 2
The MIDP version 2.0 is the result of the Java Community Process expert group JSR-
118 [27]. The MIDP 2.0 specification defines an enhanced architecture and the
associated APIs needed for application development for mobile information devices.
The specification is based on the MIDP 1.0 specification, providing backwards
compatibility so that MIDlets written for MIDP 1.0 can execute in MIDP 2.0
environments.

Display: Pixels: 96x54
Display depth: 1-bit
Pixel shape (aspect ratio): approximately 1:1
Input: One- or two-handed keyboard or touch screen
Memory: 256 KB of non-volatile memory for the MIDP
components
8 KB of non-volatile memory for application-created
persistent data
128 KB of volatile memory for the Java runtime
environment


Networking: Two-way, wireless, possibly intermittent, with
limited bandwidth
Sound: The ability to play tones, either via dedicated
hardware or via software algorithm
Table 3.4 MIDP 2.0 requirements

Table 3.4 shows that requirements for display, input and networking are the same as
for MIDP 1.0. Memory requirements have been raised in the MIDP 2.0 specification.
There must be 256 KB of non-volatile memory for the MIDP implementation, beyond
what is required for the CLDC and 128 KB of volatile memory for the Java runtime.
Requirements for sound have been added. The ability to play tones is now made a
requirement.

MIDP 2.0 is backwards compatible with MIDP 1.0, hence it provides all functionality
defined in the MIDP 1.0 specification. In addition it provides Over-The-Air (OTA)
provisioning. This feature was left to OEMs to provide in the MIDP 1.0 specification.
An enhanced user interface has been defined, making applications more interactive
and easier to use. Table 3.5 shows the packages provided by MIDP 2.0.

Package Provides
javax.microediton.lcdui Provides classes for user interface
Defines MIDP applications and the
javax.microedition.midlet interactions between the application and the
environment in which the application runs
Provides persistent storage (Record
javax.microedition.rms Management System)

javax.microedition.lcdui.game Provides functionality useful for game
development
javax.microedition.media Provides the Audio Building Block (ABB)
javax.microedition.pki Provides functionality for handling
certificates
Table 3.5 MIDP 2.0 packages

Media support has been added through the ABB, giving developers the ability to add
tones, tone sequences and WAV files even if the Mobile Media API (MMAPI)
optional package is not available.

Game developers now have access to a Game API providing a standard foundation for
building games. This API takes advantage of native device graphic capabilities.


MIDP 2.0 adds support for HTTPS, datagram, sockets, server sockets and serial port
communication.

Push architecture is introduced in MIDP 2.0. This makes it possible to activate a
MIDlet when the device receives information from a server. Hence, developers may
develop event driven applications utilizing carrier networks. An example of this could
be a SMS MIDlet, which would be activated when a new incoming SMS arrived at
the device.

End-to-end security is provided by HTTPS and SSL/TLS protocol access over the IP
(Internet Protocol) network. The ability to set up secure connections is a leap forward
for MIDP programming. A wide range of application models require encryption of
data and may now utilize the security model of MIDP 2.0 based on open standards.

3.4 MIDlets
MIDP applications are called MIDlets. Even though Figure 3.4 defines MIDlets as
applications built using the MIDP and CLDC only, one usually also refer to OEM-
specific applications as MIDlets. MIDlets are usually distributed in MIDlet suites,
available on the Internet through WAP.

OEM-Specific Native
MIDP Applications
Applications Applications

OEM-Specific
Classes

MIDP
CLDC
Native System Software
MID
Figure 3.4 MIDlet architecture overview


The MIDP defines an application model to allow the limited resources of the device
to be shared by multiple MIDlets. The application model defines the following:

• What a MIDlet is
• How it is packaged
• Runtime environment available to the MIDlet
• The MIDlet's behavior so that the device can manage its resources
• Packaging of MIDlets forming a MIDlet-suite

3.4.1 OEM-specific applications
OEM-specific applications rely on OEM-specific classes. Both Nokia and Sony
Ericsson have their own classes for user interface and device specific functionality.
E.g. vibration is provided through these specific classes. One of the main advantages
of MIDlets is their portability. If you use OEM-specific classes you sacrifice this
portability. Using Nokia classes will for certain give you an error if you run your
MIDlet on a Sony Ericsson device.

3.4.2 MIDlet suites
MIDlets are usually available through MIDlet suites. A MIDlet suite consists of two
files, a .jar and a .jad file. The Java ARchive (JAR) file contains compiled classes in a
compressed and preverified format. Several MIDlets may be included in a MIDlet
suite. Hence, the JAR file will contain all these MIDlet classes. This enables multiple
MIDlets to share resources, like common libraries included in the MIDlet suite or data
stored on the device. Because of security constraints, a MIDlet may only access the
resources associated with its own MIDlet suite. This applies to all resources, such as
libraries it may depend on or data stored on the MID.

The Java Application Descriptor (JAD) file is a plain text file containing information
about a MIDlet suite. All MIDlets must be named in this file, the size of the JAR file
must be included (and be correct!) and the URL to the JAR file must be present. In
addition, the MIDlet suite version number is included here. This is essential
information for a MID. The MID will always download the JAD file first and inspect
its contents. If the MIDlet suite is already installed, it will know if a newer version is
available. The size of the JAR file is important information, the MID can determine if
there is enough memory available to install the MIDlet suite. If all is well the MID
can go to the supplied URL and download the JAR file. Other attributes may be
included as well. Midlet vendor and other information may be included on a nice-to-
know basis. The MIDP specifications list available attributes and can be downloaded
from the respective JSR web pages [26], [27].


3.4.3 MIDlet deployment
MIDlet suites can be deployed to a webserver and made available for download.
Deploying to a webserver is the most common method for making MIDlet suites
widely available, but MIDlet suites may also be transferred to a MID using e.g. a
Bluetooth connection or a cable connection. The Java Bluetooth applications
described later in this thesis are deployed to the author's webserver and may be
downloaded through a HTTP or WAP enabled browser.

Figure 3.5 shows that a mobile device may connect to the Internet by using a GSM or
GPRS connection. A MIDlet can then be downloaded from a webserver on the
Internet, simply by entering the URL to the desired MIDlet's .jad file in a HTTP or
WAP browser.

Webserver
w/MIDlets

Internet

GSM/GPRS connection

Mobile device
Figure 3.5 MIDlet deployment


3.5 Java APIs for Bluetooth Wireless Technology (JABWT)
JABWT was defined by a Java Community Process expert group JSR-82 [28]. The
JABWT specification defines an optional J2ME package for Bluetooth wireless
technology.

OEM-Specific Native
MIDP Applications
Applications Applications

OEM-Specific
Classes

MIDP + JABWT
CLDC
Native System Software
MID
Figure 3.6 JABWT position in J2ME architecture

Figure 3.6 shows that JABWT operates on top of the CLDC and is intended to extend
the capabilities of profiles like the MIDP. JABWT use the GCF, defined in the CLDC
specification, for Bluetooth communication. JABWT consists of two packages, listed
in Table 3.6.

Package Provides
javax.bluetooth The core Bluetooth API.
javax.obex The Object Exchange (OBEX) API.
Table 3.6 JABWT packages

These packages are separate optional packages so the CLDC implementation may
include either of the packages or both of them.

The javax.bluetooth package provides an API for device discovery and service
discovery (see Section 2.4). In addition it provides functionality for setting up services
of your own and customization of local service records. Setting up L2CAP and
RFCOMM connections is available through an extension to the GCF from the CLDC.


The javax.obex package provides an API for the OBject EXchange (OBEX)
protocol. This package is not implemented on the Nokia 6600 smartphone. It is not
tied to the Bluetooth API alone but is intended to be of more general use. At the time
of writing the javax.obex package is not implemented on any available
smartphones, hence it will not be discussed in this thesis.

3.5.1 Security
This section is based on [7, Sec. 3.2]. The JABWT specification itself does not define
any security models. It depends on the security models available through the
Bluetooth stack. However, it does define how JABWT should interact with the lower
layers in the Bluetooth stack responsible for security features. The device must have a
Bluetooth Control Center (BCC) to which JABWT applications can direct their
security requests. The BCC is the central authority for local Bluetooth device settings.
It controls security settings and provides lists of devices both known and trusted by
the local device. The BCC is responsible for pairing devices and providing
authorization for connection request. All of these functions must be included in the
BCC. It is not clear what the relationship between the BCC and the Bluetooth security
manager is. A natural assumption is that the BCC relies on the Bluetooth security
manager to carry out security related actions. The security manager is discussed in
Section 2.8.5.

The BCC may have other capabilities like setting the Bluetooth friendly-name of the
device, setting timeouts for the baseband layer, determining how connectable and
discoverable modes are set, resetting the local device or enumerating services on the
local device. This BCC functionality is implementation dependent and may vary
between OEMs an their devices. Some implementations may provide a GUI to the
BCC while others provide hard-coded defaults in the BCC. For example, a headset
will provide only defaults in the BCC since it does not have an input device or screen.
When sending a request to the BCC one should always check if the request was
fulfilled by the BCC. One is not guaranteed that the BCC can fulfill the request at the
given time.

35

4 Infrastructure

Software developers have a choice of platform and development tools. This chapter
describes the infrastructure needed to develop Java Bluetooth applications. In the
initial face of writing this thesis, available Java Bluetooth application development
tools were explored. It was not clear how JABWT would be made available in
consumer devices, since there actually were no such devices available at the time.
Several vendors, such as Atinav and Rococo amongst others, offered JABWT
implementations and Bluetooth stacks implemented in Java. A decision had to be
made on which stack to use. During the fall of 2003 the Nokia 6600 smartphone was
released as the first device implementing JABWT. Shortly after, the Sony Ericsson
P900 smartphone was released being the second device on the market providing
JABWT.

4.1 Linux workstation
Linux is the OS of choice as Java development platform for the NoWires research
group [29]. There are several Linux distributions to choose from and most of them are
available for free. During the process of selecting development tools for Java
Bluetooth programming it came clear that all necessary development tools for J2ME
application development were available for the Linux platform, as well as the
Microsoft Windows platform. RedHat Linux 9 has been the platform for all the work
with this thesis and have produced a series of how-to documents explaining how to
get a Bluetooth USB dongle working, installing development tools etc. The interested
reader should consult the website related to this thesis [30].

4.2 Sun wireless toolkits
Sun provides Wireless ToolKits (WTKs) which enables development, preverification
and packaging of MIDlet suites. There are toolkits available for both MIDP 1.0 and
MIDP 2.0 application development. These toolkits include emulators, enabling
developers to test their applications before they are deployed to a J2ME enabled
device. In addition, simple graphical tools are available for debugging and building
MIDlet suites. Several Integrated Developer Environments (IDEs) support the WTKs,
such as NetBeans, JBuilder and Eclipse. If the WTKs are used from an IDE, MIDlet
suites may be built, preverified and packaged automatically. This is highly
recommended in the long run. The WTKs are available for download at Sun
Microsystems' wireless toolkit web pages [31].

36 Chapter 4 Infrastructure

4.3 Rococo Impronto simulator
The Impronto simulator is developed by Rococo Software Ltd. and can be purchased
through their website [32]. The Impronto simulator provides a simulation of a
complete Bluetooth environment and enables development of Java Bluetooth
applications without the need for Bluetooth hardware. The simulator supports both
J2ME and J2SE applications, enabling developers to have J2ME and J2SE Java
applications communicating with each other. J2ME applications run in the emulator
from the Sun wireless toolkit 1.04 integrate with the simulator without problems.
Bluetooth MIDlets may therefore be fully developed and extensively tested before on-
device testing commences. It is important to note that no emulator or simulator can
replace on-device testing, but they can save developers a lot of time during the initial
development and testing phases. Simulated Bluetooth devices are visualized in the
simulator, as shown in Figure 4.1.

Figure 4.1 Screenshot of Impronto Simulator

Simulated devices are easily configurable, and device configurations may be saved
for future use. This way, developers may create simulated devices with a variety of
capabilities and settings for use in application testing.

Chapter 4 Infrastructure 37

4.4 Smartphones
During the work with this thesis two smartphones were used to test JABWT
applications, the Nokia 6600 and the Sony Ericsson P900. These were the first two
mobile phones to support JABWT.

4.4.1 Nokia 6600
The Nokia 6600 was the first smartphone to be released with support for JABWT. It
was also one of the first mobile phones to support MIDP 2.0 Java applications. The
Nokia 6600 has a 104 MHz ARM processor, 6 MB internal memory and a 32 MB
Multimedia Memory Card (MMC). These specifications show what consumers can
expect from future smartphones.

Figure 4.2 The Nokia 6600

During the work with this thesis JABWT applications were deployed to the 6600
using Bluetooth links. However, the 6600 does provide HTTP connectivity by both
GSM and GPRS, and includes both a WAP browser and the Opera web-browser. Java
applications can therefore also be downloaded from the Internet.

4.4.2 Sony Ericsson P900
The Sony Ericsson P900 smartphone was the second smartphone with JABWT
support available on the market. It features a 156 MHz ARM processor, 16 MB

38 Chapter 4 Infrastructure

internal memory and a 32 MB Memory Stick Duo memory card. The P900 also
provides support for MIDP 2.0 applications. As with the Nokia 6600, Java
applications may be deployed to the P900 using Bluetooth links, or via the Internet
using GSM or GPRS connections. The P900 includes a WAP browser and a XHTML
browser.

Figure 4.3 The Sony Ericsson P900

JABWT was initially not available in the P900. Through Sony Ericsson's software
update service, the P900 software can be upgraded. In the latest releases of the P900
software, JABWT is available.

4.5 Web server, www.klings.org/nowires/
In order to make MIDlet suites available on the Internet, a web server is needed.
Fortunately, the author was already running a Linux powered web server hosting his
personal domain when starting the work on this thesis. With some minor
configuration changes the web server could be used to publish MIDlet suites. The
web-server is running the Fedora Core 1 Linux distribution, with Apache as the web
server software. The web pages describing this thesis [30] are also served from this
server. The interested reader can download the sample applications discussed in
Chapter 6 from these web pages.

The web pages have become quite popular, especially the collection of How-Tos
describing how to install and use various software needed to develop Java Bluetooth
applications. At the time of writing the average number of unique visits per month is
nearly 2000. In April 2004 the Bluetooth browser application was downloaded 58

Chapter 4 Infrastructure 39

times. There are postings from several developers on multiple developer forums
referring to the web pages, generating increased traffic to the website. This confirms
that there is an audience for this thesis.

4.6 IDEs
During the work with this thesis several IDEs have been explored. Many IDEs exist
for J2SE development, but it was not clear how many IDEs were usable for J2ME
development. Three IDEs were explored, NetBeans, Jbuilder and Eclipse.

The NetBeans IDE [33] is easy to use and provides all the basic functionality
expected by an IDE. Code completion, organizing projects and CVS (Concurrent
Versions System) [34] integration are provided. One of the really helpful features of
NetBeans is its ability to show JavaDoc for suggested methods during code
completion. There were no problems using the Impronto simulator with NetBeans.
The update feature was also a nice feature, enabling easy updates and easy
installation of new modules to the IDE. Integrating the WTK1.x with NetBeans was
very easy thanks to the automatic installation procedure. Unfortunately the WTK2.x
was not available for automatic download and installation, and was hard to integrate
manually. Some instability was experienced with the IDE, it would sometimes hang.
NetBeans was not the most responsive IDE either, so after a while other IDEs were
explored.

Borland JBuilder [35] is great software. The JBuilder IDE was tested for a 30-day
trial period. With the JBuilder Mobile Edition add-on package a developer has
everything he or she needs for developing J2ME applications. There were no
problems using the Impronto simulator with the JBuilder IDE. The only downside
with Borland JBuilder Mobile edition is that it is quite expensive. Due to a limited
research budget a switch to the Eclipse IDE was made.

The Eclipse IDE [36] is also great software. It is open-source and freely available.
Using native GUI libraries, it gives the developer a much better look-and-feel than the
other IDEs. Eclipse is a framework for Java development, meaning that its
functionality can be extended by the use of plugins. One suitable plugin was found
for J2ME application development during the work with this thesis, the EclipseME
plugin [37]. With the EclipseME plugin installed, MIDlet suites can be created easily
with the Eclipse IDE. Unfortunately there is a bug in the EclipseME plugin at the
time of writing, which will make Eclipse start the J2ME emulator without external
libraries supplied as an argument to the emulator. This will cause a problem, since the
emulator needs an external Bluetooth library to communicate with the Impronto
simulator. To work around this problem, the emulator can be started from command-
line with correct arguments. The author has filed a bug report to the EclipseME
developer so this issue will hopefully be resolved in the near future. MIDlets which
do not rely on external libraries are not affected by this issue.

41

5 J2ME and JABWT
programming

This chapter will give a thorough description on how to program with JABWT and
J2ME. Code samples are provided throughout the chapter, aiming to show the reader
how a complete Bluetooth MIDlet is built. This chapter is partly based on [7]. The
code samples in this chapter are simplified as much as possible, highlighting the
Bluetooth specific Java code instead of describing both J2ME and JABWT issues
simultaneously. The event-driven nature of J2ME applications tend to raise the
complexity of the source code, making it difficult to understand the structure of the
application. The simplified code samples provided in this chapter should make it
easier for the reader to understand JABWT programming. It is assumed that the
reader is familiar with J2ME programming. Readers who lack general knowledge
about J2ME programming should consult [38].

The first code samples provided in this chapter show the structure of a Bluetooth
MIDlet. Functionality will be added to these code samples as new functionality is
explained. Note that these code samples are not fully functional MIDlets. However,
they can be used as a starting point for a complete application. Method declarations
have font typeface bold to increase the readability of the code.

5.1 Structure of Bluetooth MIDlet
This section shows the structure in a Java/Bluetooth MIDlet. Several MIDlet
examples are available on Sun Microsystems' Mobility website [39].

Usually an event-driven MIDlet with no Bluetooth support looks like this:

import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.Displayable;
import javax.microedition.midlet.MIDlet;

public class YourMidlet extends MIDlet implements CommandListener {

public void startApp() {

}

public void pauseApp() {

42 Chapter 5 J2ME and JABWT programming

}

public void destroyApp(boolean unconditional) {

}

public void commandAction(Command c, Displayable d) {

}
}

The first three methods, startApp(), pauseApp() and destroyApp() are
needed for any MIDlet. They come from extending the MIDlet class. The next
method, commandAction() comes from the CommandListener interface. This
is needed to catch command events. The MIDlet is extended to support Bluetooth
communication in the next code sample.

During device discovery and service discovery, events will be delivered to a
DiscoveryListener object when devices or services are found or the device
discovery or service discovery is completed. An object implementing the
DiscoveryListener interface is used to catch these events. The MIDlet will then
look like this:

import javax.bluetooth.DiscoveryListener;
import javax.bluetooth.DeviceClass;
import javax.bluetooth.ServiceRecord;
import javax.bluetooth.RemoteDevice;

public class YourMidlet extends MIDlet implements CommandListener,
DiscoveryListener {


}


}


}


}

Chapter 5 J2ME and JABWT programming 43

public void deviceDiscovered(RemoteDevice remoteDevice,
DeviceClass deviceClass) {

}

public void inquiryCompleted(int param) {

}

public void serviceSearchCompleted(int transID, int respCode) {

}

public void servicesDiscovered(int transID,
ServiceRecord[] serviceRecord) {

}
}

The last four methods, deviceDiscovered(), inquiryCompleted(),
serviceSearchCompleted() and servicesDiscovered() are used to
catch events during device discovery and service discovery. Device discovery and
service discovery will be outlined in the two next sections.

5.2 Device discovery (Inquiry)
Device discovery, introduced in Section 2.4, is the first step required when browsing
nearby Bluetooth devices. When we have discovered nearby devices we can find out
which services they offer. Note that no UI specific code is included in the following
examples, only Bluetooth specific code.

To use any Bluetooth related methods you need to obtain a reference to the
LocalDevice object by calling the LocalDevice.getLocalDevice()
method. The obtained LocalDevice object gives access to Bluetooth properties for
the device, such as the Bluetooth address, friendly name and discovery mode. We will
use the LocalDevice object to obtain a DiscoveryAgent object. The
DiscoveryAgent object is used for device discovery and service discovery.

