270 likes | 281 Views
Development of Web Services. JAX-WS. Introduction. JAX-WS = Java API for XML Web Services JAX-WS - a universal technology to develop Web services Part of Java EE 5 and Java SE 6 JAX-WS 2.0 replaces JAX-RPC The centre of gravity moves from RPC-style to document-style web servi ces
E N D
Development of Web Services JAX-WS
Introduction • JAX-WS = Java API for XML Web Services • JAX-WS - a universal technology to develop Web services • Part of Java EE 5 and Java SE 6 • JAX-WS 2.0 replaces JAX-RPC • The centre of gravity moves from RPC-style to document-style web services • Reference Implementation – by GlassFish
History: JAX-RPC • JAX-RPC = Java API for XML-based RPC • First version (JAX-RPC 1.0) wasJSR-101, released in June 2002. • Its goal - to make simpler distributed development between Java and non-Java platforms • Allows to call any Web service from Java corresponding to its WSDL
JAX-RPC model JAX-RPC model has two sides: • Server-side programming model • Allows to develop Web service endpoints as Java objects or Enterprise JavaBeans, which run on the J2EE platform • Client-side programming model • Allows to access a remote Web service as if it were a local object, using methods that represent SOAP operations
Server-Side Programming • Two server-side programming models for creating Java EE Web service endpoints: • POJO endpoints • EJB3 Stateless Session Bean endpoints
JAX-WS Annotations • Annotations play a critical role in JAX-WS 2.0 • Annotations are used in mapping Java to WSDL and schema • Annotations are used in runtime to control how the JAX-WS runtime processes and responds to web service invocations • Annotations utilized by JAX-WS 2.0 are defined in separate JSRs: • JSR 181: Web Services Metadata for the JavaTM Platform • JSR 222: JavaTM Architecture for XML Binding (JAXB) 2.0 • JSR 224: JavaTM API for XML Web Services (JAX-WS) 2.0 • JSR 250: Common Annotations for the JavaTM Platform
Web Service Implementation • Write a POJO implementing the service • Add @WebService annotation to it • Optionally, inject a WebServiceContext • WebServiceContextmakes it possible for a web serviceendpoint implementation class to access messagecontext and security information relative to a request • Deploy the application • Point your clients at the WSDL • e.g. http://myserver/myapp/MyService?WSDL
Example: HelloWebService @WebService(name = "HelloWebService") @SOAPBinding( style = SOAPBinding.Style.DOCUMENT, use = SOAPBinding.Use.LITERAL, parameterStyle = SOAPBinding.ParameterStyle.WRAPPED) public class HelloWebService { @WebMethod public String hello(@WebParam(name = "name") String name){ return "Welcome " + name + " !!!"; } }
More Annotations • Web Services Metadata Annotations • @WebService • @WebMethod • @OneWay • @WebParam • @WebResult • JAX-WS Annotations • @RequestWrapper • @ResponseWrapper • @WebEndpoint • @WebFault • @WebServiceClient • @WebServiceRef
Web Service Deployment • To run Web service you’ll need to deploy it into web server with Java EE compliant web services • Java service endpoint usually is packaged as a web application in a WAR file • We will consider JBoss Application Server withJBoss Web Services (JBossWS)
JBoss Web Services • JBossWS is a JAX-WS compliant web service stack developed to be part of JBoss' Java EE 5 offering • At deployment time JBossWS will create services endpoints from annotated classes and publish the WSDL • At runtime SOAP requests are converted to JAVA invocations
Demo • The demo project: http://java-eim.googlecode.com/svn/trunk/ java-eim-demo-jbossws • Two simple Web services: • HelloWebService • CalculatorWebService • See instructions in README.txt
JBossWS Console http://localhost:8080/jbossws/
Client-Side Programming • JAX-WS client programming models: • Static Dynamic proxy client API • Dynamic Dispatch client API • Dynamic proxy client • Invokes a Web service based on a Service Endpoint Interface (SEI) which must be provided • Creating web service clients usually starts from the WSDL (“WSDL first” approach) • Special tools are used to generate client classes
Dispatch client API • Low level JAX-WS API to work at the XML message level or without any generated artifacts • Requires clients to construct messages or message payloads as XML • Requires an intimate knowledge of the desired message or payload structure
Client Side Generation (JBossWS) • JBossWS provide a tool for client side generation from WSDL wsconsume • From <JBOSS_HOME>/bin execute: wsconsume -k -p <package> <path_to_wsdl>
Generated Files • HelloWebServiceService.java • Service factory • HelloWebService.java • Service Endpoint Interface • Hello.java • Custom data type for request • HelloResponse.java • Custom data type for response • ObjectFactory.java • JAXB XML Registry • package-info.java • Holder for JAXB package annotations
Client Code import xxx.generated.hello.HelloWebService; import xxx.generated.hello.HelloWebServiceService; public class HelloWebServiceClient { public static void main(String[] args) { HelloWebServiceService helloFactory = new HelloWebServiceService(); HelloWebService helloService = helloFactory.getPort(HelloWebService.class); String response =helloService.hello("WebServiceClient"); } }
Web Service Invocation • A Java program invokes a method on a stub (local object representing the remote service) • The stub invokes routines in the JAX-WS runtime system • The runtime system converts the remote method invocation into a SOAP message • The runtime system transmits the message as an HTTP request
Server-Side Debugging (JBoss) • Add or un-comment the following line in run.bat rem JPDA options. Uncomment and modify as rem appropriateto enable remote debugging. set JAVA_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket, address=8787,server=y,suspend=n %JAVA_OPTS% 2. Create new “Remote Java Application” debug configuration in Eclipse: Run Open Debug Dialog
Server-Side Debugging (JBoss) • Start JBoss • Launch Debug configuration in Eclipse
Server-Side Debugging (JBoss) • Add breakpoint, e.g. to Web service code and run client • Server will stop at breakpoint
References • JAX-WS Annotations https://jax-ws.dev.java.net/jax-ws-ea3/docs/annotations.html • JBossWS Home http://labs.jboss.com/jbossws/ • JBossWS Wiki http://jbws.dyndns.org/mediawiki/index.php?title=JBossWS
References • JAX-WS Reference Implementation by GlassFish https://jax-ws.dev.java.net/ • JAX-WS Specification (JSR 224) http://jcp.org/en/jsr/detail?id=224 • Presentation about JAX-WS http://gceclub.sun.com.cn/java_one_online/2006/TS-1194/TS-1194.pdf