Servlet 3.1

Servlet 3.1
John Clingan, Principal Product Manager

The following is intended to outline our general product direction.
It is intended for information purposes only, and may not be
incorporated into any contract. It is not a commitment to deliver
any material, code, or functionality, and should not be relied upon
in making purchasing decisions. The development, release, and
timing of any features or functionality described for Oracle s
products remains at the sole discretion of Oracle.


Agenda

•  Servlet 3.0 recap
•  Servlet 3.1 Overview
•  NIO API
•  Protocol Upgrade
•  Security
•  Resources


Servlet 3.0 recap
•  Part of Java EE 6
•  Focused on
–  Ease-of-Development
–  Pluggability
–  Asynchronous support
–  Dynamic registration of servlets, filters and listeners
–  Security enhancements
•  Adoption
–  GlassFish 3.x, Tomcat 7, JBOSS, Caucho, IBM, Weblogic


Servlet 3.0 recap
Ease of Development
•  Annotations to declare
–  Servlets
–  Filters
–  Listeners
–  Security
•  Defaults for attributes of annotations


Example
@WebServlet( urlPatterns = {“/foo”} )
public class SimpleSample extends HttpServlet {

public void doGet(HttpServletRequest req,
HttpServletResponse res) {

}
}


Servlet 3.0 recap
Pluggability
•  Drag-and-drop model
•  Web frameworks as fully configured libraries
•  Contain “fragments” of web.xml
•  META-INF/web-fragment.xml
•  Extensions can register servlets, filters, listeners
dynamically
•  Extensions can also discover and process annotated
classes

Servlet 3.0 recap
Using pluggability
•  Bundle static resources and jsps in a jar that can be re-
used
•  Look for ready-to-use frameworks, libraries
•  Re-factor your libraries into re-usable, auto-configured
frameworks


Agenda

•  NIO API
•  Security
•  Resources


The content described in the following slides are subject to change
based on expert group discussions


JAVA EE 7 THEME: CLOUD / PAAS

Java EE 7 platform to be ready for the cloud


Java EE 7 PaaS support

•  Provide customers and users ability to leverage cloud
environments
•  Enable multi-tenancy
–  One application instance per tenant
–  Mapping to tenant done by container
–  Isolation between applications
•  Define metadata for services


Servlet 3.1
Feature set
•  Align with Java EE 7 for cloud support
–  For web container there will a virtual server mapping per tenant
–  Ability to load custom web resources per tenant
–  Use the services exposed in Java EE 7
•  Scale
–  Expose NIO2 API
•  Support newer technologies that leverage http protocol for the
initial handshake
–  Support general upgrade mechanism for protocols like WebSocket
•  Security enhancements


Agenda

•  NIO API
•  Security
•  Resources


Expose NIO API
Overview: NonBlocking IO
•  Add two listeners: ReadListener, WriteListener
•  Add two interfaces:
–  AsyncIOInputSource with abstract classes ServletInputStream,
ServletReader
–  AsyncIOOutputSink with abstract classes ServletOutputStream,
ServletWriter
•  Add APIs to ServletRequest, ServletResponse


Expose NIO API
javax.servlet.ReadListener
public interface ReadListener extends EventListener {

public void onDataAvailable(ServletRequest request);

public void onAllDataRead(ServletRequest request);

public void onError(Throwable t);
}


Expose NIO API
javax.servlet.WriteListener
public interface WriteListener extends EventListener {

public void onWritePossible(ServletResponse response);

public void onError(Throwable t);
}


Expose NIO API
javax.servlet.AsyncIOInputSource
public interface AsyncIOInputSource {

public int dataAvailable();

public boolean isFinished();

public isReady();
}


Expose NIO API
ServletInputStream, ServletReader

InputStream Reader

ServletInputStream AsyncIOInputSource ServletReader


Expose NIO API
javax.servlet.AsyncIOOutputSink
public interface AsyncIOOutputSink {

public boolean canWrite(int size);

public void complete();
}


Expose NIO API
NIOOutputStream, NIOWriter

OutputStream Writer

ServletOutputStream AsyncIOOutputSink ServletWriter


Expose NIO API
ServletRequest, ServletResponse
•  ServletRequest
–  Public ServletInputStream getServletInputStream()
–  Public ServletReader getServletReader()
–  public void addListener(ReadListener listener)
•  ServletResponse
–  Public ServletOutputStream getServletOutputStream()
–  Public ServletWriter getServletWriter()
–  public addListener(WriteListener listener)