The MIDlet now looks like this:

import java.util.Vector;
import javax.bluetooth.BluetoothStateException;
import javax.bluetooth.DiscoveryAgent;
import javax.bluetooth.LocalDevice;



public class yourMIDlet extends MIDlet implements CommandListener,
DiscoveryListener {

private LocalDevice local = null;
private DiscoveryAgent agent = null;

private Vector devicesFound = null;


/* Add your MIDlet specific code here.
* You probably want to show the user
* a welcome screen.
* The call to doDeviceDiscovery() is
* here for the example's sake. You
* should call doDeviceDiscovery() when
* the user actively asks for it.
*/

doDeviceDiscovery();
}

}

}


}


}


}

}

}


private void doDeviceDiscovery() {

try {
local = LocalDevice.getLocalDevice();
}catch (BluetoothStateException bse) {

// Error handling code here
}

agent = local.getDiscoveryAgent();

devicesFound = new Vector();

try {

if(!agent.startInquiry(DiscoveryAgent.GIAC,this)) {

// Inquiry not started, error handling code here
}
}catch(BluetoothStateException bse) {

}
}

}

Device discovery is started using the LocalDevice and DiscoveryAgent
objects. Observe that the doDeviceDiscovery() method is called in the
startApp() method. Searching with the GIAC parameter will find devices which
are general discoverable (see Section 2.4). The DiscoveryListener parameter is
this, meaning our MIDlet. When devices are discovered or the search is complete,
events will be delivered to our MIDlet. Note that the startInquiry() method
returns immediately, returning true if the device discovery was initiated or false
if the device discovery process was not started. An event will be delivered to the
MIDlet when the device discovery is completed. This is important to take into
account when designing the flow of execution in the MIDlet.

The deviceDiscovered() and inquiryCompleted() methods are used to
catch events related to the device discovery process. When a device is discovered the
deviceDiscovered() method of the object this will be called. The parameter
remoteDevice will be the discovered device, it is up to us to decide what to do
with it. Note that we do not know how many devices will be discovered. A Vector
will therefore be an appropriate data structure to save discovered devices.

The inquiryCompleted() method is called when the inquiry ends. The status
code supplied in the parameter param should always be checked. The complete code
for device discovery follows:




public class yourMIDlet extends MIDlet implements CommandListener,
DiscoveryListener {


Vector devicesFound = null;


* a welcome screen.
* should call doDeviceDiscovery when
*/

}

}

}


}


devicesFound.addElement(remoteDevice);
}


/* We should give the user an alert based on the
* inquiry status code
*/


switch (param) {

case DiscoveryListener.INQUIRY_COMPLETED:

/* Inquiry completed normally, add appropriate code
* here
*/

break;

case DiscoveryListener.INQUIRY_ERROR:

// Error during inquiry, add appropriate code here.

break;

case DiscoveryListener.INQUIRY_TERMINATED:

/* Inquiry terminated by agent.cancelInquiry()
* Add appropriate code here.
*/

break;
}
}

}

}


try {

}



try {


}



}
}
}

Discovered devices are kept in the DevicesFound vector by adding them as they
are discovered. When our search ends, we check if everything went as expected and
can alert the user by adding appropriate code in our switch-statement.

5.3 Service search
After device discovery is completed it is time to find out which services are offered
by the discovered devices. This is accomplished by doing a service discovery on the
device of interest.

The servicesDiscovered() and serviceSearchCompleted() methods
must be implemented. They will handle the events occuring when services are found
or the service discovery completes. In addition, the doServiceSearch() method
has been added to show how a service discovery is initiated. This method will start a
service discovery on the RemoteDevice supplied as a parameter, and is called in
the inquiryCompleted() method.

The complete example Bluetooth MIDlet looks like this:

import javax.bluetooth.UUID;

public class YourMIDlet extends MIDlet implements CommandListener,
DiscoveryListener {


private Vector devicesFound = null;
private ServiceRecord[] servicesFound = null;



* a welcome screen.
* should call doDeviceDiscovery() when
*/

}

}

}


}


devicesFound.addElement(remoteDevice);
}


/* We should give the user an alert based on the
* inquiry status code
*/

switch (param) {


/* Inquiry completed normally, so we
* initiate a service discovery on the first
* device found. That is, if we actually
* found any devices.
*/

if (devicesFound.size() > 0){

doServiceSearch( (RemoteDevice)
devicesFound.firstElement());
}
break;


//Error during inquiry, add appropriate code here

break;



/*
* Inquiry terminated by agent.cancelInquiry()
* Add appropriate code here
*/

break;
}
}


/* Services discovered, keep reference to the ServiceRecord
* array
*/

servicesFound = serviceRecord;
}


switch(respCode) {

case DiscoveryListener.SERVICE_SEARCH_COMPLETED:

/*
* Service search completed successfully
*/

break;

case
DiscoveryListener.SERVICE_SEARCH_DEVICE_NOT_REACHABLE:

// device not reachable, add appropriate code here

break;

case DiscoveryListener.SERVICE_SEARCH_ERROR:

// Service search error, add appropriate code here

break;

case DiscoveryListener.SERVICE_SEARCH_NO_RECORDS:

// No records found, add appropriate code here

break;

case DiscoveryListener.SERVICE_SEARCH_TERMINATED:


/*
* Search terminated by agent.cancelServiceSearch()
*/

break;
}

}


try {

}



try {


}

}
}

private void doServiceSearch(RemoteDevice device) {

/*
* Service search will always give the default attributes:
* ServiceRecordHandle (0x0000), ServiceClassIDList (0x0001),
* ServiceRecordState (0x0002), ServiceID (0x0003) and
* ProtocolDescriptorList (0x004).
*
* We want additional attributes, ServiceName (0x100),
* ServiceDescription (0x101) and ProviderName (0x102).
*
* These hex-values must be supplied through an int array
*/

int[] attributes = {0x100,0x101,0x102};

/*
* Supplying UUIDs in an UUID array enables searching for
* specific services. PublicBrowseRoot (0x1002) is used in


* this example. This will return any services that are
* public browseable. When searching for a specific service,
* the service's UUID should be supplied here.
*/

UUID[] uuids = new UUID[1];
uuids[0] = new UUID(0x1002);

try {
agent.searchServices(attributes,uuids,device,this);
} catch (BluetoothStateException e) {

}
}
}

The searchServices() method will return immediately, returning a transaction
ID for the service discovery. The transaction ID is used to identify the particular
service discovery. When the service discovery completes, an event will be delivered
to the MIDlet.

This example Bluetooth MIDlet will hopefully be of help to J2ME application
developers getting started with Bluetooth programming. Study the Bluetooth Browser
source code in Appendix A to see what a fully functional Bluetooth MIDlet looks
like.

5.4 RFCOMM links with JABWT
After device discovery and service discovery are completed a client has all the
information needed to set up a communication link to a service on the server. L2CAP
links are the basis for all communication through JABWT. An L2CAP link can be set
up by supplying a "btl2cap://hostname:[PSM | UUID];parameters" type of URL as
parameter to the Connector.open() method. The PSM (Protocol/Service
Mulitplexer) value is similar in function to the port number of a traditional service on
an IP (Internet Protocol) network and is used by a client connecting to a server. The
UUID value is used when setting up a service on a server. Care must be taken by the
developer when using L2CAP links. The developer must keep track of the receive
MTU (Maximum Transfer Unit) and transmit MTU and divide data into chunks so
that data may be sent in packages with appropriate payload size. These concerns
increase the complexity of Bluetooth application development.

Fortunately, the Bluetooth Serial Port Profile (SPP) is implemented and available
through JABWT. The SPP is based on the RFCOMM protocol, providing RS-232
serial port emulation for Bluetooth links. The RFCOMM protocol is again based on
L2CAP, so it is actually an L2CAP link used for data transfer. Setting up an
RFCOMM connection is just as easy as setting up an L2CAP connection. The URL
supplied as parameter to the Connector.open() is of the form:


"btspp://hostname:[CN | UUID];parameters." The CN (Channel Number) value is
similar to the port number of a service on an IP network, and is used by a client
connecting to a server. The UUID value is used when setting up a service on a server.

RFCOMM takes care of all the important details, like receive MTU and transmit
MTU and dividing data into chunks so that the MTUs are not violated. RFCOMM
should therefore be the preferred link type for most developers.

5.4.1 RFCOMM server
When creating a custom Bluetooth service, it should be assigned a unique UUID. This
will ensure that clients do not confuse your service with other services. When creating
a custom Bluetooth service a 128-bit UUID must be created. This can be done very
easily on a Linux system. The uuidgen -t command will generate a 128-bit UUID
based on the current system time and the 48-bit hardware address of the system's NIC.
The 48-bit hardware address portion of the UUID will ensure that no one else will
generate the same UUID, assuming they are generating the UUID in a similar way.
The 80-bit portion of the UUID which is based on the system time will ensure that
two identical UUIDs are not generated on the same system, assuming that the system
time is not reset. Note that the uuidgen -t command will generate UUIDs with
the following format: f3d68400-b4c7-11d8-80a2-000bdb544cb1. JABWT does not
support UUIDs with hyphens, so if the sample UUID is to be used it must have the
following format: f3d68400b4c711d880a2000bdb544cb1. The UUID will be added
to the ServiceClassIDList attribute (attribute ID 0x0001) by the JABWT
implementation.

Setting up an RFCOMM server is fairly easy, as shown by the following code:

LocalDevice local = null;
StreamConnectionNotifier server = null;
StreamConnection conn = null;

String connectionURL =
"btspp://localhost:393a84ee7cd111d89527000bdb544cb1;"
+ "authenticate=false;encrypt=false;name=RFCOMM Server";

/*
* Make sure the device is discoverable, else clients cannot
* find our service
*/

try {
local.setDiscoverable(DiscoveryAgent.GIAC);



}

/*
* First get a StreamConnectionNotifier. It is used to get
* the service record created for us, so we can manipulate
* the service record.
*/

try {
server = (StreamConnectionNotifier)
Connector.open(connectionURL);
} catch (IOException e1) {


}

/*
* acceptAndOpen() will register the service record in the
* Bluetooth SDDB and block until a client connects.
*/

try {
conn = server.acceptAndOpen();


}

This is actually all the code needed to create a service record with UUID:
393a84ee7cd111d89527000bdb544cb1 and support for RFCOMM links. Additional
parameters have been specified, neither authentication or encryption are enforced.
Connection parameters are outlined in Section 5.4.3. The service will have service
name “RFCOMM Server,” this will be added in attribute ID 0x100 in the service
record. All other attributes are set automatic by the implementation. When a client
connects to the service, the server can obtain input and output streams from the
StreamConnection object conn and communication can begin. The Bluetooth
benchmark application in Appendix B shows what a complete JABWT server MIDlet
may look like.

5.4.2 RFCOMM client
Clients will typically do an inquiry and service discovery before connecting to a
server. The example service from Section 5.4.1 can be found by specifying
"393a84ee7cd111d89527000bdb544cb1" as the UUID to search for during service
discovery.

When the desired service is found, a connection can be created with very little effort:


/*
* The service we want to connect to has been found earlier
* (by service discovery) and the service record is
* referencedthrough the object named: service (of type
* ServiceRecord)
*/


/*
* The connection URL is extracted from the service record.
* Authentication and encryption is disabled. The client does
* not require to be the master of the connection (the false
* parameter)
*/

String connectionURL = service.getConnectionURL(
ServiceRecord.NOAUTHENTICATE_NOENCRYPT,
false);

/*
* A StreamConnection is obtained from the connection URL
*/

try {
conn = (StreamConnection) Connector.open(connectionURL);
} catch (IOException e) {

}

/*
* The conn object is now a working StreamConnection, from
* which input/output streams can be obtained, enabling
* communication.
*/

The sample code shows just how little code is needed to set up a client connection. To
see how this fits into a complete MIDlet you should have a look at the source code for
the benchmark MIDlets found in Appendix B.

5.4.3 RFCOMM connection parameters
Several parameters may be included in the connection URL when connecting to a
Bluetooth service or creating a Bluetooth service. Security settings are configured
with these parameters. Setting the ServiceName attribute and controlling master/slave
switches are also done with these parameters. The parameters are listed in Table 5.1
along with their values.


Name Valid values Client or server
authenticate true, false Both
encrypt true, false Both
authorize true, false Server
Name Any valid string Server
master true, false Both
Table 5.1 RFCOMM connection parameters

The authenticate, encrypt, and authorize parameters are related to security, see
Section 2.8. If these parameters are not included in the connection URL, they are
implicit set to false. Setting the authenticate parameter to true will force
authentication of the remote device before the connection is made. Encryption can
only be initiated if both devices have authenticated each other. Therefore, the
authentication parameter does not have to be set int the connection URL if the encrypt
parameter is set to true. The same applies to the authorize parameter, since
authorization also requires authentication. In the following server connection URL the
service name will be BTService, the remote device will be authenticated and
authorized, but the other parameters will be set to false:

"btspp://localhost:393a84ee7cd111d89527000bdb544cb1;authorize=true;name=
BTService"

If the sample service also required encryption and to be the master of the connection,
the connection URL would be:

"btspp://localhost:393a84ee7cd111d89527000bdb544cb1;encrypt=true;authorize=true
;name= BTService;master=true"

Clients can only use the authenticate, encrypt and master parameters. Usually clients
build their connection URLs with the getConnectionURL() method, which has
two parameters. One is the security settings and the other is the master setting.

Note that there are combinations of parameters that are invalid. Setting authenticate to
false and encrypt to true will give an error.


5.5 Service records and JABWT
This section describes how developers handle service records with the JABWT and is
closely related to Section 2.5 and partly based on [7, Sec. 7.3]. Service records are
fetched during service discovery in order to obtain detailed information about
particular services. When creating a Bluetooth service and making it available to the
world, developers may want to manipulate the service attributes manually in order to
give clients sufficient information about the service. Handling service records is not
trivial for the unexperienced developer. The examples provided in books on Java
Bluetooth programming and on the Internet are usually quite complex. This section
aims to explain service record usage in-depth and also provide code samples for
advanced service record usage. Only JABWT specific code is shown in the code
samples, not complete multi-threaded MIDlet structures. Hopefully, this will make it
easier for developers to understand the essentials of service record usage with
JABWT.

5.5.1 Retrieving information from service records with JABWT
Every service available on a Bluetooth device is described by a service record. A
Bluetooth device maintains service records for all its services in the SDDB. When a
client searches for services, the relevant service records from the SDDB are returned
to the client. The client may then explore the different attributes of the returned
records to find out more about each service. Note that in-depth knowledge about
service records is not necessary to start developing JABWT applications since the
JABWT implementation automatically creates basic service records for services.
However, creating customized service records requires knowledge about how data is
stored internally in service records. The Bluetooth Assigned Numbers document
available at the Bluetooth SIG website [14] is very useful when working with service
records. The BluetoothServiceRecordCanvas.java source file in Appendix C shows
how the most common service attributes are retrieved from service records.

Data types for service record attributes
Attributes contain different data types such as integers or string values. The data is
represented using a data element construct, as outlined in Section 2.5. JABWT
provides a DataElement class, which has a similar structure to the data element
construct described in the Bluetooth Specification. When fetching the value of a
specific attribute, a DataElement object is returned by JABWT. Detailed
information about service record attributes can be found in the Bluetooth specification
[13, p. 366]. See Table 2.2 for a list of common service attributes.

Default attributes
Some attributes are retrieved by default by JABWT when fetching a service record.
These default attributes are: the ServiceRecordHandle, ServiceClassIDList,


ServiceRecordState, ServiceID, and ProtocolDescriptorList.

The ServiceRecordHandle (attribute ID 0x0000) uniquely identifies the service record
in the SDDB. It is similar to a primary key in an ordinary database. This makes it
possible to run several instances of the same service.

The ServiceClassIDList (attribute ID 0x0001) is a list of the serviceclasses the service
belongs to.

The ServiceRecordState (attribute ID 0x0002) is a counter which is updated every
time the service record changes. This enables clients to confirm that a cached service
record is still valid.

The ServiceID (attribute ID 0x0003) is a 128-bit ID identifying a particular instance
of the service. This attribute is useful if the same service is described in more than
one SDP server.

The ProtocolDescriptorList (attribute ID 0x0004) is a list of protocols supported by
your service. If your service supports e.g. RFCOMM this attribute will contain both
L2CAP (0x0100) and RFCOMM (0x0003).

With these attributes in place a client has enough information to connect to a service.
The getConnectionURL() method available in the ServiceRecord class will
use the mandatory attributes to build a valid connection URL.

Optional attributes

In addition to the default attributes, several optional attributes may exist in the
retrieved service record. Three interesting attributes are the ServiceName (attribute ID
0x100), ServiceDescription (attribute ID 0x101) and ProviderName (attribute ID
0x102), which are represented as strings in DataElement objects. If they are
present in the service record they may be retrieved quite easily. The following
example shows how to retrieve the ServiceName attribute.

/*
* ServiceRecord sr is obtained during service discovery,
* now we just extract a value from it.
*/

String name = null;

DataElement elm = sr.getAttributeValue(0x100);

/*
* Always check for null here. If the attribute is not
* set, null will be returned. Also check the datatype


* set in the header of the DataElement to make sure that
* the DataElement really contains a string.
*/

if (elm != null && elm.getDataType() == DataElement.STRING) {
name = (String) elm.getValue();
}

To get the ServiceDescription or ProviderName attributes, just switch the hex value
attribute ID used in this example. This was a small and simple example. Look at the
source code in BluetoothServiceRecordCanvas.java in Appendix C to see how to
handle more complex attributes.

5.5.2 Manipulating service records with JABWT
When creating Bluetooth services the JABWT implementation will handle the
creation of basic service records automatically. However, developers may require
more control of the data contained in a service record. This section gives an
introduction to service record manipulation.

A server creates a Bluetooth service by calling the Connector.open() method
with a Bluetooth specific connection URL as parameter. The Connector.open()
method returns a StreamConnectionNotifier object, which in turn is used to
actually start the service. A service record is created automatically for the service and
is editable when the service record is created, but before the service is actually started.
The JABWT implementation will initialize the mandatory attributes of the service
record automatically. Only one optional attribute, the ServiceName attribute (attribute
ID 0x100), can be supplied in the connection URL. All other optional attributes must
be set manually. The Server.java source code in Appendix B shows how to set several
of the optional attributes.

Setting optional attributes
Service search can be done using the PublicBrowseRoot value (0x1002) and will then
reveal all services which are browseable. This way, searching for a specific service is
not required. Clients may instead find several available services during service
discovery. The PublicBrowseRoot value must be manually added to the
BrowseGroupList (attribute ID 0x1005) attribute in the service record created by the
JABWT implementation. The following code sample will show how to do this.

StreamConnectionNotifier server = null;
ServiceRecord sr = null;

String conURL =
"btspp://localhost:1b34b730983d11d8898d000bdb544cb1;"
+ "authenticate=false;encrypt=false;name=BTDemoApp";


/*
* When creating a StreamConnectionNotifier a service record
* will automatically be created for us, describing the new
* service. The service will have the Serial Port (0x1101)
* value in the ServiceClassIDList (id 0x0001) attribute. The
* service record will also have both the L2CAP (0x0100) and
* RFCOMM (0x0003) values in the ProtocolDescriptorList (id
* 0x0004) attribute. Other mandatory attributes will be set
* automatically by the JABWT implementation. The optional
* ServiceName (id 0x100) attribute will be set to the name
* parameter, "BTDemoApp" in this case.
*/

try {

server = (StreamConnectionNotifier)
Connector.open(conURL);



}

/*
* The automatically created service record can be obtained
* from the LocalDevice object, using the reference to the
* StreamConnectionNotifier.
*/

try {
sr = local.getRecord(server);
}
catch (IllegalArgumentException iae){


}

/*
* We create a new DataElement and set its content correctly.
*/

DataElement elm = null;

/*
* Setting public browse root in the browsegrouplist
* attribute. The BrowseGroupList (id 0x0005) attribute
* contains a DataElement sequence, which in turn contains
* DataElements with UUIDs. The DataElement sequence must be
* created before we can add DataElements to it.
*/

elm = new DataElement(DataElement.DATSEQ);
elm.addElement(new DataElement(


DataElement.UUID,new UUID(0x1002)));

/*
* The DataElement is now prepared. It must be added to the
* appropriate attribute ID, in this case the
* BrowseGroupList.
*/

sr.setAttributeValue(0x0005,elm);

/*
* Finally, the service record must be updated in our
* LocalDevice.
*/

try {
local.updateRecord(sr);
} catch (ServiceRegistrationException e3) {


}

/*
* The call to acceptAndOpen() will enter the service record
* in the device's Service Discovery DataBase (SDBB) and
* start the service. The service will then be browseable to
* clients.
*/


try {
}
catch (ServiceRegistrationException sre){


}
catch (IOException e2) {

}

/*
* At this point a client is connected. input and output
* streams can be obtained from the conn object,
* communication can begin.
*/

The sample code shows all the code needed to create a Bluetooth service and make it
public browseable. Note that there are some concerns when doing communication
with MIDlets. Communication should be done in a separate thread. This issue is not
discussed further in this section. The interested reader can find some valuable links


about threads on the website describing this thesis [30].

