Developing SOAP Web Services using Java
- 1. DEVELOPING SOAP WEB SERVICES USING JAVA BY, KRISHNA VISWAMBHARAN 1
- 2. CONTENTS Developing SOAP Web Services using Java Developing Web Services Using Apache Axis Installing Axis for Web Services Running Axis without Tomcat/Servlet Engine Axis infrastructure and components Axis Web services programming Model 2
- 3. DEVELOPING SOAP WEB SERVICES USING JAVA The use of Java for developing SOAP applications enables scalable and portable applications to be built that also can interoperate with heterogeneous applications residing on different platforms by resolving the platform specific incompatibilities and other issues. To explore the features of java based SOAP implementations we chose to use Apache Axis 3
- 4. DEVELOPING WEB SERVICES USING APACHE AXIS Apache Axis is an open source implementation that provides a Java based SOAP implementation for developing web services. Apache Axis package contains the following :- A SOAP compliant runtime environment that can be used as a standalone server An API library and runtime environment for developing SOAP RPC and SOAP messaging-based applications and services Automatic serialization and deserialization for java objects Support for exposing EJBs as Web Services Tools for creating WSDL from Java classes Tools for deploying, monitoring and testing web services 4
- 5. INSTALLING AXIS FOR WEB SERVICES Steps involved in installing axis within an Apache Tomcat server:- 1. Download Apache Axis Toolkit 2. Download Apache Tomcat 4.0.3 and install it in the local system directory. 3. Navigate to the Axis installation home directory and copy the axis folder from AXIS_HOMEwebapps to TOMCAT_HOME webapps to deploy the Axis libraries as an Axis servlet 4. To deploy thee Axis libraries as a servlet in the TOMCAT container , create a context in the Tomcat server configuration by editing TOMCAT_HOME /conf/server.conf with <Context path=“/axis” docBase=“axis” debug=“0” reloadable=“true” crossContext=“true”> </Context> 5
- 6. 5. Add Axis specific supporting class libraries in the Tomcat environment 6. To test the Axis web services environment , start tomcat server 7. To compile and test applications , create a run script to ensure that the CLASSPATH in the development environment include the following 1. AXIS_HOME/lib/axis.jar 2. AXIS_HOME/lib/jaxrpc.jar 3. AXIS_HOME/lib/saaj.jar 4. AXIS_HOME/lib/commons-ogging.jar 5. AXIS_HOME/lib/xerces.jar 6. Etc.. 6
- 7. RUNNING AXIS WITHOUT TOMCAT/SERVLET ENGINE To start an Axis serve, run AXIS CLASSPATH script and execute the following:- java org.apache.axis.transport.http.SimpleAxisServer <port> o It is better to run the Axis environment from web server or a J2EE container 7
- 8. AXIS INFRASTRUCTURE AND COMPONENTS Axis Engine Acts as the SOAP runtime environment for processing the inbound and outbound messages To process messages, the Axis engine facilitates a series of handlers as chains to invoke and process the messages. The Axis engine process messages using a series of request handlers and after the invocation of the target service it returns as a series of response handlers. 8
- 9. Axis Administration Provides the administration and configuration information for the axis engine to enable runtime service chains and other SOAP services. Allows axis engine to be configured with a web service deployment descriptor (WSDD) WSDD file defines the supported transports ,global configuration of the axis engine as handlers , and the deployed services. 9
- 10. Tools for Emitting WSDL Axis facilitates WSDL support with the following three options:- http://jws.wiley.com/axis/services/AcmeCatalogSevice?WSDL Java org.apache.axis.wsdl.WSDL2Java <PROVIDER-WSDL-URL> Java2WSDL utility enables the generation of WSDL from java classes 10
- 11. Axis TCP Monitor That allows viewing,logging,and debugging of SOAP requests and responses. Allows testing of SOAP requests by editing and resubmitting them. Use of tcpmon utility requires a client listening port, a target SOAP server host and its port To view the tcpmon utility , Java org.apache.axis.utils.tcpmon <listeningport> <targetservername> <targetserverport> 11
- 12. AXIS WEB SERVICES PROGRAMMING MODEL Creating the service In an RPC based model, the Axis server engine transforms the java objects to XML and vice versa, using automatic serializer and deserializer mechanism during communication. In messaging-based communication model, in case of sending a response, the service returns a W3C Document object as a body of the SOAP response message. 12
- 13. Creating the service Requestor 1. RPC based communication model 1. Import Axis packages 2. Define the endpoint of the service 3. create service 4. create SOAP request call 5. set the target endpoint of the provider 6. set the service operation name and its methods 7. set the parameters required for the operation 8. set the return type parameters from the SOAP response. 9. invoke the services by sending the request and retrieve theresults. 13
- 14. 2. Messaging –based communication model 1.. Import Axis packages 2. Define the endpoint of the service 3. Read the XML document as input string 4. create a new service 5. create a SOAP request call using the service 6. set the target endpoint of the provider location 7. create a SOAP envelope with an XML payload 8. send the SOAP envelope with an XML payload to the dimension 9. in case of obtaining response message, the response message also will be a W3C document. 14
- 15. Creating the service requestor client from WSDL Axis provides a WSDL2Java utility for building java proxies and skeletons from WSDL obtained form the service provider. To create java proxy classes from WSDL, run the command, Java org.apache.axis.wsdl.WSDL2Java<PROVIDER-WSDL-URL> 15
- 16. Axis Deployment Model To deploy a service , ensure the CLASSPATH is set and run the command, java org.apache.axis.client.AdminClient deploy.wsdd To undeploy a service, java org.apache.axis.client.AdminClient undeploy.wsdd 16
- 17. Deploying Axis services using JWS files Allows the deployment of web services using java classes with .jws extensions. By placing java classes , with .jws extensions in the web applications directory during runtime ,Axis runtime automatically complies and deploys the classes with all of the methods and deployed services 17
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