Expose NIO API
Sample Usage
public class NIOSampleServlet extends HttpServlet
protected void doGet(HttpServletRequest request, HttpServletResponse response)
{
request.addListener(new ReadListener() {
public void onDataAvailable(ServletRequest request) {
ServletInputStream nis = request.getServletInputStream();
try {
nis.read(new byte[nis.dataAvailable()]);
…
}


Expose NIO API
Sample Usage (cont’d)

public void onAllDataRead(ServletRequest request) {
try {
request.getServletInputStream().close();
….
}

public void onError(Throwable t) { … }
});

final byte[] b = new byte[100];
….


Expose NIO API
Sample Usage (cont’d 2)
•  response.addListener(new WriteListener() {
public void onWritePossible(ServletResponse response) {
AsyncIOOutputStream nos = response.getAsyncIOOutputStream();
try {
nos.write(b);
nos.complete();
…
}

public void onError(Throwable t) { … }
});
}
}


Expose NIO API

•  Discussion with expert group on alternate approach
•  Use NIO 2 approach


Program Agenda

•  NIO API
•  Security
•  Resources


Upgrade

•  HTTP 1.1
•  Connection
•  Transition to some other, incompatible protocol
•  For example,
Upgrade: HTTP/2.0, SHTTP/1.3, IRC/6.9


Upgrade
Example: WebSocket
•  Protocol: IETF
•  API: W3C (JavaScript)
•  Bi-directional, full-duplex / TCP


Upgrade
WebSocket Example
•  GET /chat HTTP/1.1 •  HTTP/1.1 101 Switching Protocols
Host: server.example.com Upgrade: websocket
Upgrade: websocket Connection: Upgrade
Connection: Upgrade Sec-WebSocket-Accept:
Sec-WebSocket-Key: s3pPLMBiTxaQ9kYGzzhZRbK
dGhlIHNhbXBsZSBub25jZQ== +xOo=
Origin: http://example.com Sec-WebSocket-Protocol: chat
Sec-WebSocket-Protocol: chat,
superchat
Sec-WebSocket-Version: 13


Upgrade

HTTP Request

Servlet

….
upgrade(…); ProtocolHandler


Agenda

•  NIO API
•  Security
•  Resources


Security Enhancement

•  Made good progress in Servlet 3.0
•  Continue from where we left off
•  Include support for preventing against CSRF
•  Provide an easy way to support denying all unlisted http
methods
•  Encoding / escaping support to prevent XSS


Align with other Java EE JSRs

•  Integrate with Concurrency Utilities for Java EE
–  Utilize it Async programming model
•  Align with CDI
•  Align with Bean Validation
•  Align with Jcache (JSR 107)


Transparency
•  High level of transparency for all Java EE JSRs
•  Use java.net project to run our JSRs in the open
–  One java.net project per specification
•  Publicly viewable Expert Group mailing list archive
•  Users observer list gets copies of all emails to the EG
•  Download area
•  JIRA for issue tracking
•  Wiki and source repository at EG’s discretion
•  JCP.org private mailing list for administrative / confidential info


Agenda

•  NIO API
•  Security
•  Resources


Webtier related projects

•  https://servlet-spec.java.net
•  http://jcp.org/en/jsr/summary?id=340
•  webtier@glassfish.java.net
–  For users of GlassFish webtier


Tokyo 2012
April 4–6, 2012


Q&A


Servlet 3.1

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