Other optional but useful attributes are the ServiceDescription (attribute ID 0x101)
and ServiceProviderName (attribute ID 0x102) attributes. How to set these attributes
is shown by the following code sample:


//Setting ServiceDescription
elm = new DataElement(DataElement.STRING,
"Bluetooth demo service");

record.setAttributeValue(0x101,elm);

//Setting ServiceProviderName
elm = null;
elm = new DataElement(DataElement.STRING,
"Demo provider name");


The samples provided here give an introduction to manipulation of service records.
Developers who wish to do more advanced modifications to service records should
consult the JABWT API available for download at the JSR-82 website [28].

5.6 Pitfalls
Care must be taken when developing Bluetooth MIDlets. A Java/Bluetooth
implementation is cutting edge technology and has its flaws. During development of
the sample Bluetooth MIDlets the experience was that not everything works as
expected. At the time of writing the following issues apply to the Nokia 6600 and
Sony Ericsson P900 smartphones.

5.6.1 RFCOMM flow control
When a RFCOMM link is set up and ready for use, it is expected that one should be
able to send some data from one device to another and shut down the link without
problems. It turns out that the link is shut down, possibly before the data is transfered.
Hence, one way communication is not reliable over RFCOMM links. Nasty
exceptions are thrown, like the "Symbian error = - 36" exception. This was discovered
during development of the benchmark program, when setting up a link, transferring
some data from device A to device B and then shutting down the link.

The solution to this problem is to transfer some amount of data from device A to
device B and then send a byte back from device B to device A before shutting down
the link. Note that the connection must flushed in order to send data.


Care must also be taken concerning the amount of data sent at once. It seems one of
the buffers in use in the 6600 and P900 smartphones is 512 bytes. When trying to
transfer more than 512 bytes at once, the receiver gets 512 bytes and then the
connection will freeze. Sending 512 bytes, flushing, sending 1 byte back, and flushing
works fine. The connection is then kept alive.

5.6.2 RFCOMM EOF
All streams have an end, they say. This is also the case for Bluetooth links. When
using an InputStream obtained from the StreamConnection object you
should get -1 when there is no more data in the stream. In the real world, this is not
the case. You get an exception, once again the "Symbian error = - 36" exception.

One way to work around this is by first of all send the number of bytes to transfer,
and then send the bytes. The other device will then know how much data it will
receive and can stop reading when all data is received, thus avoiding the exception.
Doing this is fairly easy, since a DataInputStream and DataOutputStream
can be obtained from the StreamConnection. Simply send an int with the
number of bytes you intend to transfer.

5.6.3 Removal of service records
Service records are added to the Bluetooth SDDB when you call the
acceptAndOpen() method on the StreamConnectionNotifier object. This
is a blocking operation and should therefore be done in a seperate thread. To remove
the Service record from the Bluetooth SDDB one must call the close() method on
the StreamConnectionNotifier. This is very important. If the MIDlet exits
without doing this, the service record will stay in the Bluetooth SDDB, despite the
fact that the MIDlet is dead. This may or may not have security implications, it has
not been investigated just how much damage one can do with a dangling service
record.

5.6.4 Populating service records
The ServiceRecord class provides a populateRecord() method. This
method should make the device go on the air to retrieve additional attributes from the
remote device's service record. When using this method it returned false every
time, indicating that it could not retreive any additional attributes. This did not make
sense since the device was able to retrieve these additional attributes during the initial
service discovery. The conclusion is: retrieve the attributes you want in the initial
service discovery. The populateRecord() method does not work as expected.


5.6.5 Inquiry with P900
The P900 discovers all nearby devices but the inquiryCompleted() method is
always called with INQUIRY_ERROR as parameter when the inquiry completes
normally. A possible explanation is that Sony Ericsson has swapped the
INQUIRY_ERROR and INQUIRY_COMPLETED values. This could not be tested
properly since it is not known how to force an error during inquiry.

5.6.6 ServiceRecordHandle format
An interesting issue was discovered during the development of the Bluetooth browser
application. The ServiceRecordHandle is 32-bit ID which uniquely identifies each
service record within an SDP server. Doing service discovery with Bluetooth tools
available for Linux, this handle would look like e.g. 0x10003. The JABWT
implementation reports the value 0x3000100 for the same service. This seems to be a
big-endian/low-endian problem. Both Nokia and Sony Ericsson have been asked to
comment on this issue. No response has been received at the time of writing.

65

6 Sample applications

During the work with this thesis two sample Bluetooth MIDlets were developed. It
was a logical approach to first investigate the device discovery and service discovery
related parts of JABWT. The result of this investigation was the Bluetooth browser
application. Next, Bluetooth links had to be explored so a Bluetooth benchmark
MIDlet was developed. This way, it could be investigated how Bluetooth links were
set up and what transfer rates they could provide. Both the Bluetooth browser and the
Bluetooth benchmark programs are available for download from the klings.org WAP
site [40]. Both sample applications depend on features from the KlingsLib library in
Appendix C. The KlingsLib library provides tools to format textual information so it
can be displayed correctly on screen, print the attributes of a service record, print
Bluetooth system properties, work with short and long UUIDs, and map short UUIDs
to the corresponding protocol, service class or profile name. In addition, constants for
all numbers in the Bluetooth Assigned Numbers document are provided. Interested
developers can download the source code for both applications and the KlingsLib
library from the author's website [30].

6.1 Bluetooth browser
The Bluetooth browser application can search for discoverable Bluetooth devices,
search for services on discovered devices and show the content of the most common
attributes used in service records. The screenshot in Figure 6.1 shows the screen users
will see when starting up the Bluetooth browser.

Figure 6.1 Cached/known
devices

66 Chapter 6 Sample applications

Cached and known devices is a list of devices stored by the BCC. The Bluetooth
browser has not yet been on the air, so this list will only contain devices seen in the
past. In this case there are no known devices. A device discovery process may be
initiated through the menu, as seen in Figure 6.2.

Figure 6.2 Initiating device
discovery

A device discovery will be started immediately when New Search is selected. The
Bluetooth browser will then show a list of discovered Bluetooth devices, as seen in
Figure 6.3. Initially this list is empty, but is populated as devices are discovered.

Figure 6.3 Device discovery in
progress

Only Bluetooth addresses will be shown in the list of discovered devices during the
device discovery process. The Bluetooth friendly name must be retrieved after a
device is discovered. The Bluetooth browser will retrieve friendly names for all
devices after device discovery is completed. The user will then be presented a screen
equivalent to the screenshot in Figure 6.4.

Chapter 6 Sample applications 67

Figure 6.4 Device discovery
completed

When device discovery is completed and Bluetooth friendly names are retrieved for
all available devices, the user may initiate a service discovery on a device by
selecting it from the list. When the service discovery completes, the user will be
shown a list of discovered services. Figure 6.5 shows the result from a service
discovery on the Sony Ericsson P900 smartphone.

Figure 6.5 Service search on
P900

The user may now select any of the services from the list in order to investigate that
service's attributes. Selecting the Bluetooth Serial Port service will reveal the
attributes shown in Figure 6.6.


Figure 6.6 Service attributes

Due to the limited screen size on the Nokia 6600, the user must scroll down to see the
rest of the attributes, shown in Figure 6.7.

Figure 6.7 Service attributes

The Bluetooth browser enables users to search for nearby discoverable Bluetooth
devices. In addition, a service discovery may be done on the discovered devices,
revealing all public browseable services. Each service may be examined in detail,
showing the most common service attributes.

6.2 Bluetooth benchmark
The Bluetooth benchmark applications enable users to test the throughput of
RFCOMM links between Java Bluetooth enabled devices using various amounts of
data. Security settings are demonstrated, users may request security features for a


Bluetooth link and verify if the request was fulfilled or not when the connection is
made.

The Bluetooth benchmark MIDlet suite contains two MIDlets, a server MIDlet and a
client MIDlet. The server MIDlets must be run on a discoverable Bluetooth device.
The client MIDlet will first do a device discovery, showing the user a list of nearby
devices. The user should then select a device from the list, initiating a service
discovery on that device. If the benchmark service is found, the client will
automatically connect to the service. The benchmark MIDlets use a RFCOMM link
for communication, due to the fact that most developers will prefer RFCOMM over
L2CAP. The benchmark MIDlets have a simple user interface. The reason for this is
to keep MIDlet activity to a minimum, so that as much resources as possible are
available for the communication. The highest possible transfer rate should then be
achieved.

Table 6.1 shows that the transfer rate achieved varies, depending on which devices
are involved in the transfer. These numbers are not affected when enabling or
disabling encryption on the Bluetooth link.

Devices Result
Nokia 6600 to Nokia 6600 10-11 KB/s
Nokia 6600 to Sony Ericsson P900 10-11 KB/s
PC to Nokia 6600 25 KB/s
Table 6.1 Benchmark results

In the PC-to-Nokia 6600 test, the benchmark MIDlet was run through the ME4SE
emulator [41], using the Rococo developer kit for Linux [32] to interact with the
Linux Bluez Bluetooth stack [42]. It is quite interesting that PC-to-smartphone
communication gives a higher transfer rate than smartphone-to-smartphone
communication. This means that the smartphones are not able to send data at the
same rate as the PC. Where the bottleneck is located is difficult to say, since the
details of how JABWT is implemented is not known.

6.2.1 Benchmark server
The benchmark server will create a Bluetooth service and make it available to nearby
Bluetooth devices. RFCOMM is used as the communication protocol. The user can
change security settings through the Settings menu and start the server. The
screenshot in Figure 6.8 shows the main menu in the benchmark server application.


Figure 6.8 Benchmark server
main menu

The user may change the settings for the connection through the Settings menu,

settings

The user has no option for the master parameter because the Nokia 6600 does not
support master/slave switches. However, security related parameters may be
configured by the user. When the settings are configured the user may start the server.
A service record will be created by JABWT and entered into the SDDB. Benchmark
clients may then find the service through the service discovery process and connect to
the service. The user is presented the screen seen in Figure 6.10 when the server is
started and is waiting for client connections.


started
The connection URL used to create the service is printed so the user can verify that
the settings are correct. The screen indicates that the server is waiting for client
connections. When a client connects to the service a paring process may be initiated
by the BCC if authentication is required. The BCC will query the user for a passkey if
necessary, or complete the authentication process without user interaction if the
devices are already paired. When the client is connected and data transfer
commences a screen equivalent to Figure 6.11 is shown.

Figure 6.11 Client connected to
server

The user will see details about the connected client and security settings for the
Bluetooth link, as reported by the BCC. When the transfer completes the user will get
a summary of how much data was sent and the elapsed time, as seen in Figure 6.12.


Figure 6.12 Benchmark server,
transfer results
The service can be restarted if the user wants to do another benchmark.

6.2.2 Benchmark client
The benchmark client is similar to the benchmark server. Device discovery and
service discovery must be done by the client before it can connect to the server. When
nearby devices have been discovered, the user may select a device from a list in order
to search for the benchmark service, as seen in Figure 6.13.

Figure 6.13 Benchmark client,
device discovery

If the selected device provides the benchmark service, the user will be notified and
may configure the settings for the connection through a Settings screen similar to the
one in the server application. A connection will be made and the data transfer will
commence when the user selects the amount of data to transfer from the screen


selection of data amount

To notify the user that the transfer is in progress, a status screen will be displayed.
Figure 6.15 shows that the user is presented details about the server and the security
settings for the connection.

transfer status screen

When the transfer is finished, the user is told how much data was transferred, as
shown in Figure 6.16. The server will display how much time elapsed during the data
transfer.


transfer finished

75

7 Summary and conclusions

7.1 Summary
This thesis has described and evaluated Bluetooth and J2ME technologies—helping
the reader understand the foundation for the JABWT technology. The Bluetooth
technology is advanced, and the large and complex specification makes it hard to get
a sufficient overview of the technology. The Bluetooth architecture was therefore
described in general, before important Bluetooth concepts such as device discovery,
service discovery, creation of services, and service record usage were discussed. The
Bluetooth security model was also explained since JABWT relies on security features
available in Bluetooth.

The reader was expected to be familiar with the J2ME technology. Still, an overview
of the J2ME technology was given so that readers with little or no knowledge of
J2ME could understand the architecture and investigate the technology further on
their own. References were included to J2ME resources, suitable as starting points for
further study of J2ME.

JABWT was described thoroughly. It was explained where JABWT has its place in
the J2ME architecture and how all important Bluetooth operations are done through
the API. Simple code samples were provided to show the structure of a Bluetooth
application and make it easier for the reader to understand how the JABWT actually
works. All key functionality: device discovery, service discovery, creating services,
connecting to services, customizing service records, and setting security parameters
for Bluetooth links were explained and documented through code samples. Additional
source code is included in the appendices, showing complete Bluetooth enabled J2ME
applications. Some noticeable bugs in JABWT implementations on current
smartphones were explained and workarounds were suggested. Developers aware of
these bugs can save a lot of time spent on debugging.

Infrastructure needed to develop JABWT applications was described. Available
development tools were discussed, giving the reader an overview of which tools are
available for Java Bluetooth development. It can be a time consuming task to both
find and test development tools. The reader can use the tools described in this thesis to
quickly start Java Bluetooth development.

Source code for sample applications using the JABWT functionality discussed in this
thesis is included in the appendices and is also available from the author's website
[30]. A separate library, KlingsLib, with J2ME and Java Bluetooth related tools was

76 Chapter 7 Summary and conclusions

developed during the work with this thesis. KlingsLib, its source code and JavaDoc
documentation are also available on the website. From the author's WAP pages [40],
the applications can be downloaded and installed to Java Bluetooth enabled
cellphones.

7.2 Conclusions
JABWT is cutting edge technology. After completing the work with this thesis it is
clear that JABWT implementations have some flaws and do not always work as
expected. Several of these flaws were investigated and described, and methods to
avoid these problems were given. At the time of writing, extra care must be taken by
Java Bluetooth developers when using JABWT due to the implementation flaws on
Java Bluetooth devices. It is expected that future implementations of JABWT will be
of better quality, JABWT will then provide a nice set of tools for developers working
with Java Bluetooth applications.

Much of the information in this thesis is also available on the author's website [30].
The traffic to this website has increased with the amount of Java Bluetooth
information published there. Now there are nearly 2000 unique visits each month to
these pages and several developer forums are linking to them. J2ME developers and
students around the world who are starting their work on the Java Bluetooth
technology contact the author for help. This confirms that the interest for the Java
Bluetooth technology is increasing, and that this thesis has a growing audience.

7.3 Further work
During the work with this thesis it was investigated how JABWT could and should be
used. Some of the JABWT functionality can be a bit complex for Java developers
with little knowledge of Bluetooth. Creating a new API that simplifies the use of
JABWT could be of interest. There was not enough time available to look at L2CAP
links, so investigating L2CAP links is also of interest.

Security is an important aspect of Java Bluetooth programming. It is of great interest
to study how the BCC relates to the Bluetooth security manager. Some irregularities
were found when using the security functions on the smartphones, studying these
issues further would be very valuable. Looking into how the Bluetooth security
manager is implemented on Bluetooth devices is also an exciting subject.

Investigating Bluetooth profiles, especially the Sim Access profile, would be
interesting since it can be used for small-amount payment solutions.

79

Appendix A BTBrowser

BTBrowserMIDlet.java
/*
* BTBrowserMIDlet.java
*
* Version 1.0
*
* 22. June 2004
*
* Copyright (c) 2004, Andre N. Klingsheim
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the NoWires research group nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/

package org.klings.j2me.BTBrowser;

import javax.microedition.midlet.*;
import javax.microedition.io.ConnectionNotFoundException;
import javax.microedition.lcdui.*;

import java.util.*;
import java.io.*;

import javax.bluetooth.*;
import org.klings.wireless.j2me.*;

80 BTBrowserMIDlet.java Appendix A

import org.klings.wireless.BluetoothNumbers.*;

public class BTBrowserMIDlet extends MIDlet implements CommandListener,

DiscoveryListener{

/* Reference to the Display object to do anything useful with UI*/
private Display display = null;

/* Reference to LocalDevice to do anything concerning Bluetooth */
private LocalDevice local=null;

/* Reference to a DiscoveryAgent to do inquiry or service searches */
private DiscoveryAgent agent=null;

/* Globally available Vectors for devices and services found */
private Vector deviceVector = null;
private Vector serviceVector = null;

/* Global Ticker used for most screens in this application */
private Ticker tic = null;

/*
* Global UI list accessible to deviceDiscovered(...) so we can
* show devices and services as they are discovered, giving the user a
* feeling of progress in the program
*/

private List deviceList = null;
private List serviceList = null;

private String clientExecutableURL = null;
private String documentationURL = null;

private BluetoothServiceRecordCanvas rCanvas = null;

/*
* Global list of interesting service attributes used when populating and
* showing service records
*/

int[] attrs = {
BTServiceAttributeId.SDP_SERVICENAME,
BTServiceAttributeId.SDP_SERVICEDESCRIPTION,
BTServiceAttributeId.SDP_PROVIDERNAME,
BTServiceAttributeId.SDP_SERVICEINFOTIMETOLIVE,
BTServiceAttributeId.SDP_SERVICEAVAILABILITY,
BTServiceAttributeId.SDP_BLUETOOTHPROFILEDESCRIPTORLIST,
BTServiceAttributeId.SDP_DOCUMENTATIONURL,
BTServiceAttributeId.SDP_CLIENTEEXECUTABLEURL,
BTServiceAttributeId.SDP_ICONURL,
};

/* Globally available commands used for most menus */

Command exitCommand = new Command("Exit",Command.EXIT,2);
Command searchCommand = new Command("New Search",Command.SCREEN, 1);

Appendix A BTBrowserMIDlet.java 81

Command backCommand = new Command("Back", Command.BACK, 1);
Command cancelCommand = new Command("Cancel",Command.CANCEL,1);
Command openURL = new Command("Open URL",Command.CANCEL,2);

/* Integer to keep track of which menu is active */
int currentMenu = 0;

/* Boolean stating if an inquriy is in progress or not */
boolean inquiring = false;

/*
* Integer to keep track of service searches. Needed to cancel an
* ongoing service search
*/
int serviceSearch = 0;


display = Display.getDisplay(this);

Alert a = null;
try {

a = new Alert("Bluetooth error",
"Either Bluetooth must be turned on, or your "+
"device does not support JABWT",
null,AlertType.ERROR);

a.setTimeout(Alert.FOREVER);
a.addCommand(exitCommand);
a.setCommandListener(this);
}

tic = new Ticker("By Klings, www.klings.org/nowires");
mainMenu(a);
}


display = null;
local=null;
//attrs = null;
tic = null;

}


notifyDestroyed();
}

/*
* mainMenu() will present the user a list of cached and preknown devices,
* and provide a menu to initiate device discovery (inquiry) in order to
* find nearby Bluetooth devices
*/


private void mainMenu(Alert a) {

List knownDevices = new List("Cached/known devices",List.IMPLICIT);

if (deviceVector == null) deviceVector = new Vector();
if (agent == null) agent = local.getDiscoveryAgent();

/* Retrieve PREKNOWN devices and add them to our Vector */

RemoteDevice[] devices = agent.retrieveDevices(
DiscoveryAgent.PREKNOWN);

String name = null;

if (devices != null) {

/*
* Synchronize on vector to obtain object lock before loop.
* Else, object lock will be obtained every iteration.
*/
synchronized(deviceVector) {

for (int i = devices.length-1;i >=0;i--) {
deviceVector.addElement(devices[i]);

try {
name = devices[i].getFriendlyName(false);

}catch (IOException ioe) {
name = devices[i].getBluetoothAddress();
}
if (name.equals(""))

knownDevices.insert(0,name,null);
}
} //End synchronized
}

/* Retrieve cached devices and add them to our Vector */

devices = null; devices = agent.retrieveDevices(
DiscoveryAgent.CACHED);

if (devices !=null) {


try {
}

knownDevices.insert(0,name,null);

}
}
}

/* Indicate to user if the Vector is empty */

if (deviceVector.isEmpty()) {
knownDevices.append("Empty",null);
}

knownDevices.setTicker(tic);
knownDevices.addCommand(exitCommand);
knownDevices.addCommand(searchCommand);
knownDevices.setCommandListener(this);

