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Articles taggués ‘java’

An operation with name ” already exists in this service

14/05/2009
8 commentaires

Here is a tip on how to avoid this type of exception with JAXWS but before let’s try to understand why your Service construciton fails…

This exception occurs when your service definition (the Java interface in our case) have some duplicates methods without the same number of parameters (ie method overloading). This exception is totally normal since it is quite logic that the resulting Web Service can only have unique operation names :

  • Check a WSDL file. Did you ever see the same operation X times?
  • The Web Service Engine generally tries to get the operation context from the operation name. Then it will unmarshall the parameters (it will not have a look to the operation parameters to choose the operation like it should be done in the Java Runtime).

Here is a service definition sample which will be used in this article :

package com.googlecode.chamerling.blog.jaxws.duplicate;
 
/**
 * @author Christophe HAMERLING
 *
 */
public interface Service {
 
	void foo();
 
	void foo(String bar);
}

So let’s implement this interface :

package com.googlecode.chamerling.blog.jaxws.duplicate;
 
import javax.jws.WebService;
 
/**
 * @author Christophe HAMERLING
 *
 */
@WebService
public class ServiceKo implements Service {
 
	public void foo() {
	}
 
	public void foo(String bar) {
	}
}

Let’s use the JaxWsServerFactoryBean CXF factory (other WS stacks should throw the same exception…) to expose this service :

import org.apache.cxf.jaxws.JaxWsServerFactoryBean;
 
/**
 * @author Christophe HAMERLING
 */
public class App {
 
	private static final String URL = "http://localhost:9999/chamerling/services/";
 
	public static void main(String[] args) {
		JaxWsServerFactoryBean svrFactory = new JaxWsServerFactoryBean();
		Service space = new ServiceKo();
		svrFactory.setAddress(URL + "ServiceKO");
		svrFactory.setServiceBean(space);
 
		org.apache.cxf.endpoint.Server service = svrFactory.create();
 
		System.out.println("Service is available at "
				+ service.getEndpoint().getEndpointInfo().getAddress());
 
	}
}

You should have a beautiful stack trace :

java.lang.IllegalArgumentException: An operation with name [{http://duplicate.jaxws.blog.chamerling.googlecode.com/}foo] already exists in this service
	at org.apache.cxf.service.model.InterfaceInfo.addOperation(InterfaceInfo.java:71)
	at org.apache.cxf.service.factory.ReflectionServiceFactoryBean.createOperation(ReflectionServiceFactoryBean.java:774)
	at org.apache.cxf.jaxws.support.JaxWsServiceFactoryBean.createOperation(JaxWsServiceFactoryBean.java:484)
	at org.apache.cxf.service.factory.ReflectionServiceFactoryBean.createInterface(ReflectionServiceFactoryBean.java:766)
	at org.apache.cxf.service.factory.ReflectionServiceFactoryBean.buildServiceFromClass(ReflectionServiceFactoryBean.java:361)
	at org.apache.cxf.jaxws.support.JaxWsServiceFactoryBean.buildServiceFromClass(JaxWsServiceFactoryBean.java:525)
	at org.apache.cxf.service.factory.ReflectionServiceFactoryBean.initializeServiceModel(ReflectionServiceFactoryBean.java:422)
	at org.apache.cxf.service.factory.ReflectionServiceFactoryBean.create(ReflectionServiceFactoryBean.java:190)
	at org.apache.cxf.jaxws.support.JaxWsServiceFactoryBean.create(JaxWsServiceFactoryBean.java:164)
	at org.apache.cxf.frontend.AbstractWSDLBasedEndpointFactory.createEndpoint(AbstractWSDLBasedEndpointFactory.java:100)
	at org.apache.cxf.frontend.ServerFactoryBean.create(ServerFactoryBean.java:117)
	at org.apache.cxf.jaxws.JaxWsServerFactoryBean.create(JaxWsServerFactoryBean.java:168)
	at com.googlecode.chamerling.blog.jaxws.duplicate.AppTest.testKoService(AppTest.java:37)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:585)
	at junit.framework.TestCase.runTest(TestCase.java:154)
	at junit.framework.TestCase.runBare(TestCase.java:127)
	at junit.framework.TestResult$1.protect(TestResult.java:106)
	at junit.framework.TestResult.runProtected(TestResult.java:124)
	at junit.framework.TestResult.run(TestResult.java:109)
	at junit.framework.TestCase.run(TestCase.java:118)
	at junit.framework.TestSuite.runTest(TestSuite.java:208)
	at junit.framework.TestSuite.run(TestSuite.java:203)
	at org.eclipse.jdt.internal.junit.runner.junit3.JUnit3TestReference.run(JUnit3TestReference.java:130)
	at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:460)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:673)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:386)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:196)