/* If we have an Alert, show it... */

if (a ==null ) display.setCurrent(knownDevices);
else display.setCurrent(a,knownDevices);

currentMenu = 1;

}

/*
* deviceScreen() will show the user a list of devices found
* during device discovery (inquiry)
*/
private void deviceScreen(Alert a) {

/*
* if currentmenu < 3 we are in screen with known/cached devices or
* screen with discovered devices and have issued a device search
* deviceList is then reinitialized by startInquiry(), hence we
* must add these commands again
*/

if (currentMenu < 3) {

deviceList.setTicker(tic);
if(inquiring ) {
deviceList.setTitle("Please wait...");
deviceList.addCommand(cancelCommand);

}else {
deviceList.setTitle("Devices:");
deviceList.removeCommand(cancelCommand);
deviceList.addCommand(exitCommand);
deviceList.addCommand(searchCommand);
deviceList.addCommand(backCommand);

}

deviceList.setCommandListener(this);
}

/* Display Alert if any... */


if (a == null) display.setCurrent(deviceList);
else display.setCurrent(a,deviceList);
currentMenu = 2;
}

/*
* startInquiry() will reinitialize the list of devices, and initiate
* a device discovery (inquiry) repopulating the list of devices
*/
private void startInquiry() {

Alert a = new Alert("Inquiry status",null,null,AlertType.INFO);

if (agent ==null) agent = local.getDiscoveryAgent();

/* Get rid of old search results in vector and deviceList */

deviceVector.removeAllElements();
deviceList = null; deviceList = new List("Devices",List.IMPLICIT);

/* Start the actual inquiry */

try {
inquiring = agent.startInquiry(DiscoveryAgent.GIAC, this);
a.setType(AlertType.ERROR);
a.setString("Bluetooth error while starting inquiry");
mainMenu(a);
return;
}

if (inquiring) {
a.setString("Inquiry started");
deviceScreen(a);
}
else {
a.setString("Error starting inquiry");

//With no Inquiry we have no need for this any more.
deviceList = null;
mainMenu(a);
}
}

/*
* getFriendlyNames() will contact all devices in the deviceVector and
* retrieve their friendly names, if available
*/
private void getFriendlyNames() {
String name = null;
for (int i = deviceVector.size() -1; i>= 0;i--) {

try {
name = ((RemoteDevice)
deviceVector.elementAt(i)).getFriendlyName(false);

/*


* An IOException may occur if the remote device can not be
* contacted or the remote device could not provide its name.
* In that case we leave the Bluetooth address in the list,
* and move on to the next device found.
*/
continue;
}

if (!name.equals("")) {
deviceList.set(i, name,null);
}
}

}

/*
* startServiceSearch() will initiate a service search on the supplied
* remote device.
*/
private void startServiceSearch(RemoteDevice rDevice) {

Alert a = null;

//Prepare serviceVector
if (serviceVector == null) serviceVector = new Vector();
else serviceVector.removeAllElements();

serviceList = null; serviceList = new List("",List.IMPLICIT);
try {
serviceList.setTitle( rDevice.getFriendlyName(false));
serviceList.setTitle(rDevice.getBluetoothAddress());
}

/*
* Search for services containing the PublicBrowseRoot UUID (0x1002)
* Should give us all public browseable services
*/

uuids[0] = new UUID(0x1002);

/*
* Start the actual service search, using the attrs array initialized
* earlier, the UUID array and the remote device we want to do a
* service search on
*/
try {
serviceSearch = agent.searchServices(attrs, uuids, rDevice, this);
a = new Alert("Bluetooth error", "Error starting service search",
null, AlertType.ERROR);
deviceScreen(a);
return;
}

a = new Alert("Status","Service search started. Please wait!",
null, AlertType.INFO);

deviceScreen(a);
}

/*
* serviceScreen() will present a list of discovered services to the user
*/
private void serviceScreen(Alert a) {

//Make sure we only add these commands once
if (currentMenu <= 2) {

serviceList.setTicker(tic);

if(serviceSearch == 0) {
serviceList.addCommand(exitCommand);
serviceList.addCommand(backCommand);
serviceList.removeCommand(cancelCommand);
}else{
serviceList.addCommand(cancelCommand);
}

serviceList.setCommandListener(this);
}

if (a == null) display.setCurrent(serviceList);
else display.setCurrent(a,serviceList);
currentMenu = 3;
}

/*
* showService() will create a recordCanvas showing service attributes
* to the user
*/
private void showService(int index) {

ServiceRecord s = (ServiceRecord) serviceVector.elementAt(index);
if (rCanvas == null){
rCanvas = new BluetoothServiceRecordCanvas(s);

rCanvas.addCommand(exitCommand);
rCanvas.addCommand(backCommand);
rCanvas.setCommandListener(this);
}else{

rCanvas.setServiceRecord(s);
rCanvas.removeCommand(openURL);

}

clientExecutableURL = rCanvas.getClientExecutableURL();
documentationURL = rCanvas.getDocumentationURL();

if (clientExecutableURL !=null || documentationURL != null)
rCanvas.addCommand(openURL);

//rCanvas.setTicker(tic);
display.setCurrent(rCanvas);
currentMenu = 4;


}

private void openURLScreen(){

List list = new List("Open URL",List.IMPLICIT);

list.append("Documentation",null);
list.append("Client Executable",null);
list.addCommand(backCommand);
list.setCommandListener(this);
currentMenu = 5;
}

private void openURL(String url){

boolean mustExit = false;
Alert a = new Alert("Error","",null,AlertType.ERROR);
try {
mustExit = platformRequest(url);
} catch (ConnectionNotFoundException e) {
a.setString("This device cannot open URLs requested by Java "+
"programs. See http://www.klings.org/nowires "+
"for information.");
display.setCurrent(a,rCanvas);
currentMenu = 4;
return;
}

if (mustExit){
a.setType(AlertType.INFO);
a.setTitle("Notification");
a.setString("The URL MAY be opened when this application exits."+
" Choose exit to open URL now.");
display.setCurrent(a,rCanvas);
currentMenu = 4;
}
}

/*
* deviceDiscovered() is called by the JABWT implementation when a device
* is discovered during device discovery (inquiry)
*/
public void deviceDiscovered(javax.bluetooth.RemoteDevice remoteDevice,
javax.bluetooth.DeviceClass deviceClass) {

//Add device to vector in case of further use
deviceVector.addElement(remoteDevice);

/* Add vector to active list, making devices show up as they are added
* Add only BT address, since getting the name requires going on air
* Will get friendly name later, device is probably quite busy now
*/
deviceList.append(remoteDevice.getBluetoothAddress(),null);

}

/*
* inquiryCompleted() is called by the JABWT implementation when device


* discovery (inquiry) is completed
*/
inquiring = false;
switch(param) {

/*
* If inquiry completed normally, give the user an alert stating
* that no devices were found, or the number of devices discovered.
* Also, retrive friendly names, if devices were discoverd.
*/

if (deviceVector.size() == 0) {
a.setString("No devices found!");
deviceList.append("Empty",null);
}else {
getFriendlyNames();
a.setString(deviceVector.size() + " devices found!");
}
deviceScreen(a);
break;

/*
* Alert the user if an error occured during device discovery
* (inquiry). Show list of devices found before error occured.
*/

if(deviceVector.size() > 0) {
a.setString("Error occured, but " + deviceVector.size()+
" devices found anyway!");
getFriendlyNames();
deviceScreen(a);
}
else{
a.setString("Error occured during inquiry.");
mainMenu(a);
}
break;

/*
* If the user requests termination of the device discovery
* (inquiry), alert the user that the process is actually
* terminated.
*/

a.setString("Search terminated");

getFriendlyNames();
deviceScreen(a);
}else{
mainMenu(a);
}

break;
}

}

/*
* servicesDiscovered() is called by the JABWT when services are discovered
* during service search. The transID parameter identifies the particular
* service search that returned results. The serviceRecord array is the
* services found during the search.
*/

DataElement nameElement = null;

synchronized(serviceVector) {

for (int i = 0;i < serviceRecord.length ; i++) {

nameElement = (DataElement)
serviceRecord[i].getAttributeValue(0x100);

if (nameElement != null
&& nameElement.getDataType() == DataElement.STRING) {
serviceList.append((String) nameElement.getValue(),null);
serviceVector.addElement(serviceRecord[i]);
}
}
}
}

/*
* serviceSearchCompleted() is called by the JABWT implementation when
* service search completes. the transID parameter identifies a particular
* service search, the responseCode indicates why the service search is
* ended.
*/
public void serviceSearchCompleted(int transID, int responseCode) {

/*
* serviceSearch is a handle to the active service search. Set this to
* 0 since the search is ended.
*/
serviceSearch = 0;

Alert a = new Alert("Search status",null,null,AlertType.INFO);

switch(responseCode) {

/*
* Service search completed normally. Show the user the results.
*/
a.setString("Service search complete");
serviceScreen(a);

break;


/*
* The remote device was not reachable, making it really hard to
* search for services.
*/
case DiscoveryListener.SERVICE_SEARCH_DEVICE_NOT_REACHABLE:

a.setString("Device not reachable");
deviceScreen(a);
break;

/*
* Some error occured during service search, alert the user.
*/
a.setString("Error during service search");
deviceScreen(a);
break;

/*
* No service were returned by the remote device, alert the user.
*/
a.setString("No services found");
deviceScreen(a);
break;

/*
* Service search termination requested by user, alert the user
* that the search is indeed terminated.
*/
deviceScreen(a);
break;
}

}

/*
* The commandAction() is the central nerve of a command-driven MIDlet.
* We must check wich command is selected and also keep track of which
* menu that was active when the command was selected. We make use of the
* currentMenu Integer to achieve this.
*/
public void commandAction(Command c,Displayable d) {

if (c == exitCommand) destroyApp(true);

else if(c == searchCommand) {
startInquiry();
}
else if(c == backCommand) {

/*
* User wants to go back, check where we are and fulfill


* the request.
*/
switch(currentMenu) {

case 2:
mainMenu(null);
break;

case 3:
deviceScreen(null);
break;

case 4:
serviceScreen(null);
break;

case 5:
display.setCurrent(rCanvas);
currentMenu = 4;
break;
}
}else if(c == cancelCommand){

/*
* The user wants to cancel either a device discovery or a service
* search. Check where we are, and fulfill the request.
*/

case 2:
if (inquiring) {
inquiring = !agent.cancelInquiry(this);
if (inquiring) {
deviceScreen(new Alert("Error",
"Could not stop inquiry or inquiry not started",
null, AlertType.ERROR));
return;
}
}else if (serviceSearch > 0
&& agent.cancelServiceSearch(serviceSearch)) {
deviceScreen(new Alert("Status",
"Service search terminated",null,
AlertType.INFO));
}

serviceSearch = 0;
break;

case 3:

if(!agent.cancelServiceSearch(serviceSearch)) {
serviceScreen(new Alert("Error",
"No active service search",null,
AlertType.ERROR));
}

break;


}
}else if (c == openURL){

openURLScreen();

}else if (c == List.SELECT_COMMAND) {

/*
* The user has selected something from a list. Find out where
* we are, get the List currently displayed and act according to
* this.
*/
List list = (List) display.getCurrent();
int index = list.getSelectedIndex();

switch (currentMenu) {

case 1: // Main list of known devices

case 2: //List of newly found devices
if (serviceSearch == 0 && ! deviceVector.isEmpty())
startServiceSearch(
(RemoteDevice)deviceVector.elementAt(index));
break;

case 3: //Browse service
if(! serviceVector.isEmpty()) showService(index);

break;

case 5: //The user wants to open an URL

switch(index){
case 0:
openURL(documentationURL);
break;

case 1:

openURL(clientExecutableURL);
break;

}

}//End switch for list-index
}// End if for List-command

}//End commandaction

}//End all

93

Appendix B BTBenchmark

Server.java
/*
* Server.java
*
* Version 1.0
*
* 22. June 2004
*
*
*
*
*
*
*/

package org.klings.wireless.j2me.BTBenchmark;

import javax.microedition.midlet.MIDletStateChangeException;
import javax.microedition.io.*;
import java.io.*;

public class Server extends MIDlet implements CommandListener, Runnable{

94 Server.java Appendix B

/* Display and Bluetooth LocalDevice */

private List list = null;

/* Commands */
private Command exitCommand = new Command("Exit",Command.EXIT,2);
private Command startCommand = new Command("Start",Command.SCREEN,2);
private Command settingsCommand = new Command("Settings",Command.SCREEN,2);
private Command backCommand = new Command("Back", Command.BACK, 1);
private Command btInfoCommand = new Command("BTInfo",Command.SCREEN,2);

/* Notifier for client connections */
private StreamConnectionNotifier server = null;

/* Connection for communication */
private StreamConnection conn = null;
private InputStream in = null;
private OutputStream out = null;

/* Connection parameters */
private boolean authenticate = false;
private boolean encrypt = false;
private boolean authorize = false;
private boolean master = false;

/* Canvas to show status to user */
private StatusCanvas s=null;

/* Initialized in createService(), defined globally so it is accessible
* by the communicating thread.
*/
private String connectionURL;

/* Thread for blocking functionality */

private Thread t = null;

/* Default constructor */
public Server() {
super();

}

protected void startApp() throws MIDletStateChangeException {



mainMenu(null);
}

protected void pauseApp() {
tic = null;
}

Appendix B Server.java 95

protected void destroyApp(boolean arg0) throws MIDletStateChangeException {

/*
* Ensure that cleanUp() is called before MIDlet exits. cleanUp()
* will close the notifier, which will remove the service record from
* device Bluetooth SDDB. Very important!
*/

cleanup();

/*
* If the communication Thread is waiting for clients, an exception
* occurs when we close the notifier. The thread will terminate,
* wait for it to terminate.
*/
if(t!=null){
try {
t.join();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

notifyDestroyed();
}
public void commandAction(Command c, Displayable arg1) {

if (c == exitCommand) {

try {
destroyApp(true);
} catch (MIDletStateChangeException e) {

}
}
else if(c == startCommand){

/*
* Start a server thread. createService() returns true
* if the service was created successfully.
*/

if (createService()){

/* Show status screen to user */
s = new StatusCanvas();
s.waitForClient(connectionURL);
s.addCommand(exitCommand);
s.setCommandListener(this);
s.setTicker(tic);
display.setCurrent(s);

t = new Thread(this);
t.start();

}else{
mainMenu(new Alert("Error","Error creating service",null,
AlertType.ERROR));


}

}else if(c == settingsCommand){

settings();
}else if (c == backCommand){

mainMenu(null);
}else if (c == btInfoCommand){

BluetoothInfoCanvas btic = new BluetoothInfoCanvas();
btic.addCommand(backCommand);
btic.setCommandListener(this);
display.setCurrent(btic);

}else if (c == List.SELECT_COMMAND) {

/* There is only one list. Check what the user selected */


switch (index){

case 0:

authenticate = !authenticate;
if(!authenticate) {
encrypt = false;
authorize = false;
}
break;

case 1:
encrypt = !encrypt;
if(encrypt) authenticate = true;
break;

case 2:

authorize = !authorize;
if (authorize) authenticate = true;
break;

case 3:

master = !master;
break;
}

/* Update settings screen so it reflects the user's choice */
settings();
}

}

/* Display list of connection settings */
private void settings() {


List sett = new List("Settings:",List.IMPLICIT);

sett.append("Authenticate: " + (authenticate?"On":"Off"),null);
sett.append("Encrypt: " + (encrypt?"On":"Off"),null);
sett.append("Authorize: " + (authorize?"On":"Off"),null);

if ("true".equals(LocalDevice.getProperty("bluetooth.master.switch")))
sett.append("Master: " + (master?"Yes":"No"),null);

sett.addCommand(startCommand);
sett.setCommandListener(this);

display.setCurrent(sett);
}

/* Display main menu */
private void mainMenu(Alert a){

list = new List("Benchmark Server",List.IMPLICIT);
list.setTicker(tic);
list.addCommand(exitCommand);
list.addCommand(startCommand);
list.addCommand(settingsCommand);
list.addCommand(btInfoCommand);
list.setCommandListener(this);

if(a == null){
display.setCurrent(list);
}else display.setCurrent(a,list);
}

/* Create ServiceRecord, set desired attributes */
private boolean createService(){

ServiceRecord record = null;


/* Get the Bluetooth LocalDevice */
try {
local.setDiscoverable(DiscoveryAgent.GIAC);
a.setString("Error getting localdevice or setting discovery mode");
display.setCurrent(a,list);
e.printStackTrace();
return false;
}

String param ="";

/* Add parameters to connection URL */
if(encrypt) param = "encrypt=true;";
else if(authorize) param="authorize=true;";
else if(authenticate) param="authenticate=true;";


param += "name=BTBench";

if(master) param +=";master=true";

connectionURL = "btspp://localhost:66ca80886d1f11d88526000bdb544cb1;"
+ param;

/* Get the notifier, will also generate a ServiceRecord */
try {
server = (StreamConnectionNotifier) Connector.open(connectionURL);

return false;
}

/* Get the ServiceRecord associated with the notifier */
try {
record = local.getRecord(server);
}
catch (IllegalArgumentException iae){
return false;

}

/*
* Manipulate the ServiceRecord to meet our needs. Some code is
* disabled, but is included to show how attributes are set.
*/

/*
* Set public browse root in browsegrouplist, making service
* public browseable
*/
elm = new DataElement(DataElement.DATSEQ);
elm.addElement(new DataElement(DataElement.UUID,new UUID(0x1002)));

/* Set service description */
elm = new DataElement(DataElement.STRING,"BT Benchmark service");

/* Set service provider name */
elm = new DataElement(
DataElement.STRING,"Klings, NoWires Research Group");

/* Set serviceInfoTimeToLive */
/*elm = new DataElement(DataElement.U_INT_4,10000);
record.setAttributeValue(0x0007,elm);*/

/* Set serviceAvailability */
/*elm = new DataElement(DataElement.U_INT_1,255);
record.setAttributeValue(0x0008,elm);*/

/* Set documentationURL */


DataElement.URL,"http://wap.klings.org/btbenchmark.wml");
record.setAttributeValue(0x000A,elm);

/* Set clientExecutableURL */

DataElement.URL,"http://wap.klings.org/java/btbenchmark.jad");
record.setAttributeValue(0x000B,elm);

/* Set iconURL */
/*elm = new DataElement(
* DataElement.URL,"http://klings.org/java/BTBenchmark.ico");
record.setAttributeValue(0x000C,elm);*/

/* Update the record, else changes are lost */
try {
local.updateRecord(record);
} catch (ServiceRegistrationException e3) {

return false;

}
return true;
}

/* run() method executed by communication thread */
public void run() {

/*
* If the notifier is not available, a service has not been
* created.
*/
if(server == null) return;


/*
* Open the notifier. This is a blocking operation. Now the
* ServiceRecord will be entered in the Bluetooth SDDB and
* the server is ready for client connections.
*/
try {
}
catch (ServiceRegistrationException sre){
a.setString("Error creating service record");

cleanup();
return;
}
catch (IOException e2) {
if (t != null){
a.setString("Error starting server. " + e2.getMessage());
}


cleanup();
return;
}

/* A client has connected! Retrieve information about the
* remote device and display it to the user.
*/
RemoteDevice dev = null;
String name,address;
boolean authorized = false;

try {
dev = RemoteDevice.getRemoteDevice(conn);
name = dev.getFriendlyName(false);
address = dev.getBluetoothAddress();
authorized = dev.isAuthorized(conn);
name = "Unknown";
address = "Unknown";
}

s.connectedToClient(name,address,dev.isAuthenticated(),
dev.isEncrypted(),authorized);

/*
* The user now knows who connected. Get streams and start
* communication.
*/
try {
in = conn.openInputStream();
out = conn.openOutputStream();
a.setString("Error opening input/output streams:" +
e4.getMessage());

cleanup();
t = null;
return;
}

DataInputStream dais = new DataInputStream(in);

byte[] data = new byte[512];

//int data;
long timer = 0;
boolean keepOn = true;
int bytesRead = 0;
int iterations = 0;

/* read the number of iterations */
try {
iterations = dais.readInt();
}catch (EOFException eof ){

a.setString("EOF on first read.");



cleanup();
return;
a.setString("Error on first read.");

cleanup();
return;
}

/* Get the time and do actual communication */
try{
timer = System.currentTimeMillis();

for (int i = iterations; i>0;i--){

bytesRead = dais.read(data,0,data.length);
out.write(0);
out.flush();
}
timer = System.currentTimeMillis() - timer;

a.setString(bytesRead +
" bytes read before communication error occured. " +
ioe.getMessage());

cleanup();
return;
}

/* Communication complete. Cleanup connections */
cleanup();
long sec = timer / 1000;
long transferred = iterations/2;

/* Display statistics to user */
a.setTitle("Success!");
a.setString("Read " + transferred +" KB in " + sec + " seconds.n"
+transferred/sec + " KBps");

list.addCommand(settingsCommand);
list.setTitle("Run complete.");

}


/* Close streams and notifier */
private void cleanup() {

try {

if(in != null){
in.close();
}

if(out != null){
out.close();
}

if (conn != null) {
conn.close();
}

if (server != null){

server.close();
}
}catch (IOException ioe){

// Error occurred.
}
}

}

Appendix B Client.java 103

Client.java
/*
* Client.java
*
* Version 1.0
*
* 22. June 2004
*
*
*
*
*
*
*/

import java.util.*;
import java.io.*;

import javax.microedition.io.*;


public class Client extends MIDlet implements CommandListener,
DiscoveryListener,
Runnable{

private LocalDevice local=null;
private DiscoveryAgent agent=null;

104 Client.java Appendix B

/* Vectors to store devices an services in */
private Vector deviceVector = null;
private Vector serviceVector = null;


/* Global list accessible to deviceDiscovered(...) */
private List deviceList = null;
private List serviceList = null;

/* lobal serviceRecord accessible to several threads */
private ServiceRecord globalRecord = null;

private StreamConnection conn = null;
private DataOutputStream out = null;
private InputStream in = null;

/* Connection parameters */
boolean authenticate,encrypt,master=false;

private int iterations = 0;

private Command exitCommand = new Command("Exit",Command.EXIT,2);
private Command searchCommand = new Command("New Search",Command.SCREEN, 1);
private Command backCommand = new Command("Back", Command.BACK, 1);
private Command cancelCommand = new Command("Cancel",Command.CANCEL,1);
private Command settingsCommand = new Command("Settings",Command.SCREEN,1);
private Command btInfoCommand = new Command("BTInfo",Command.SCREEN,2);

int currentMenu = 0;

/* Keep track of ongoing device discoveries */
boolean inquiring = false;

/* Keep track of ongoing service discoveries */
int serviceSearch = 0;



try {

System.err.println("LocalDevice error");
}

mainMenu(null);
}

display = null;
local = null;
tic = null;
}



cleanUp();

notifyDestroyed();
}

/* Main menu, list of cached/known Bluetooth devices */
private void mainMenu(Alert a) {

List knownDevices = new List("Cached/known devices",List.IMPLICIT);

if (deviceVector == null) deviceVector = new Vector();
if (agent == null) agent = local.getDiscoveryAgent();

RemoteDevice[] devices = agent.retrieveDevices(
DiscoveryAgent.PREKNOWN);

String name = null;

if (devices != null) {

/*
* Synchronize on vector before running through loop, since
* Vector methods are thread safe. We obtain the object lock
* on the Vector once, instead of every iteration. Add devices
* to the deviceVector.
*/


try {

}

knownDevices.append(name,null);
}
} //End synchronized
}
devices = agent.retrieveDevices(DiscoveryAgent.CACHED);

if (devices !=null) {


try {

}

knownDevices.append(name,null);
}
}
}

/* No cached/known devices, notify the user */
if (deviceVector.isEmpty()) {
knownDevices.append("Empty",null);
}

knownDevices.setTicker(tic);
knownDevices.addCommand(exitCommand);
knownDevices.addCommand(searchCommand);
knownDevices.addCommand(btInfoCommand);
knownDevices.setCommandListener(this);

/* Show Alert, if available */
if (a ==null ) display.setCurrent(knownDevices);
else display.setCurrent(a,knownDevices);

currentMenu = 1;

}

/* Show list of discovered devices */
private void deviceScreen(Alert a) {

/* if currentmenu < 3 we are in screen with known/cached devices or
* screen with discovered devices and have issued a device search
* deviceList is then reInitialized by startInquiry(), hence we
* must add these commands again
*/
if (currentMenu < 3) {

deviceList.setTicker(tic);
if(inquiring) {
deviceList.addCommand(cancelCommand);
}else{
deviceList.removeCommand(cancelCommand);
deviceList.addCommand(exitCommand);
deviceList.addCommand(searchCommand);
deviceList.addCommand(backCommand);

}

deviceList.setCommandListener(this);
}

if (a == null) display.setCurrent(deviceList);
else display.setCurrent(a,deviceList);
currentMenu = 2;
}

/* Start device discovery */


private void startInquiry() {


if (agent ==null) agent = local.getDiscoveryAgent();

/* Remove old search results in vector and deviceList */
deviceVector.removeAllElements();
deviceList = new List("Nearby devices",List.IMPLICIT);

/* Start the actual device discovery */
try {
inquiring = agent.startInquiry(DiscoveryAgent.GIAC, this);
a.setString("Bluetooth error while starting inquiry");
mainMenu(a);
return;
}

/* Notify the user if inquiry was started or not */
if (inquiring) {
a.setString("Inquiry started");
deviceScreen(a);
}
else {
a.setString("Error starting inquiry");

/* With no Inquiry we have no need for this any more. */
deviceList = null;
mainMenu(a);
}
}

/* Retrieve friendly names for all devices in deviceVector */
private void getFriendlyNames() {
String name = null;

synchronized(deviceVector){
for (int i = deviceVector.size() -1; i>= 0;i--) {

try {
name = ( (RemoteDevice)
deviceVector.elementAt(i)).getFriendlyName(false);
continue;
}
if (!name.equals("")) {
deviceList.set(i, name,null);
}
}// End for
}// End synchronized

}

/* Start service discovery on remote device */
private void startServiceDiscovery(RemoteDevice rDevice) {


Alert a = null;

/* Prepare serviceVector and service list*/
if (serviceVector == null) serviceVector = new Vector();
else serviceVector.removeAllElements();

serviceList = new List("",List.IMPLICIT);
try {
serviceList.setTitle( rDevice.getFriendlyName(false));
serviceList.setTitle(rDevice.getBluetoothAddress());
}


/* Add the BTBenchmark UUID to an array */
uuids[0] = new UUID("66ca80886d1f11d88526000bdb544cb1",false);

/*
* Retrieve default attributes, services with BTBenchmark UUID on
* the remote device.
*/
try {
int transid = agent.searchServices(null, uuids, rDevice, this);
a = new Alert("Bluetooth error", "Error starting service search",
null, AlertType.ERROR);
deviceScreen(a);
return;
}

}

/* Select amount of data to transfer */
private void selectDataScreen(Alert a) {

List tList = new List("Select amount of data ",List.IMPLICIT);
tList.append("10KB",null);

tList.addCommand(settingsCommand);
tList.addCommand(backCommand);
tList.setCommandListener(this);

if (a == null) display.setCurrent(tList);
else display.setCurrent(a,tList);
currentMenu = 3;
}

/*
* Set the number of iterations to use by the thread when communicating,
* then start the communication Thread.
*/
private void doTransfer(int index) {

switch(index){


case 0: iterations = 20; break;
}

Thread t = new Thread(this);
t.start();

}

/* Display settings menu */
private void settingsScreen(){

List settings = new List("Settings",List.IMPLICIT);
settings.append("Authenticate: " + (authenticate? "Yes":"No"),null);
settings.append("Encrypt: " + (encrypt? "Yes":"No"),null);

if ("true".equals(LocalDevice.getProperty("bluetooth.master.switch")))
settings.append("Master: " + (master? "Yes":"No"),null);

settings.addCommand(backCommand);
settings.setCommandListener(this);
display.setCurrent(settings);
currentMenu = 31;

}

/* A device is discovered. Add it to the deviceVector */
public void deviceDiscovered(javax.bluetooth.RemoteDevice remoteDevice,
javax.bluetooth.DeviceClass deviceClass) {

/* Add device to vector in case of further use */
deviceVector.addElement(remoteDevice);

/*
* Add device to active list, making devices show up as they are
* discoverd. Add only BT address, getting the name requires the
* device to go on air and the device is probably quite busy now.
*/

deviceList.append(remoteDevice.getBluetoothAddress(),null);

}

/* Device discovery completed. Get friendly names. */
public void inquiryCompleted(int status) {
inquiring = false;

/* Check status */
switch(status) {


if (deviceVector.size() == 0) {
a.setString("No devices found!");
deviceList.append("Empty",null);


}else {
getFriendlyNames();
a.setString(deviceVector.size() + " devices found!");
}
deviceScreen(a);
break;

a.setString("Error occured.");
mainMenu(a);
break;



getFriendlyNames();
deviceScreen(a);
}else{
mainMenu(a);
}
break;
}

}

/* ServiceSearch completed. */
serviceSearch = 0;
Alert a = new Alert("Search status",null,null,AlertType.INFO);

/* Check resonse Code */
switch(respCode) {

a.setString("Service found!");
selectDataScreen(a);

break;

case DiscoveryListener.SERVICE_SEARCH_DEVICE_NOT_REACHABLE:

a.setString("Device not reachable");
deviceScreen(a);
break;

a.setString("Error during service search");
deviceScreen(a);
break;

a.setString("No services found");
deviceScreen(a);
break;


deviceScreen(a);
break;
}

}

/* Services were discovered. */

DataElement nameElement = null;
String name = null;
RemoteDevice dev = serviceRecord[0].getHostDevice();

/*
* Keep the discovered service record in globalRecord so it is
* available to the communication thread.
*/
globalRecord=serviceRecord[0];

}

/* Command handler */
public void commandAction(Command c,Displayable d) {

if (c == exitCommand) destroyApp(true);

else if(c == searchCommand) {
startInquiry();
}
else if(c == backCommand) {

case 11:
case 2:
mainMenu(null);
break;

case 3:
deviceScreen(null);
break;

case 31:
case 4:
selectDataScreen(null);
break;

}
}else if(c == cancelCommand){


case 2: // Device discovery in progress
if (agent.cancelInquiry(this)) {

inquiring = false;


deviceScreen(null);

}else{
deviceScreen(new Alert("Error",
"Could not stop inquiry or inquiry not started",
null, AlertType.ERROR));
inquiring = false;
}

break;

case 3: //Service discovery in progress

if(!agent.cancelServiceSearch(serviceSearch)) {
selectDataScreen(new Alert("Error",
"No active service search",null,
AlertType.ERROR));
}

break;

}
}else if(c == settingsCommand){

settingsScreen();

}else if (c == btInfoCommand){
BluetoothInfoCanvas canv = new BluetoothInfoCanvas();
canv.addCommand(backCommand);
canv.setCommandListener(this);
display.setCurrent(canv);
currentMenu = 11;
}
else if (c == List.SELECT_COMMAND) {


switch (currentMenu) {

case 1: // Main list of known devices

case 2: //List of newly found devices
if (! deviceVector.isEmpty())
startServiceDiscovery( (RemoteDevice)
deviceVector.elementAt(index));
break;

case 3: //Browse service

doTransfer(index);

break;

case 31: //Settings changed

switch(index){


case 0:

authenticate = !authenticate;
if(!authenticate) encrypt = false;
break;

case 1:
encrypt = !encrypt;
if(encrypt) authenticate=true;
break;

case 2:
master = !master;
break;
}

settingsScreen();
break;
}//End switch for list-index
}// End if for List-command

}//End commandaction

/* Code executed by the communication thread */
public void run() {

/* Generate connection URL based on user selections */
String conURL = null;

if(encrypt){
conURL = globalRecord.getConnectionURL(
ServiceRecord.AUTHENTICATE_ENCRYPT,master);
}else if (authenticate){

ServiceRecord.AUTHENTICATE_NOENCRYPT,master);
}else{
ServiceRecord.NOAUTHENTICATE_NOENCRYPT,master);
}


Alert a = new Alert("Error",conURL,null,AlertType.ERROR);

/* Connect to the Benchmark server */
try {
conn = (StreamConnection) Connector.open(conURL);
a.setString("Error creating connectionn URL used:n"+conURL);
deviceScreen(a);
cleanUp();
return;
}

/* Display information about the server */
StatusCanvas s = new StatusCanvas();


RemoteDevice dev = globalRecord.getHostDevice();
String name = "Unknown";
try {
name = dev.getFriendlyName(false);
name = "Unretrievable";
}

s.connectedToServer(name,dev.getBluetoothAddress(),
dev.isAuthenticated(),dev.isEncrypted());

/* Open streams */
try {
out = conn.openDataOutputStream();
in = conn.openInputStream();
a.setString("Error opening streams");
display.setCurrent(a,serviceList);
cleanUp();
return;
}

/* Write the number of iterations */
byte[] bytes = new byte[512];
try {
out.writeInt(iterations);
out.flush();
a.setString("Error doing first write");
cleanUp();
return;
}

/* Send the actual data */
try {

for (int i = iterations; i > 0; i--){

out.write(bytes);
out.flush();
in.read();
}
a.setString("Error writing main load");
cleanUp();
return;
}

/* Clean up streams and connection */
cleanUp();

/* Display the number of KB sent */
a.setString("Sent " + iterations/2 + " KB. All well!");
a.setTitle("Done!");


deviceScreen(a);
}

/* Close streams and streamconnection */
private void cleanUp(){

try {
if (out != null){
out.close();
}

if (in != null){
in.close();
}

if(conn != null){
conn.close();
}
// Error occurred
}
}
}

116 StatusCanvas.java Appendix B

StatusCanvas.java
/*
* StatusCanvas.java
*
* Version 1.0
*
* 22. June 2004
*
*
*
*
*
*
*/


public class StatusCanvas extends Canvas{

private final int WAITING_FOR_CLIENT = 1;
private final int CONNECTED_TO_CLIENT = 2;
private final int CONNECTED_TO_SERVER = 3;

/* Anchor for text */
private final int ANCHOR = Graphics.LEFT|Graphics.TOP;

/* indent */
private final int X = 2;

private int mode = 0;
private boolean authentication,encryption,authorization,isServer;

Appendix B StatusCanvas.java 117

/* Different fonts for different types of text */
private Font plain,bold;

/*Size of canvas */
private int canvasHeight, canvasWidth;

/* Height of fonts */
private int plainHeight,boldHeight;

/* Keep track of where we are in the canvas */
private int y = 0;

/* Custom String */
private String remoteName,remoteAddress,connectionURL;

public StatusCanvas() {

super();

/*Get the canvas size */
canvasHeight = this.getHeight();
canvasWidth = this.getWidth();

/* Get height of fonts */
plain = Font.getFont(Font.FACE_SYSTEM, Font.STYLE_PLAIN,
Font.SIZE_MEDIUM);
bold = Font.getFont(Font.FACE_SYSTEM, Font.STYLE_BOLD,
Font.SIZE_MEDIUM);

/* heights to compute where to draw. */
plainHeight = plain.getHeight();
boldHeight = bold.getHeight();

/*Set Custom to null */
remoteName = null;
remoteAddress = null;
connectionURL = null;

}

protected void paint(Graphics g) {

/* Initialize the canvas */
g.setColor(0xffffff);
g.fillRect(0,0, getWidth(),getHeight());

/* We want black text */
g.setColor(0x000000);
g.setFont(plain);

if (isServer) serverStatus(g);
else clientStatus(g);

}

public void waitForClient(String connectionURL){

118 StatusCanvas.java Appendix B

/* this must be a server */
isServer = true;
mode = WAITING_FOR_CLIENT;
this.connectionURL = connectionURL;
this.repaint();
}

public void connectedToClient(String deviceName, String deviceAddress,
boolean authentication,boolean encryption,boolean authorization){

/* this must be a server */
isServer = true;
remoteName = deviceName;
remoteAddress = deviceAddress;
this.authentication = authentication;
this.encryption = encryption;
this.authorization = authorization;
mode = CONNECTED_TO_CLIENT;
this.repaint();
}
public void connectedToServer(String deviceName, String deviceAddress,
boolean authentication,boolean encryption){
/* this must be a client */
isServer = false;
remoteName = deviceName;
remoteAddress = deviceAddress;
this.authentication = authentication;
this.encryption = encryption;

mode = CONNECTED_TO_SERVER;
this.repaint();
}

private void serverStatus(Graphics g){

switch (mode){

case WAITING_FOR_CLIENT:
this.setTitle("Service started!");
y = 2;

y+= CanvasHelper.printString("Connection URL:",X,y,ANCHOR,
bold,canvasWidth-X,g);

y+= CanvasHelper.printString(connectionURL,X,y,ANCHOR,
plain,canvasWidth-X,g);

y+=plainHeight;

y+=CanvasHelper.printString("Waiting for client connection.",
X,y,ANCHOR,plain,canvasWidth-X,g);

break;

case CONNECTED_TO_CLIENT:
this.setTitle("Client connected!");
y = 2;

Appendix B StatusCanvas.java 119

y+= CanvasHelper.printString("Client name:",X,y,ANCHOR,
y+= CanvasHelper.printString(remoteName,X,y,ANCHOR,

y+= CanvasHelper.printString("Client address:",X,y,ANCHOR,
y+= CanvasHelper.printString(remoteAddress,X,y,ANCHOR,

y+= CanvasHelper.printString("Security settings:",X,y,ANCHOR,
y+= CanvasHelper.printString("Authenticated: " +
(authentication ? "Yes" : "No"),X,y,ANCHOR,
y+= CanvasHelper.printString("Encrypted: "+
(encryption ? "Yes" : "No"),X,y,ANCHOR,
y+= CanvasHelper.printString("Authorized: " +
(authorization ? "Yes" : "No"),X,y,ANCHOR,

break;

}

}

private void clientStatus(Graphics g){

if (mode == CONNECTED_TO_SERVER){

this.setTitle("Connected to server!");
y = 2;

y+= CanvasHelper.printString("Server name:",X,y,ANCHOR,
y+= CanvasHelper.printString(remoteName,X,y,ANCHOR,

y+= CanvasHelper.printString("Server address:",X,y,ANCHOR,
y+= CanvasHelper.printString(remoteAddress,X,y,ANCHOR,

y+= CanvasHelper.printString("Security settings:",X,y,ANCHOR,
y+= CanvasHelper.printString("Authenticated: " +
(authentication ? "Yes" : "No"),X,y,ANCHOR,
y+= CanvasHelper.printString("Encrypted: "+
(encryption ? "Yes" : "No"),X,y,ANCHOR,

}

}

}

121

Appendix C KlingsLib

BTServiceAttributeId.java
/*
* BTServiceAttributeId.java
*
* Version 1.0
*
* 9. June 2004
*
*
*
*
*
*
*/

package org.klings.wireless.BluetoothNumbers;

/**
* Defines constants for all Bluetooth service attribute IDs found in Section
* 4.5 "Attribute identifier codes Numeric IDS" in the Bluetooth
* Assigned Numbers document. The names are prefixed with the acronym for the
* profile they are related to. Hence, attributes related to the Service
* Discovery Protocol (SDP) are prefixed SDP_. Consult the Bluetooth Assigned
* Numbers document for more information.
* Last updated 09. june 2004.
*
* @author André N. Klingsheim

122 BTServiceAttributeId.java Appendix C

* @version 1.0
* @since 1.0
* @see <a href=
* "https://www.bluetooth.org/foundry/assignnumb/document/service_discovery">
* Bluetooth Assigned Numbers</a>
*/
public final class BTServiceAttributeId {

/**
* Defines the <code>ServiceRecordHandle</code> short UUID value.
* <code>SDP_SERVICERECORDHANDLE</code> is set to the constant value 0x0000.
*/
public static final int SDP_SERVICERECORDHANDLE = 0x0000;

/**
* Defines the <code>ServiceClassIDList</code> short UUID value.
* <code>SDP_SERVICECLASSIDLIST</code> is set to the constant value 0x0001.
*/
public static final int SDP_SERVICECLASSIDLIST = 0x0001;

/**
* Defines the <code>ServiceRecordState</code> short UUID value.
* <code>SDP_SERVICERECORDSTATE</code> is set to the constant value 0x0002.
*/
public static final int SDP_SERVICERECORDSTATE = 0x0002;

/**
* Defines the <code>ServiceID</code> short UUID value.
* <code>SDP_SERVICEID</code> is set to the constant value 0x0003.
*/
public static final int SDP_SERVICEID = 0x0003;

/**
* Defines the <code>ProtocolDescriptorList</code> short UUID value.
* <code>SDP_PROTOCOLDESCRIPTORLIST</code> is set to the constant value 0x0004.
*/
public static final int SDP_PROTOCOLDESCRIPTORLIST = 0x0004;

/**
* Defines the <code>BrowseGroupList</code> short UUID value.
* <code>SDP_BROWSEGROUPLIST</code> is set to the constant value 0x0005.
*/
public static final int SDP_BROWSEGROUPLIST = 0x0005;

/**
* Defines the <code>LanguageBaseAttributeIDList</code> short UUID value.
* <code>SDP_LANGUAGEBASEATTRIBUTEIDLIST</code> is set to the constant value
* 0x0006.
*/
public static final int SDP_LANGUAGEBASEATTRIBUTEIDLIST = 0x0006;

/**
* Defines the <code>ServiceInfoTimeToLive</code> short UUID value.
* <code>SDP_SERVICEINFOTIMETOLIVE</code> is set to the constant value 0x0007.
*/
public static final int SDP_SERVICEINFOTIMETOLIVE = 0x0007;

/**
* Defines the <code>ServiceAvailability</code> short UUID value.