So the solution is to use the @WebParam @WebMethod annotation. Simply use this annotation to specify unique operation names in your service implementation :

package com.googlecode.chamerling.blog.jaxws.duplicate;
 
import javax.jws.WebMethod;
import javax.jws.WebService;
 
/**
 * @author Christophe HAMERLING
 *
 */
@WebService
public class ServiceOk implements Service {
 
	@WebMethod(operationName = "foo1")
	public void foo() {
	}
 
	@WebMethod(operationName = "foo2")
	public void foo(String bar) {
	}
}

Sources for this example are availble on my google code project (http://code.google.com/p/chamerling/) under http://code.google.com/p/chamerling/source/browse/#svn/trunk/blog/jaxws-duplicate

WebService , ,

Apache CXF Clients : null result when using bad client factory

09/04/2009
3 commentaires

Just a quick note to show that the client factory choice is important with Apache CXF 2.1.4.

The service interface definition :

package org.ow2.petals.usecase.soapaddressing.server;
 
import javax.jws.WebMethod;
import javax.jws.WebService;
 
/**
 * @author chamerling - eBM WebSourcing
 *
 */
@WebService
public interface AddressingService {
 
    /**
     * Get the local information
     * 
     * @return
     */
    @WebMethod
    String getInfo();
 
}

The client with the bad client factory :

package org.ow2.petals.usecase.soapaddressing.client;
 
import org.apache.cxf.frontend.ClientProxyFactoryBean;
import org.ow2.petals.usecase.soapaddressing.server.AddressingService;
 
/**
 * @author chamerling - eBM WebSourcing
 *
 */
public class BadFactory {
 
    /**
     * @param args
     */
    public static void main(String[] args) {
        ClientProxyFactoryBean factory = new ClientProxyFactoryBean();
        factory.setServiceClass(AddressingService.class);
        factory.setAddress("http://localhost:8084/petals/services/Service01");
        AddressingService client = (AddressingService) factory.create();
        String info = client.getInfo();
        System.out.println(info);
    }
}

With that client code, the Web Service is really invoked, but the result of the getInfo operation is null. So, let’s do it with the right client factory…

The client with the good client factory :

package org.ow2.petals.usecase.soapaddressing.client;
 
import org.apache.cxf.jaxws.JaxWsProxyFactoryBean;
import org.ow2.petals.usecase.soapaddressing.server.AddressingService;
 
/**
 * @author chamerling - eBM WebSourcing
 *
 */
public class GoodFactory {
 
    /**
     * @param args
     */
    public static void main(String[] args) {
        JaxWsProxyFactoryBean factory = new JaxWsProxyFactoryBean();
        factory.setServiceClass(AddressingService.class);
        factory.setAddress("http://localhost:8084/petals/services/Service01");
        AddressingService client = (AddressingService) factory.create();
        String info = client.getInfo();
        System.out.println(info);
    }
}

This time the result is not null and is really the one expected…

WebService , ,

Simple & Useful : Remote debugging with Ant

25/03/2009
Aucun commentaire

A Ant java call like :

<target name=”run”>
<java classname=”foo.bar.App” fork=”false”>
<classpath refid=”app.classpath” />
</java>
</target>

becomes :

<target name=”run”>
<java classname=”foo.bar.App” fork=”yes“>
<classpath refid=”app.classpath” />
<sysproperty key=”DEBUG” value=”true” />
<jvmarg value=”-Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000″ />
</java>
</target>

and is ready to be launch and ‘remote debugged’ from a tool like Eclipse IDE.

java

Handling static resources with Jetty

25/03/2009
Aucun commentaire

Here is a quick (and easy) tip on how to handle static resources with Jetty6 (this is really nice and quick to setup such things for a demo ;o)). Here is the code :

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package foo.bar;
 
import org.mortbay.jetty.Server;
import org.mortbay.jetty.handler.ContextHandlerCollection;
import org.mortbay.jetty.nio.SelectChannelConnector;
import org.mortbay.jetty.servlet.Context;
 
/**
 * @author Christophe HAMERLING - eBM WebSourcing
 *
 */
public class JettyServer {
 
    public static void main(String[] args) throws Exception {
        Server server = new Server();
        final ContextHandlerCollection contexts = new ContextHandlerCollection();
        final Context context = new Context(contexts, "/", Context.SESSIONS);
        context.setResourceBase(System.getProperty("user.home"));
        context.addServlet("org.mortbay.jetty.servlet.DefaultServlet", "/");
 
        final SelectChannelConnector nioConnector = new SelectChannelConnector();
        nioConnector.setPort(1978);
        server.addConnector(nioConnector);
        server.setHandler(contexts);
        server.start();
    }
}

This will display your home directory on http://localhost:1978

Cheers

java ,