Appendix C BTServiceAttributeId.java 123

* <code>SDP_SERVICEAVAILABILITY</code> is set to the constant value 0x0008.
*/
public static final int SDP_SERVICEAVAILABILITY = 0x0008;

/**
* Defines the <code>BluetoothProfileDescriptorList</code> short UUID value.
* <code>SDP_BLUETOOTHPROFILEDESCRIPTORLIST</code> is set to the constant value
* 0x0009.
*/
public static final int SDP_BLUETOOTHPROFILEDESCRIPTORLIST = 0x0009;

/**
* Defines the <code>DocumentationURL</code> short UUID value.
* <code>SDP_DOCUMENTATIONURL</code> is set to the constant value 0x000A.
*/
public static final int SDP_DOCUMENTATIONURL = 0x000A;

/**
* Defines the <code>ClientExecutableURL</code> short UUID value.
* <code>SDP_CLIENTEEXECUTABLEURL</code> is set to the constant value 0x000B.
*/
public static final int SDP_CLIENTEEXECUTABLEURL = 0x000B;

/**
* Defines the <code>IconURL</code> short UUID value.
* <code>SDP_ICONURL = 0x000C</code> is set to the constant value 0x000C.
*/
public static final int SDP_ICONURL = 0x000C;

/**
* Defines the <code>AdditionalProtocolDescriptorLists</code> short UUID
* value.
* <code>SDP_ADDITIONALPROTOCOLDESCRIPTORLISTS</code> is set to the constant
* value 0x000D.
*/
public static final int SDP_ADDITIONALPROTOCOLDESCRIPTORLISTS = 0x000D;

/**
* Defines the <code>GroupID</code> short UUID value.
* <code>SDP_GROUPID = 0x0200</code> is set to the constant value 0x0200.
*/
public static final int SDP_GROUPID = 0x0200;

/**
* Defines the <code>IpSubnet</code> short UUID value.
* <code>PAN_IPSUBNET</code> is set to the constant value 0x0200.
*/
public static final int PAN_IPSUBNET = 0x0200;

/**
* Defines the <code>VersionNumberList</code> short UUID value.
* <code>SDP_VERSIONNUMBERLIST</code> is set to the constant value 0x0200.
*/
public static final int SDP_VERSIONNUMBERLIST = 0x0200;

/**
* Defines the <code>ServiceDatabaseState</code> short UUID value.
* <code>SDP_SERVICEDATABASESTATE</code> is set to the constant value 0x0201.
*/

public static final int SDP_SERVICEDATABASESTATE = 0x0201;

/**
* Defines the <code>ServiceVersion</code> short UUID value.
* <code>SERVICEVERSION</code> is set to the constant value 0x0300.
*/
public static final int SERVICEVERSION = 0x0300;

/**
* Defines the <code>Externalnetwork</code> short UUID value.
* <code>CTP_EXTERNALNETWORK</code> is set to the constant value 0x0301.
*/
public static final int CTP_EXTERNALNETWORK = 0x0301;

/**
* Defines the <code>Network</code> short UUID value.
* <code>HFP_NETWORK</code> is set to the constant value 0x0301.
*/
public static final int HFP_NETWORK = 0x0301;

/**
* Defines the <code>SupportedDataStoresList</code> short UUID value.
* <code>SYNCP_SUPPORTEDDATASTORESLIST</code> is set to the constant value
* 0x0301.
*/
public static final int SYNCP_SUPPORTEDDATASTORESLIST = 0x0301;

/**
* Defines the <code>FaxClass1Support</code> attribute ID value.
* <code>FAXP_FAXCLASS1SUPPORT</code> is set to the constant value 0x0302.
*/
public static final int FAXP_FAXCLASS1SUPPORT = 0x0302;

/**
* Defines the <code>Remoteaudiovolumecontrol</code> attribute ID value.
* <code>GAP_REMOTEAUDIOVOLUMECONTROL</code> is set to the constant value
* 0x0302.
*/
public static final int GAP_REMOTEAUDIOVOLUMECONTROL = 0x0302;

/**
* Defines the <code>FaxClass2_0Support</code> attribute ID value.
* <code>FAXCLASS20SUPPORT</code> is set to the constant value 0x0303.
*/
public static final int FAXCLASS20SUPPORT = 0x0303;

/**
* Defines the <code>SupportedFormatsList</code> attribute ID value.
* <code>OPP_SUPPORTEDFORMATSLIST</code> is set to the constant value 0x0303.
*/
public static final int OPP_SUPPORTEDFORMATSLIST = 0x0303;

/**
* Defines the <code>FaxClass2Support</code> attribute ID value.
* <code>FAXCLASS2SUPPORT</code> is set to the constant value 0x0304.
*/
public static final int FAXCLASS2SUPPORT = 0x0304;

/**

Appendix C BTServiceAttributeId.java 125

* Defines the <code>AudioFeedbackSupport</code> attribute ID value.
* <code>AUDIOFEEDBACKSUPPORT</code> is set to the constant value 0x0305.
*/
public static final int AUDIOFEEDBACKSUPPORT = 0x0305;

/**
* Defines the <code>NetworkAddress</code> attribute ID value.
* <code>WAP_NETWORKADDRESS</code> is set to the constant value 0x0306.
*/
public static final int WAP_NETWORKADDRESS = 0x0306;

/**
* Defines the <code>WAPGateWay</code> attribute ID value.
* <code>WAP_WAPGATEWAY</code> is set to the constant value 0x0307.
*/
public static final int WAP_WAPGATEWAY = 0x0307;

/**
* Defines the <code>HomePageURL</code> attribute ID value.
* <code>WAP_HOMEPAGEURL</code> is set to the constant value 0x0308.
*/
public static final int WAP_HOMEPAGEURL = 0x0308;

/**
* Defines the <code>WAPStackType</code> attribute ID value.
* <code>WAP_WAPSTACKTYPE</code> is set to the constant value 0x0309.
*/
public static final int WAP_WAPSTACKTYPE = 0x0309;

/**
* Defines the <code>SecurityDescription</code> attribute ID value.
* <code>PAN_SECURITYDESCRIPTION</code> is set to the constant value 0x030A.
*/
public static final int PAN_SECURITYDESCRIPTION = 0x030A;

/**
* Defines the <code>NetAccessType</code> attribute ID value.
* <code>PAN_NETACCESSTYPE</code> is set to the constant value0x030B.
*/
public static final int PAN_NETACCESSTYPE = 0x030B;

/**
* Defines the <code>MaxNetAccessrate</code> attribute ID value.
* <code>PAN_MAXNETACCESSRATE</code> is set to the constant value 0x030C.
*/
public static final int PAN_MAXNETACCESSRATE = 0x030C;

/**
* Defines the <code>IPv4Subnet</code> attribute ID value.
* <code>PAN_IPV4SUBNET</code> is set to the constant value 0x030D.
*/
public static final int PAN_IPV4SUBNET = 0x030D;

/**
* Defines the <code>IPv6Subnet</code> attribute ID value.
* <code>PAN_IPV6SUBNET</code> is set to the constant value 0x030E.
*/
public static final int PAN_IPV6SUBNET = 0x030E;

/**
* Defines the <code>SupportedCapabalities</code> attribute ID value.
* <code>IMAGING_SUPPORTEDCAPABILITIES</code> is set to the constant value
* 0x0310.
*/
public static final int IMAGING_SUPPORTEDCAPABILITIES = 0x0310;

/**
* Defines the <code>SupportedFeatures</code> attribute ID value.
* <code>SupportedFeatures</code> is set to the constant value 0x0311.
*/
public static final int IMAGING_SUPPORTEDFEATURES = 0x0311;

/**
* Defines the <code>SupportedFeatures</code> attribute ID value.
* <code>HFP_SUPPORTEDFEATURES</code> is set to the constant value 0x0311.
*/
public static final int HFP_SUPPORTEDFEATURES = 0x0311;

/**
* Defines the <code>SupportedFunctions</code> attribute ID value.
* <code>IMAGING_SUPPORTEDFUNCTIONS</code> is set to the constant value 0x0312.
*/
public static final int IMAGING_SUPPORTEDFUNCTIONS = 0x0312;

/**
* Defines the <code>TotalImagingDataCapacity</code> attribute ID value.
* <code>IMAGING_TOTALIMAGINGDATACAPACITY</code> is set to the constant value
* 0x0313.
*/
public static final int IMAGING_TOTALIMAGINGDATACAPACITY = 0x0313;

/**
* Defines the <code>ServiceName</code> attribute ID value.
* <code>SDP_SERVICENAME</code> is set to the constant value 0x100.
*/
public static final int SDP_SERVICENAME = 0x100;

/**
* Defines the <code>ServiceDescription</code> attribute ID value.
* <code>SDP_SERVICEDESCRIPTION</code> is set to the constant value 0x101.
*/
public static final int SDP_SERVICEDESCRIPTION = 0x101;

/**
* Defines the <code>ProviderName</code> attribute ID value.
* <code>SDP_PROVIDERNAME</code> is set to the constant value 0x102.
*/
public static final int SDP_PROVIDERNAME = 0x102;

/**
* Useless default constructor.
* @deprecated
*/
public BTServiceAttributeId(){

}
}

Appendix C BTProtocol.java 127

BTProtocol.java
/*
* BTProtocol.java
*
* Version 1.0
*
* 09. June 2004
*
*
*
*
*
*
*/


/**
* Defines constants for all Bluetooth protocol numbers found in Section 4.3
* "Protocols" in the Bluetooth Assigned Numbers document.
* Maps short Bluetooth protocol UUIDs to corresponding protocol name.
*
* @version 1.0
* @since 1.0
* @see <a href=
*"https://www.bluetooth.org/foundry/assignnumb/document/service_discovery">
*/
public class BTProtocol{

/**
* Defines the <code>SDP</code> short UUID value.

128 BTProtocol.java Appendix C

* <code>SDP</code> is set to the constant value 0x0001.
*/
public static final int SDP = 0x0001;

/**
* Defines the <code>UDP</code> short UUID value.
* <code>UDP</code> is set to the constant value 0x0002
*/
public static final int UDP = 0x0002;

/**
* Defines the <code>RFCOMM</code> short UUID value.
* <code>RFCOMM</code> is set to the constant value 0x0003
*/
public static final int RFCOMM = 0x0003;
/**
* Defines the <code>TCP</code> short UUID value.
* <code>TCP</code> is set to the constant value 0x0004
*/
public static final int TCP = 0x0004;
/**
* Defines the <code>TCS_BIN</code> short UUID value.
* <code>TCS_BIN</code> is set to the constant value 0x0005
*/
public static final int TCS_BIN = 0x0005;

/**
* Defines the <code>TCS_AT</code> short UUID value.
* <code>TCS_AT</code> is set to the constant value 0x0006
*/
public static final int TCS_AT = 0x0006;

/**
* Defines the <code>OBEX</code> short UUID value.
* <code>OBEX</code> is set to the constant value 0x0008
*/
public static final int OBEX = 0x0008;

/**
* Defines the <code>IP</code> short UUID value.
* <code>IP</code> is set to the constant value 0x0009
*/
public static final int IP = 0x0009;

/**
* Defines the <code>FTP</code> short UUID value.
* <code>FTP</code> is set to the constant value 0x000A
*/
public static final int FTP = 0x000A;

/**
* Defines the <code>HTTP</code> short UUID value.
* <code>HTTP</code> is set to the constant value 0x000C
*/
public static final int HTTP = 0x000C;

/**
* Defines the <code>WSP</code> short UUID value.
* <code>WSP</code> is set to the constant value 0x000E

*/
public static final int WSP = 0x000E;

/**
* Defines the <code>BNEP</code> short UUID value.
* <code>BNEP</code> is set to the constant value 0x000F
*/
public static final int BNEP = 0x000F;

/**
* Defines the <code>UPNP</code> short UUID value.
* <code>UPNP</code> is set to the constant value 0x0010
*/
public static final int UPNP = 0x0010;

/**
* Defines the <code>HIDP</code> short UUID value.
* <code>HIDP</code> is set to the constant value 0x0011
*/
public static final int HIDP = 0x0011;

/**
* Defines the <code>HardcopyControlChannel</code> short UUID value.
* <code>HARDCOPYCONTROLCHAN</code> is set to the constant value 0x0012
*/
public static final int HARDCOPYCONTROLCHANNEL = 0x0012;

/**
* Defines the <code>HardcopyDataChannel</code> short UUID value.
* <code>HARDCOPYDATACHANNEL</code> is set to the constant value 0x0014
*/
public static final int HARDCOPYDATACHANNEL = 0x0014;

/**
* Defines the <code>HardcopyNotification</code> short UUID value.
* <code>HARDCOPYNOTIFICATION</code> is set to the constant value 0x0016
*/
public static final int HARDCOPYNOTIFICATION = 0x0016;

/**
* Defines the <code>AVCTP</code> short UUID value.
* <code>AVCTP</code> is set to the constant value 0x0017
*/
public static final int AVCTP = 0x0017;

/**
* Defines the <code>AVDTP</code> short UUID value.
* <code>AVDTP</code> is set to the constant value 0x0019
*/
public static final int AVDTP = 0x0019;

/**
* Defines the <code>CMTP</code> short UUID value.
* <code>CMTP</code> is set to the constant value 0x001B
*/
public static final int CMTP = 0x001B;

/**
* Defines the <code>UDI_C_Plane</code> short UUID value.

130 BTProtocol.java Appendix C

* <code>UDI_C_Plane</code> is set to the constant value 0x001D
*/
public static final int UDI_C_Plane = 0x001D;

/**
* Defines the <code>L2CAP</code> short UUID value.
* <code>L2CAP</code> is set to the constant value 0x0100
*/
public static final int L2CAP = 0x0100;

private static int[] BTProtos = {
SDP,
UDP,
TCP,
TCS_BIN,
TCS_AT,
IP,
FTP,
HTTP,
WSP,
BNEP,
UPNP,
HIDP,
HARDCOPYCONTROLCHANNEL,
HARDCOPYDATACHANNEL,
HARDCOPYNOTIFICATION,
AVCTP,
AVDTP,
CMTP,
UDI_C_Plane,
OBEX,
RFCOMM,
L2CAP};

private static String[] BTProtoStrings = {
"SDP",
"UDP",
"TCP",
"TCS_BIN",
"TCS_AT",
"IP",
"FTP",
"HTTP",
"WSP",
"BNEP",
"UPNP",
"HIDP",
"HardcopyControlChannel",
"HardcopyDataChannel",
"HardcopyNotification",
"AVCTP",
"AVDTP",
"CMTP",
"UDI_C_Plane",
"OBEX",
"RFCOMM",
"L2CAP"};

/**

* @deprecated
*/
public BTProtocol(){

}

/**
* Returns the protocolname corresponding to the short UUID, according to the
Bluetooth Assigned Numbers document
*
* @param shortUUID The short UUID to look up.
* @return Protocol name as <code>String</code>. <code>null</code> if the
shortUUID is
* not specified in the Bluetooth Assigned Numbers document.
*/

public static String protocolName(int shortUUID) {

//let's search for our UUID.
for (int i = BTProtos.length -1 ; i >= 0; i--) {

if(shortUUID == BTProtos[i]) {

return BTProtoStrings[i];
}
}

return null;
}
}

132 BTServiceClass.java Appendix C

BTServiceClass.java
/*
* BTServiceClass.java
*
* Version 1.0
*
* 9. June 2004
*
*
*
*
*
*
*/


/**
* Defines constants for all Bluetooth service class identifiers found in Section
* 4.4 "Service Class Identifiers and Names" in the Bluetooth
* Assigned Numbers document.
* Maps short Bluetooth service class UUIDs to corresponding service class name.
*
* @version 1.0
* @since 1.0
* @see <a href=
* "https://www.bluetooth.org/foundry/assignnumb/document/service_discovery">
*/

public final class BTServiceClass {

Appendix C BTServiceClass.java 133

/**
* Defines the <code>ServiceDiscoveryServerServiceClassID</code> short UUID
* value.
* <code>SERVICEDISCOVERYSERVERSERVICECLASSID</code> is set to the constant
* value 0x1000.
*/
public static final int SERVICEDISCOVERYSERVERSERVICECLASSID = 0x1000;

/**
* Defines the <code>BrowseGroupDescriptorServiceClassID</code> short UUID
* value.
* <code>BROWSEGROUPDESCRIPTORSERVICECLASSID</code> is set to the constant value
* 0x1001.
*/
public static final int BROWSEGROUPDESCRIPTORSERVICECLASSID = 0x1001;

/**
* Defines the <code>PublicBrowseGroup</code> short UUID value.
* <code>PUBLICBROWSEGROUP</code> is set to the constant value 0x1002.
*/
public static final int PUBLICBROWSEGROUP = 0x1002;

/**
* Defines the <code>SerialPort</code> short UUID value.
* <code>SERIALPORT</code> is set to the constant value 0x1101.
*/
public static final int SERIALPORT = 0x1101;

/**
* Defines the <code>LANAccessUsingPPP</code> short UUID value.
* <code>LANACCESSUSINGPPP</code> is set to the constant value 0x1102.
*/
public static final int LANACCESSUSINGPPP = 0x1102;

/**
* Defines the <code>DialupNetworking</code> short UUID value.
* <code>DIALUPNETWORKING</code> is set to the constant value 0x1103.
*/
public static final int DIALUPNETWORKING = 0x1103;

/**
* Defines the <code>IrMCSync</code> short UUID value.
* <code>IRMCSYNC</code> is set to the constant value 0x1104.
*/
public static final int IRMCSYNC = 0x1104;

/**
* Defines the <code>OBEXObjectPush</code> short UUID value.
* <code>OBEXOBJECTPUSH</code> is set to the constant value 0x1105.
*/
public static final int OBEXOBJECTPUSH = 0x1105;

/**
* Defines the <code>OBEXFileTransfer</code> short UUID value.
* <code>OBEXFILETRANSFER</code> is set to the constant value 0x1106.
*/
public static final int OBEXFILETRANSFER = 0x1106;

/**

* Defines the <code>IrMCSyncCommand</code> short UUID value.
* <code>IRMCSYNCCOMMAND</code> is set to the constant value 0x1107.
*/
public static final int IRMCSYNCCOMMAND = 0x1107;

/**
* Defines the <code>Headset</code> short UUID value.
* <code>HEADSET</code> is set to the constant value 0x1108.
*/
public static final int HEADSET = 0x1108;

/**
* Defines the <code>CordlessTelephony</code> short UUID value.
* <code>CORDLESSTELEPHONY</code> is set to the constant value 0x1109.
*/
public static final int CORDLESSTELEPHONY = 0x1109;

/**
* Defines the <code>AudioSource</code> short UUID value.
* <code>AUDIOSOURCE</code> is set to the constant value 0x110A.
*/
public static final int AUDIOSOURCE = 0x110A;

/**
* Defines the <code>AudioSink</code> short UUID value.
* <code>AUDIOSINK</code> is set to the constant value 0x110B.
*/
public static final int AUDIOSINK = 0x110B;

/**
* Defines the <code>A_V_RemoteControlTarget</code> short UUID value.
* <code>A_V_REMOTECONTROLTARGET</code> is set to the constant value 0x110C.
*/
public static final int A_V_REMOTECONTROLTARGET = 0x110C;

/**
* Defines the <code>AdvancedAudioDistribution</code> short UUID value.
* <code>ADVANCEDAUDIODISTRIBUTION</code> is set to the constant value 0x110D.
*/
public static final int ADVANCEDAUDIODISTRIBUTION = 0x110D;

/**
* Defines the <code>A_V_RemoteControl</code> short UUID value.
* <code>A_V_REMOTECONTROL</code> is set to the constant value 0x110E.
*/
public static final int A_V_REMOTECONTROL = 0x110E;

/**
* Defines the <code>VideoConferencing</code> short UUID value.
* <code>VIDEOCONFERENCING</code> is set to the constant value 0x110F.
*/
public static final int VIDEOCONFERENCING = 0x110F;

/**
* Defines the <code>Intercom</code> short UUID value.
* <code>INTERCOM</code> is set to the constant value 0x1110.
*/
public static final int INTERCOM = 0x1110;

/**
* Defines the <code>Fax</code> short UUID value.
* <code>FAX </code> is set to the constant value 0x1111.
*/
public static final int FAX = 0x1111;

/**
* Defines the <code>HeadsetAudioGateway</code> short UUID value.
* <code>HEADSETAUDIOGATEWAY</code> is set to the constant value 0x1112.
*/
public static final int HEADSETAUDIOGATEWAY = 0x1112;

/**
* Defines the <code>WAP</code> short UUID value.
* <code>WAP</code> is set to the constant value 0x1113.
*/
public static final int WAP = 0x1113;

/**
* Defines the <code>WAP_CLIENT</code> short UUID value.
* <code>WAP_CLIENT</code> is set to the constant value 0x1114.
*/
public static final int WAP_CLIENT = 0x1114;

/**
* Defines the <code>PANU</code> short UUID value.
* <code>PANU</code> is set to the constant value 0x1115.
*/
public static final int PANU = 0x1115;

/**
* Defines the <code>NAP</code> short UUID value.
* <code>NAP</code> is set to the constant value 0x1116.
*/
public static final int NAP = 0x1116;

/**
* Defines the <code>GN</code> short UUID value.
* <code>GN</code> is set to the constant value 0x1117.
*/
public static final int GN = 0x1117;

/**
* Defines the <code>DirectPrinting</code> short UUID value.
* <code>DIRECTPRINTING</code> is set to the constant value 0x1118.
*/
public static final int DIRECTPRINTING = 0x1118;

/**
* Defines the <code>ReferencePrinting</code> short UUID value.
* <code>REFERENCEPRINTING</code> is set to the constant value 0x1119.
*/
public static final int REFERENCEPRINTING = 0x1119;

/**
* Defines the <code>Imaging</code> short UUID value.
* <code>IMAGING</code> is set to the constant value 0x111A.
*/
public static final int IMAGING = 0x111A;

/**
* Defines the <code>ImagingResponder</code> short UUID value.
* <code>IMAGINGRESPONDER</code> is set to the constant value 0x111B.
*/
public static final int IMAGINGRESPONDER = 0x111B;

/**
* Defines the <code>ImagingAutomaticArchive</code> short UUID value.
* <code>IMAGINGAUTOMATICARCHIVE</code> is set to the constant value 0x111C.
*/
public static final int IMAGINGAUTOMATICARCHIVE = 0x111C;

/**
* Defines the <code>ImagingReferencedObjects</code> short UUID value.
* <code>IMAGINGREFERENCEDOBJECTS</code> is set to the constant value 0x111D.
*/
public static final int IMAGINGREFERENCEDOBJECTS = 0x111D;

/**
* Defines the <code>Handsfree</code> short UUID value.
* <code>HANDSFREE</code> is set to the constant value 0x111E.
*/
public static final int HANDSFREE = 0x111E;

/**
* Defines the <code>HandsfreeAudioGateway</code> short UUID value.
* <code>HANDSFREEAUDIOGATEWAY</code> is set to the constant value 0x111F.
*/
public static final int HANDSFREEAUDIOGATEWAY = 0x111F;

/**
* Defines the <code>DirectPrintingReferenceObjectsService</code> short UUID
* value.
* <code>DIRECTPRINTINGREFERENCEOBJECTSSERVICE</code> is set to the constant
* value 0x1120.
*/
public static final int DIRECTPRINTINGREFERENCEOBJECTSSERVICE = 0x1120;

/**
* Defines the <code>ReflectedUI</code> short UUID value.
* <code>REFLECTEDUI</code> is set to the constant value 0x1121.
*/
public static final int REFLECTEDUI = 0x1121;

/**
* Defines the <code>BasicPrinting</code> short UUID value.
* <code>BASICPRINTING</code> is set to the constant value 0x1122.
*/
public static final int BASICPRINTING = 0x1122;

/**
* Defines the <code>PrintingStatus</code> short UUID value.
* <code>PRINTINGSTATUS</code> is set to the constant value 0x1123.
*/
public static final int PRINTINGSTATUS = 0x1123;

/**
* Defines the <code>HumanInterfaceDeviceService</code> short UUID value.

* <code>HUMANINTERFACEDEVICESERVICE</code> is set to the constant value 0x1124.
*/
public static final int HUMANINTERFACEDEVICESERVICE = 0x1124;

/**
* Defines the <code>HardcopyCableReplacement</code> short UUID value.
* <code>HARDCOPYCABLEREPLACEMENT</code> is set to the constant value 0x1125.
*/
public static final int HARDCOPYCABLEREPLACEMENT = 0x1125;

/**
* Defines the <code>HCR_Print</code> short UUID value.
* <code>HCR_PRINT</code> is set to the constant value 0x1126.
*/
public static final int HCR_PRINT = 0x1126;

/**
* Defines the <code>HCR_Scan</code> short UUID value.
* <code>HCR_SCAN</code> is set to the constant value 0x1127.
*/
public static final int HCR_SCAN = 0x1127;

/**
* Defines the <code>Common_ISDN_Access</code> short UUID value.
* <code>COMMON_ISDN_ACCESS</code> is set to the constant value 0x1128.
*/
public static final int COMMON_ISDN_ACCESS = 0x1128;

/**
* Defines the <code>VideoConferencingGW</code> short UUID value.
* <code>VIDEOCONFERENCINGGW</code> is set to the constant value 0x1129.
*/
public static final int VIDEOCONFERENCINGGW = 0x1129;

/**
* Defines the <code>UDI_MT</code> short UUID value.
* <code>UDI_MT</code> is set to the constant value 0x112A.
*/
public static final int UDI_MT = 0x112A;

/**
* Defines the <code>UDI_TA</code> short UUID value.
* <code>UDI_TA</code> is set to the constant value 0x112B.
*/
public static final int UDI_TA = 0x112B;

/**
* Defines the <code>Audio_Video</code> short UUID value.
* <code>AUDIO_VIDEO</code> is set to the constant value 0x112C.
*/
public static final int AUDIO_VIDEO = 0x112C;

/**
* Defines the <code>SIM_Access</code> short UUID value.
* <code>SIM_ACCESS</code> is set to the constant value 0x112D.
*/
public static final int SIM_ACCESS = 0x112D;

/**

* Defines the <code>PnPInformation</code> short UUID value.
* <code>PNPINFORMATION</code> is set to the constant value 0x1200.
*/
public static final int PNPINFORMATION = 0x1200;

/**
* Defines the <code>GenericNetworking</code> short UUID value.
* <code>GENERICNETWORKING</code> is set to the constant value 0x1201.
*/
public static final int GENERICNETWORKING = 0x1201;

/**
* Defines the <code>GenericFileTransfer</code> short UUID value.
* <code>GENERICFILETRANSFER</code> is set to the constant value 0x1202.
*/
public static final int GENERICFILETRANSFER = 0x1202;

/**
* Defines the <code>GenericAudio</code> short UUID value.
* <code>GENERICAUDIO</code> is set to the constant value 0x1203.
*/
public static final int GENERICAUDIO = 0x1203;

/**
* Defines the <code>GenericTelephony</code> short UUID value.
* <code>GENERICTELEPHONY</code> is set to the constant value 0x1204.
*/
public static final int GENERICTELEPHONY = 0x1204;

/**
* Defines the <code>UPNP_Service</code> short UUID value.
* <code>UPNP_SERVICE</code> is set to the constant value 0x1205.
*/
public static final int UPNP_SERVICE = 0x1205;

/**
* Defines the <code>UPNP_IP_Service</code> short UUID value.
* <code>UPNP_IP_SERVICE</code> is set to the constant value 0x1206.
*/
public static final int UPNP_IP_SERVICE = 0x1206;

/**
* Defines the <code>ESDP_UPNP_IP_PAN</code> short UUID value.
* <code>ESDP_UPNP_IP_PAN</code> is set to the constant value 0x1300.
*/
public static final int ESDP_UPNP_IP_PAN = 0x1300;

/**
* Defines the <code>ESDP_UPNP_IP_LAP</code> short UUID value.
* <code>ESDP_UPNP_IP_LAP</code> is set to the constant value 0x1301.
*/
public static final int ESDP_UPNP_IP_LAP = 0x1301;

/**
* Defines the <code>ESDP_UPNP_L2CAP</code> short UUID value.
* <code>ESDP_UPNP_L2CAP</code> is set to the constant value 0x1302.
*/
public static final int ESDP_UPNP_L2CAP = 0x1302;

/**
* Defines the <code>VideoSource</code> short UUID value.
* <code>VIDEOSOURCE</code> is set to the constant value 0x1303.
*/
public static final int VIDEOSOURCE = 0x1303;

/**
* Defines the <code>VideoSink</code> short UUID value.
* <code>VIDEOSINK</code> is set to the constant value 0x1304.
*/
public static final int VIDEOSINK = 0x1304;

private static int[] ServiceClassIds = {
SERVICEDISCOVERYSERVERSERVICECLASSID,
BROWSEGROUPDESCRIPTORSERVICECLASSID,
PUBLICBROWSEGROUP,
SERIALPORT,
LANACCESSUSINGPPP,
DIALUPNETWORKING,
IRMCSYNC,
OBEXOBJECTPUSH,
OBEXFILETRANSFER,
IRMCSYNCCOMMAND,
HEADSET,
CORDLESSTELEPHONY,
AUDIOSOURCE,
AUDIOSINK,
A_V_REMOTECONTROLTARGET,
ADVANCEDAUDIODISTRIBUTION,
A_V_REMOTECONTROL,
VIDEOCONFERENCING,
INTERCOM,
FAX,
HEADSETAUDIOGATEWAY,
WAP,
WAP_CLIENT,
PANU,
NAP,
GN,
DIRECTPRINTING,
REFERENCEPRINTING,
IMAGING,
IMAGINGRESPONDER,
IMAGINGAUTOMATICARCHIVE,
IMAGINGREFERENCEDOBJECTS,
HANDSFREE,
HANDSFREEAUDIOGATEWAY,
DIRECTPRINTINGREFERENCEOBJECTSSERVICE,
REFLECTEDUI,
BASICPRINTING,
PRINTINGSTATUS,
HUMANINTERFACEDEVICESERVICE,
HARDCOPYCABLEREPLACEMENT,
HCR_PRINT,
HCR_SCAN,
COMMON_ISDN_ACCESS,
VIDEOCONFERENCINGGW,
UDI_MT,
UDI_TA,


AUDIO_VIDEO,
SIM_ACCESS,
PNPINFORMATION,
GENERICNETWORKING,
GENERICFILETRANSFER,
GENERICAUDIO,
GENERICTELEPHONY,
UPNP_SERVICE,
UPNP_IP_SERVICE,
ESDP_UPNP_IP_PAN,
ESDP_UPNP_IP_LAP,
ESDP_UPNP_L2CAP,
VIDEOSOURCE,
VIDEOSINK
};

private static String[] ServiceClassIdStrings = {
"ServiceDiscoveryServerServiceClassID",
"BrowseGroupDescriptorServiceClassID",
"PublicBrowseGroup",
"SerialPort",
"LANAccessUsingPPP",
"DialupNetworking",
"IrMCSync",
"OBEXObjectPush",
"OBEXFileTransfer",
"IrMCSyncCommand",
"Headset",
"CordlessTelephony",
"AudioSource",
"AudioSink",
"A_V_RemoteControlTarget",
"AdvancedAudioDistribution",
"A_V_RemoteControl",
"VideoConferencing",
"Intercom",
"Fax",
"HeadsetAudioGateway",
"WAP",
"WAP_CLIENT",
"PANU",
"NAP",
"GN",
"DirectPrinting",
"ReferencePrinting",
"Imaging",
"ImagingResponder",
"ImagingAutomaticArchive",
"ImagingReferencedObjects",
"Handsfree",
"HandsfreeAudioGateway",
"DirectPrintingReferenceObjectsService",
"ReflectedUI",
"BasicPrinting",
"PrintingStatus",
"HumanInterfaceDeviceService",
"HardcopyCableReplacement",
"HCR_Print",
"HCR_Scan",

"Common_ISDN_Access",
"VideoConferencingGW",
"UDI_MT",
"UDI_TA",
"Audio_Video",
"SIM_Access",
"PnPInformation",
"GenericNetworking",
"GenericFileTransfer",
"GenericAudio",
"GenericTelephony",
"UPNP_Service",
"UPNP_IP_Service",
"ESDP_UPNP_IP_PAN",
"ESDP_UPNP_IP_LAP",
"ESDP_UPNP_L2CAP",
"VideoSource",
"VideoSink"
};

/**
* @deprecated
*/
public BTServiceClass(){

}

/**
* Returns the service class name corresponding to the short UUID, according to
* the Bluetooth Assigned Numbers document.
* @param shortUUID The short UUID to look up.
* @return Service class name as <code>String</code>. <code>null</code>
* if the shortUUID is not specified in the Bluetooth Assigned Numbers
* document.
*/
public static String serviceClassName(int shortUUID) {

//let's search for our UUID.
for (int i = ServiceClassIds.length -1 ; i >= 0; i--) {

if(shortUUID == ServiceClassIds[i]) {

return ServiceClassIdStrings[i];
}
}

return null;
}

}

142 BTUUIDTool.java Appendix C

BTUUIDTool.java
/*
* BTUUIDTool.java
*
* Version 1.0
*
* 21. June 2004
*
*
*
*
*
*
*/


/**
* Translates 128-bit UUIDs to short UUIDs, returns the hex value of a short UUID
* as String.
*
* @version 1.0
* @since 1.0
*/
public class BTUUIDTool {

private static final String BTBase = "00001000800000805F9B34FB";
private static String preHex = "0x0000000";

/**
* @deprecated

Appendix C BTUUIDTool.java 143

*/
public BTUUIDTool(){

}

/**
* Returns the short UUID value of a long UUID.
*
* @param uuid UUID to be converted to short UUID
* @return Short UUID. -1 if the UUID is not a valid short UUID, meaning
* it is not based on the Bluetooth base UUID,
* 00000000-0000-1000-8000-00805F9B34FB.
*/
public static int shortUUID(UUID uuid){

if (uuid == null) return -1;

String id = uuid.toString();
int offset =id.length()-24;

if (id.substring(offset).equals(BTBase)) {
id = id.substring(0,offset);

}else return -1;

int result = -1;
try {
result = Integer.parseInt(id,16);
}catch(NumberFormatException nfe){
return -1;
}

return result;

}

/**
* Returns a zero padded hex value representing the short UUID. If you
* supply e.g. 1, you will get: 0x0001.
*
* @param shortUUID The short UUID to be represented as a
* <code>String</code>
* @return The short UUID hex value as <code>String</code>.
*/
public static String toHexString(int shortUUID){

if (shortUUID < 0xFFFF){
String hex = Integer.toHexString(shortUUID);
hex = preHex.substring(0,6-hex.length()) + hex;
return hex;
}else{
String hex = Integer.toHexString(shortUUID);
hex = preHex.substring(0,10-hex.length()) + hex;
return hex;

}
}

}

144 BluetoothInfoCanvas.java Appendix C

BluetoothInfoCanvas.java
/*
* BluetoothInfoCanvas.java
*
* Version 1.0
*
* 21. June 2004
*
*
*
*
*
*
*/

package org.klings.wireless.j2me;

import javax.microedition.lcdui.Canvas;
import javax.microedition.lcdui.Font;
import javax.microedition.lcdui.Graphics;
import javax.microedition.lcdui.Ticker;

/**
* BluetoothInfoCanvas retrieves and prints Bluetooth system properties
* from the Java/Bluetooth enabled host device. The output is correctly
* formated according to the screen-size of the device. The user can scroll
* up and down to see all the relevant properties. Like any other
* <code>Canvas</code>, <code>Commands</code> etc. can be added to the
* BluetoothInfoCanvas.
* Note that no methods are available for the BluetoothInfoCanvas. Just create
* a new BluetoothInfoCanvas and show it to the user.
*

Appendix C BluetoothInfoCanvas.java 145

* @version 1.0
* @since 1.0
* @see javax.microedition.lcdui.Canvas
*/
public class BluetoothInfoCanvas extends Canvas {

private Font plain,bold;

/*Size of canvas */
private int canvasHeight, canvasWidth;

private int plainHeight,boldHeight;

private int y = 0;

/* Constants used when drawing string */
private final int X = 1;
private int anchor = Graphics.LEFT|Graphics.TOP;

/* Offset used to keep track of which lines to draw */
int baseOffset = 0;

/* Keycodes. The user can scroll up and down in the canvas */
int upKey = getKeyCode(UP);
int downKey = getKeyCode(DOWN);

/**
* Constructs a new BluetoothInfoCanvas object.
*
*/
public BluetoothInfoCanvas() {
super();

canvasHeight = getHeight();
canvasWidth = getWidth();

/* Get height of fonts */
plain=Font.getFont(Font.FACE_SYSTEM, Font.STYLE_PLAIN, Font.SIZE_MEDIUM);
bold = Font.getFont(Font.FACE_SYSTEM, Font.STYLE_BOLD, Font.SIZE_MEDIUM);

/* heights to compute where to draw. */

setTitle("JABWT Information");
setTicker(new Ticker("JABWT Info Canvas, by Klings @ "+
"http://www.klings.org/nowires --- "));
}




g.fillRect(0,0, canvasWidth,canvasHeight);

g.setFont(plain);

y=2;
int i =0;

/*
* Set the offset to baseOffset. If base Offset is 0, all lines
* will be drawn. If baseOffset is e.g. -1, the first two lines
* will be skipped.
*/

int offset = baseOffset;
String temp = LocalDevice.getProperty("bluetooth.api.version");
String temp2 = null;
String[] content;

if (temp == null){

y += CanvasHelper.printString("Bluetoth system not available.",X,y,
anchor,plain,canvasWidth,g);

y += CanvasHelper.printString(
"Some JABWT devices require that you turn on Bluetooth"+
"before starting Java Bluetooth applications. If Bluetooth"
+"is already turned on, your device may not support JABWT.",
X,y,anchor,plain,canvasWidth,g);
return;
}

if (offset++ >=0){

y += CanvasHelper.printString("JABWT version:",X,y,anchor,
bold,canvasWidth,g);

y += CanvasHelper.printString(temp,X,y,anchor,plain,canvasWidth,g);

}

/* If the canvasHeight is exceeded, there is no need to draw more
* information.
*/

if (y > canvasHeight) return;

if (offset++ >=0){
temp = LocalDevice.getProperty("bluetooth.l2cap.receiveMTU.max");

if (temp != null){

y += CanvasHelper.printString("L2CAP Max Receive MTU :",X,y,
anchor,bold,canvasWidth,g);
y += CanvasHelper.printString(temp + " bytes",X,y,anchor,
plain,canvasWidth,g);


}
}

if (offset++ >=0){
temp = LocalDevice.getProperty("bluetooth.master.switch");

if (temp != null){

y += CanvasHelper.printString("Master/slave switch allowed:",
X,y,anchor,bold,canvasWidth,g);
y += CanvasHelper.printString(temp,X,y,anchor,plain,
canvasWidth,g);

}
}


if (offset++ >=0){
temp = LocalDevice.getProperty(
"bluetooth.sd.attr.retrievable.max");

if (temp != null){

"Max service record attributes received:",X,y,anchor,
canvasWidth,g);

}
}


if (offset++ >=0){
temp = LocalDevice.getProperty("bluetooth.connected.devices.max");

if (temp != null){

y += CanvasHelper.printString("Max connected devices:",X,y,
anchor,bold,canvasWidth,g);
canvasWidth,g);

}
}

if (offset++ >=0){
temp = LocalDevice.getProperty("bluetooth.sd.trans.max");

if (temp != null){

"Concurrent service discoveries:",X,y,anchor,bold,
canvasWidth,g);


canvasWidth,g);

}
}


if (offset++ >=0){
temp = LocalDevice.getProperty("bluetooth.connected.inquiry.scan");

if (temp != null){

"Inquiry scan during connection:",X,y,anchor,
y += CanvasHelper.printString(temp,X,y,anchor,

}
}

if (offset++ >=0){
temp = LocalDevice.getProperty("bluetooth.connected.page.scan");

if (temp != null){

"Page scan during connection:",X,y,anchor,

}
}

if (offset++ >=0){
temp = LocalDevice.getProperty("bluetooth.connected.inquiry");

if (temp != null){

y += CanvasHelper.printString("Inquiry during connection:",

}
}


if (offset++ >=0){

temp = LocalDevice.getProperty("bluetooth.connected.page");

if (temp != null){

y += CanvasHelper.printString("Paging during connection:",

}
}
}

protected void keyPressed(int keyCode) {

if(keyCode == downKey && y > canvasHeight) {

/*
* Show one property less in the top of the canvas, which
* gives one property more in the bottom of the canvas.
*/
baseOffset--;
}else if (keyCode == upKey && baseOffset < 0){

/*
* Show one property more in the top of the canvas, which
* gives one property less in the bottom of the canvas.
*/
baseOffset++;
}

repaint();
}

}

150 BluetoothServiceRecordCanvas.java Appendix C

BluetoothServiceRecordCanvas.java
/*
* BluetoothServiceRecordCanvas.java
*
* Version 1.0
*
* 21. June 2004
*
*
*
*
*
*
*/

import java.util.Enumeration;

import javax.bluetooth.DataElement;
import javax.microedition.lcdui.Canvas;
import javax.microedition.lcdui.Ticker;

import org.klings.wireless.BluetoothNumbers.BTProtocol;
import org.klings.wireless.BluetoothNumbers.BTServiceAttributeId;
import org.klings.wireless.BluetoothNumbers.BTServiceClass;
import org.klings.wireless.BluetoothNumbers.BTUUIDTool;

/**
* BluetoothServiceRecordCanvas prints the attributes of a Bluetooth
* <code>ServiceRecord</code>. Only attributes which are set in the

Appendix C BluetoothServiceRecordCanvas.java 151

* <code>ServiceRecord</code>
* will be printed. The user may scroll up and down in order to see the details
* for all attributes. The most common attributes related to the Bluetooth
* Service Discovery Profile (SDP) are shown. These are (with attribute
* IDs, in the order they are printed by BluetoothServiceRecordCanvas):
* <ul>
* <li>0x0100, ServiceName</li>
* <li>0x0101, ServiceDescription</li>
* <li>0x0102, ProviderName</li>
* <li>0x0000, ServiceRecordHandle</li>
* <li>0x0003, ServiceID</li>
* <li>0x0001, ServiceClassIDList</li>
* <li>0x0004, ProtocolDescriptorList</li>
* <li>0x0009, BluetoothProfileDescriptorList</li>
* <li>0x0007, ServiceInfoTimeToLive</li>
* <li>0x0008, ServiceAvailability</li>
* <li>0x000A, DocumentationURL</li>
* <li>0x000B, ClientExecutableURL</li>
* <li>0x000C, IconURL</li>
*
* </ul>
*
* @version 1.0
* @since 1.0
*/

public class BluetoothServiceRecordCanvas extends Canvas {

/* service record to display */
ServiceRecord sr = null;

int y = 0;

/* Different x values to indent lines */
final int X1 = 2;
final int X2 = 5;
final int X3 = 8;

/* Anchor for our text */
final int anchor = Graphics.LEFT|Graphics.TOP;

Font plain,bold;

int plainHeight,boldHeight;

/* Dimensions of canvas */
int canvasHeight, canvasWidth;

/* Offset used when there are more attributes than space in the canvas */
int attrOffset = 0;

/* Keycodes. The user can scroll up and down in the canvas */
int upKey = getKeyCode(UP);
int downKey = getKeyCode(DOWN);


/*
* The MIDlet can retrieve these URLs and open them in
* a wap browser.
*/
String clientExecutableURL = null;
String documentationURL = null;

/**
* Constructs a new BluetoothServiceRecordCanvas object.
*
* @param record The ServiceRecord to display.
*/

public BluetoothServiceRecordCanvas(ServiceRecord record) {
super();

this.sr = record;

/* Fonts for Bold and Plain text */
plain = Font.getFont(Font.FACE_SYSTEM, Font.STYLE_PLAIN, Font.SIZE_MEDIUM);
bold = Font.getFont(Font.FACE_SYSTEM, Font.STYLE_BOLD, Font.SIZE_MEDIUM);

/* font heights to compute where to draw. */

/* Canvas dimensions */
canvasHeight = getHeight();
canvasWidth = getWidth();

setTicker(new Ticker("Service Record Info Canvas, by Klings @ "+
"http://www.klings.org/nowires --- "));
}


g.fillRect(0,0, getWidth(),getHeight());

g.setFont(plain);

/* Start drawing two pixels from top of screen */
y = 2;


//temp String
String out = null;

int shortUUID = 0;

int offset = attrOffset;

/* Get the serviceName */


elm = (DataElement) sr.getAttributeValue(
BTServiceAttributeId.SDP_SERVICENAME);
if(elm != null && elm.getDataType() == DataElement.STRING
&& offset++ >=0) {

out = (String)elm.getValue();

/* Print servicename */
y += CanvasHelper.printString("Service name:",X1,y,anchor,
bold,canvasWidth-X1,g);
y += CanvasHelper.printString(out,X2,y,anchor,plain,
canvasWidth-X2,g);
}


/* Get the serviceDescription */
BTServiceAttributeId.SDP_SERVICEDESCRIPTION);

if (elm != null && elm.getDataType() == DataElement.STRING
&& offset++ >= 0) {

out = (String) elm.getValue();

/* Print serviceDescription */
y += CanvasHelper.printString("Service description:",X1,y,
anchor,bold,canvasWidth-X1,g);
canvasWidth-X2,g);
}


/* Get the providerName */
BTServiceAttributeId.SDP_PROVIDERNAME);

if (elm != null && elm.getDataType() == DataElement.STRING
&& offset++ >= 0) {


/* Print providerName */
y += CanvasHelper.printString("Provider name:",X1,y,anchor,
y += CanvasHelper.printString(out,X2,y,anchor,
plain,canvasWidth-X2,g);
}


/* Get the serviceRecordHandle */
BTServiceAttributeId.SDP_SERVICERECORDHANDLE);

if (elm != null && elm.getDataType() == DataElement.U_INT_4
&& offset++ >= 0) {


long var = elm.getLong();
out = "0x" + Long.toString(var,16);

/* Print serviceRecordHandle */
y += CanvasHelper.printString("ServiceRecordHandle:",X1,y,
}


/* Get the serviceId */
BTServiceAttributeId.SDP_SERVICEID);

if (elm != null && elm.getDataType() == DataElement.UUID
&& offset++ >= 0) {

UUID var = (UUID) elm.getValue();
out = "0x" + var.toString();

/* Print serviceId */
y += CanvasHelper.printString("ServiceId:",X1,y,anchor,

}


/* Get the serviceClassIdList */
BTServiceAttributeId.SDP_SERVICECLASSIDLIST);

if (elm != null && elm.getDataType() == DataElement.DATSEQ
&& offset++ >= 0) {

y += CanvasHelper.printString("ServiceClassIdList:",X1,y,

/* elm should be a DATSEQ of UUIDs */
DataElement elm2 = null;
UUID uuid = null;

try {
Enumeration e = (Enumeration) elm.getValue();

while(e.hasMoreElements()) {
elm2 = (DataElement) e.nextElement();

if (elm2.getDataType() == DataElement.UUID){
uuid = (UUID) elm2.getValue();
shortUUID = BTUUIDTool.shortUUID(uuid);
if(shortUUID != -1){
out = BTUUIDTool.toHexString(shortUUID) +", "+


BTServiceClass.serviceClassName(shortUUID);
}else{
out = "0x"+uuid.toString();
}


}
}

}catch(ClassCastException cce) {
y += CanvasHelper.printString("Unpredicted object",X2,y,anchor,

}

}


/* Get the protocolDescriptorList */
BTServiceAttributeId.SDP_PROTOCOLDESCRIPTORLIST);

&& offset++ >= 0) {

y += CanvasHelper.printString("ProtocolDescriptorList:",X1,y,

/*
* elm should be a DATSEQ of DATSEQ of UUID and
* optional parameters
*/
UUID uuid = null;

try {
/* Get enumeration to the "outer" DATSEQ */

/* Iterate through the "outer" DATSEQ */


if (elm2.getDataType() == DataElement.DATSEQ){

/* Get enumeration to the "inner" DATSEQ */
Enumeration e2 = (Enumeration) elm2.getValue();

elm3 = (DataElement) e2.nextElement();

/* The first element should be a UUID */


/* Get short UUID */
int id = BTUUIDTool.shortUUID(uuid);

if (id != -1){
out = BTUUIDTool.toHexString(id) + ", " +
BTProtocol.protocolName(id);
}else{
out = "0x"+uuid.toString();
}


/*
* If the protocol is L2CAP or RFCOMM, an
* optional parameter is set, the PSM for
* L2CAP or the channel number for RFCOMM.
*/
if ( (id == BTProtocol.L2CAP
|| id == BTProtocol.RFCOMM)
&& e2.hasMoreElements()) {

int type = elm3.getDataType();

/*
* The PSM or channel number is expected to
* be an int of some kind
*/
if (type >= DataElement.U_INT_1
&& type <= DataElement.INT_16){

if (id == BTProtocol.L2CAP) {
out = "PSM: " + elm3.getLong();

}else {

out = "Channel: "
+ elm3.getLong();

}

out,X3,y,
anchor,plain,canvasWidth-X3,g);

}

}//End check for protocols and elements in DatSeq
} //End check if elm3 is UUID
}//End check for Initial element == DatSeq
}

y += CanvasHelper.printString("Unpredicted object",X3,y,
anchor,plain,canvasWidth-X3,g);


}
}


/* Get the BluetoothProfileDescriptorList */
BTServiceAttributeId.SDP_BLUETOOTHPROFILEDESCRIPTORLIST);

&& offset++ >= 0) {

y += CanvasHelper.printString("ProfileDescriptorList:",X1,y,

/*
* elm should be a DATSEQ of DATSEQ pairs with a UUID and
* a version number
*/
UUID uuid = null;
long version = 0;

try {
/* Iterate through the "outer" DataElement sequence */


if (elm2.getDataType() == DataElement.DATSEQ){
/* Enumerate the "inner" DataElement sequence */
Enumeration e2 = (Enumeration) elm2.getValue();

/*
* This is a Dataelement pair.
* First DataElement is UUID.
*/



shortUUID = BTUUIDTool.shortUUID(uuid);

if (shortUUID != -1){
out = BTUUIDTool.toHexString(shortUUID) +
", " +
BTServiceClass.serviceClassName(shortUUID);
}else{
out = "0x" + uuid.toString();
}


}
/* The second DataElement is the version number,
* probably stored as an int.
*/

int type = elm3.getDataType();

if (type >= DataElement.U_INT_1
&& type <= DataElement.INT_16){

version = elm3.getLong();

out = "Version";
out += (version <= 0 ? " unknown":": "+ version);

} //End version check
}//End check of "inner" DataElement sequence
}//End iteration through "outer" DataElement sequence

y += CanvasHelper.printString("Unpredicted object",X3,y,anchor,

}

} //End BluetoothProfileDescriptorList


/* Get the serviceInfoTimeToLive */
BTServiceAttributeId.SDP_SERVICEINFOTIMETOLIVE);

&& offset++ >= 0) {

out = Long.toString(var)+ " seconds";

/* Print ServiceInfoTimeToLive */
y += CanvasHelper.printString("ServiceInfoTimeToLive:",X1,y,
canvasWidth-X2,g);
}


/* Get the serviceAvailability */
BTServiceAttributeId.SDP_SERVICEAVAILABILITY);

&& offset++ >= 0) {


out = Long.toString(var)+"/255";

/* Print ServiceAvailability */
y += CanvasHelper.printString("ServiceAvailability:",X1,y,
canvasWidth-X2,g);
}


/* Get the DocumentationURL */
BTServiceAttributeId.SDP_DOCUMENTATIONURL);

if (elm != null && elm.getDataType() == DataElement.URL
&& offset++ >= 0) {

documentationURL = (String) elm.getValue();

/* Print DocumentationURL */
y += CanvasHelper.printString("Documentation URL:",X1,y,anchor,
y += CanvasHelper.printString(documentationURL,X2,y,anchor,
}


/* Get the clientExecutableURL */
BTServiceAttributeId.SDP_CLIENTEEXECUTABLEURL);

&& offset++ >= 0) {

clientExecutableURL = (String) elm.getValue();

/* Print clientExecutableURL */
y += CanvasHelper.printString("Client Executable URL:",X1,y,
y += CanvasHelper.printString(clientExecutableURL,X2,y,anchor,
}


/* Get the iconURL */
BTServiceAttributeId.SDP_ICONURL);

&& offset++ >= 0) {


/* Print Icon URL */
y += CanvasHelper.printString("Icon URL:",X1,y,anchor,
}
}

/**
* Set a new <code>ServiceRecord</code> to display.
*
* @param record The <code>ServiceRecord</code> to display.
*/
public void setServiceRecord(ServiceRecord record) {
this.sr = record;
clientExecutableURL = null;
documentationURL = null;
attrOffset = 0;
repaint();
}

/**
* Returns the Documentation URL for the Bluetooth service described by the
* <code>ServiceRecord</code> currently displayed.
*
* @return The Documentation URL as a <code>String</code>.
* <code>null</code> if the DocumentationURL attribute is not set in the
*/
public String getDocumentationURL(){

return documentationURL;
}

/**
* Returns the Client Executable URL for the Bluetooth service described by the
*
* @return The Client Executable URL as a <code>String</code>.
* <code>null</code> if the ClientExecutableURL attribute is not set in
* the <code>ServiceRecord</code> currently displayed.
*/
public String getClientExecutableURL(){

return clientExecutableURL;
}

protected void keyPressed(int keyCode) {

if(keyCode == downKey && y > canvasHeight) {

/*
* Show one attribute less in the top of the canvas, which
* gives one attribute more in the bottom of the canvas.
*/

attrOffset--;
}else if (keyCode == upKey && attrOffset < 0){


/*
* Show one attribute more in the top of the canvas, which
* gives one attribute less in the bottom of the canvas.
*/

attrOffset++;
}

repaint();
}

}

162 CanvasHelper.java Appendix C

CanvasHelper.java
/*
* CanvasHelper.java
*
* Version 1.0
*
* 21. June 2004
*
*
*
*
*
*
*/




/**
* Formats <code>String</code>s so they can be printed in a
* <code>Canvas</code> without exceeding the <code>Canvas</code> width.
*
* @version 1.0
* @since 1.0
*/
public class CanvasHelper {

/**

Appendix C CanvasHelper.java 163

* @deprecated
*/
public CanvasHelper(){

}

/**
* Splits a <code>String</code>. Each fragment will not be longer
* than maxWidth when printed with the <code>Font</code> font.
*
* @param s The <code>String</code> to chop.
* @param font The <code>Font</code> used when calculating <code>String
* </code> lengths.
*
* @param maxWidth The maximum width of the resulting strings
* measured in pixels.
*
* @return <code>String</code> array containing one or more formatted
* strings. <code>null</code> if the supplied <code>String</code> or <code>
* Font</code> is <code>null</code>
*/
public static String[] splitString(String s, Font font, int maxWidth){

if(s == null || font == null) return null;

/* Return String immediately if it does not need formatting */
if(font.stringWidth(s)<maxWidth){

String[] res = {s};
return res;
}

maxWidth-= font.charWidth('i');

/*
* Compute avg. number of characters on a line by getting the
* average between the 'i' and 'M';
*/
int avgChars = maxWidth/
((font.charWidth('i')+font.charWidth('M'))/2);

int offset1 = 0;
int len = 0;
boolean longer = false;
boolean keepOn = false;
Vector v = new Vector();

while(s != null){

/* The remaining String is short enough, so we are done */
if(font.stringWidth(s)< maxWidth){
v.addElement(s);
s=null;
break;
}

164 CanvasHelper.java Appendix C

/*
* Check that the String length is bigger than avgChars
* to avoid nullpointer exception.
*/
len = s.length();
if(len > avgChars) len = avgChars;

/* If the String is to short, make it longer.
* Else make it shorter.
*/
if (font.substringWidth(s,0,len)< maxWidth) {

len++;

while(font.substringWidth(s,0,len++) < maxWidth){}

v.addElement(s.substring(0,len-1));
s = s.substring(len-1);
}
else {

len--;

while(font.substringWidth(s,0,len) > maxWidth)len--;

v.addElement(s.substring(0,len));
s = s.substring(len);
}

}

/*
* Copy the results from the Vector to a String array
* and return the results.
*/
String[] result = new String[v.size()];

for (int i = 0;i < result.length;i++){
result[i] = (String) v.elementAt(i);
}
return result;
}

/**
* Formats and prints a <code>String</code>, possibly over several lines.
*
* @param s The <code>String</code> to be printed.
* @param x The x coordinate of the anchor point.
* @param y The y coordinate of the anchor point.
* @param anchor The anchor point for positioning the text.
* @param f The <code>Font</code> to be used when drawing the text.
* @param maxWidth Maximum width of the strings, measured in pixels.
* @param g The <code>Graphics</code> object used when drawing text.
* @return The number of pixels used to draw the text in the y direction,
* given by: number of lines drawn * the <code>Font</code> height.
* @see javax.microedition.lcdui.Graphics#drawString(String str,int x,
* int y,int anchor)
*/

Appendix C CanvasHelper.java 165

public static int printString(String s, int x, int y, int anchor,
Font f, int maxWidth, Graphics g){

int yDelta = 0;
int fontHeight = f.getHeight();
g.setFont(f);

/*
* If the String does not need formatting, just print it.
* Else, chop it and print the Strings from the returned array.
*/
if (f.stringWidth(s) < maxWidth){
g.drawString(s,x,y,anchor);
yDelta = fontHeight;

}else{
String[] content = splitString(s,f,maxWidth);

for (int i = 0; i<content.length;i++){
g.drawString(content[i],x,y+yDelta,anchor);
yDelta += fontHeight;
}
}

/* Return the amount of pixels we have moved in the y direction */
return yDelta;

}
}

166

Bibliography
[1]: M. S. Gast, 802.11 Wireless Networks, First Edition, O'Reilly, 2002.

[2]: See http://www.mobilemag.com/content/100/104/C2783/

[3]: D. Gratton, Bluetooth Profiles, The Definitive Guide, First Edition, Prentice Hall, 2003.

[4]: See http://www.sun.com/smi/Press/sunflash/2004-02/

[5]: See http://www.nokia.com/nokia/0,,32913,00.html

[6]: B. Hopkings and R. Antony, Bluetooth for Java, First Edition, Apress, 2003.

[7]: Kumar et. al., Bluetooth Application Programming with the Java APIs, First Edition, Morgan
Kaufmann, 2004.

[8]: See http://forum.nokia.com

[9]: See http://sonyericsson.com/developer/

[10]: See http://groups.yahoo.com/group/JABWT/

[11]: See http://www.kjhole.com

[12]: J. Bray and C. Sturman, Bluetooth 1.1, Connect Without Cables, Second Edition, Prentice
Hall, 2002.

[13]: Bluetooth SIG, Specification of the Bluetooth System version 1.1, 2001.

[14]: See http://www.bluetooth.org

[15]: See http://www.bluetooth.com

[16]: See http://qualweb.bluetooth.org

[17]: C. Gehrmann, Bluetooth Security White Paper, 2002.

[18]: See http://www.symbian.com

[19]: See http://java.sun.com/products/cdc/

[20]: See http://java.sun.com/j2me/

[21]: See http://www.jcp.org

[22]: See http://www.jcp.org/en/jsr/detail?id=30

[23]: See http://java.sun.com/products/cldc/

[24]: Sun Microsystems, Inc., Connected, Limited Device Configuration. Specification Version
1.0a, 2000.

167

[25]: See http://java.sun.com/products/midp/




[29]: See http://www.nowires.org

[30]: See http://wireless.klings.org

[31]: See http://java.sun.com/products/j2mewtoolkit/

[32]: See http://www.rococosoft.com

[33]: See http://www.netbeans.org

[34]: See https://www.cvshome.org

[35]: See http://www.borland.com/mobile/jbuilder/

[36]: See http://www.eclipse.org

[37]: See http://eclipseme.sourceforge.net

[38]: J. Knudsen, Wireless Java: Developing with J2ME, Second Edition, Apress, 2003.

[39]: See http://developers.sun.com/techtopics/mobility/

[40]: See http://wap.klings.org

[41]: See http://www.me4se.org

[42]: See http://www.bluez.org

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