How to return custom objects in Apache Axis2 WebService

Question

I have been trying to deploy an Apache Axis2 WebService using Eclipse Juno, Maven and the java2wsdl plugin. However I keep running into a problem which I believe is due to mapping and hopefully someone can point me in the right direction.

I'm trying to call an operation on my WebService that takes in a parameter and returns a custom object but so far with no luck.

My Code

For talk sake I have the following class:

package com.example.models;
public class MyClass {
    // Does something
}

And I return a list of MyClass in the following operation:

package com.example.service;
import com.example.models;
public class MyService {
    public List<MyClass> getExampleData(// a parameter) {  
        // Do something
        return aListOfMyClass;
    }
}

My services.xml file:

<serviceGroup>
  <service name="MyWebService" targetNamespace="http://com.example.service.MyWebService/">
    <description>JNLPGenerator service</description>
    <schema schemaNamespace="http://com.example.service.MyWebService/" />
    <parameter name="ServiceClass" locked="false">com.example.service.MyWebService</parameter>
    <operation name="getExampleData">
      <messageReceiver class="org.apache.axis2.rpc.receivers.RPCMessageReceiver" />
    </operation>
  </service>
</serviceGroup>

The error:

When I deploy the WebService I get the following error message which is due to the class MyClass not being mapped.

<Exception>org.apache.axis2.AxisFault: org.apache.axis2.AxisFault: Mapping qname not fond for the package: com.example.models
    at org.apache.axis2.AxisFault.makeFault(AxisFault.java:430)
    at org.apache.axis2.rpc.receivers.RPCMessageReceiver.invokeBusinessLogic(RPCMessageReceiver.java:161)
    at org.apache.axis2.receivers.AbstractInOutMessageReceiver.invokeBusinessLogic(AbstractInOutMessageReceiver.java:40)
    at org.apache.axis2.receivers.AbstractMessageReceiver.receive(AbstractMessageReceiver.java:114)
    at org.apache.axis2.engine.AxisEngine.receive(AxisEngine.java:173)
    at org.apache.axis2.transport.http.util.RESTUtil.invokeAxisEngine(RESTUtil.java:135)
    at org.apache.axis2.transport.http.util.RESTUtil.processURLRequest(RESTUtil.java:130)
    at org.apache.axis2.transport.http.AxisServlet$RestRequestProcessor.processURLRequest(AxisServlet.java:817)
    at org.apache.axis2.transport.http.AxisServlet.doGet(AxisServlet.java:267)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:225)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1001)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:579)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
    at java.lang.Thread.run(Thread.java:722)
Caused by: java.lang.RuntimeException: org.apache.axis2.AxisFault: Mapping qname not fond for the package: com.example.models
    at org.apache.axis2.databinding.utils.BeanUtil.getPropertyQnameList(BeanUtil.java:261)
    at org.apache.axis2.databinding.utils.BeanUtil.getPullParser(BeanUtil.java:67)
    at org.apache.axis2.databinding.utils.reader.ADBXMLStreamReaderImpl.processProperties(ADBXMLStreamReaderImpl.java:994)
    at org.apache.axis2.databinding.utils.reader.ADBXMLStreamReaderImpl.next(ADBXMLStreamReaderImpl.java:831)
    at org.apache.axis2.util.StreamWrapper.next(StreamWrapper.java:71)
    at org.apache.axiom.om.impl.builder.StAXOMBuilder.parserNext(StAXOMBuilder.java:672)
    at org.apache.axiom.om.impl.builder.StAXOMBuilder.next(StAXOMBuilder.java:214)
    at org.apache.axiom.om.impl.llom.OMSerializableImpl.build(OMSerializableImpl.java:78)
    at org.apache.axiom.om.impl.llom.OMElementImpl.build(OMElementImpl.java:745)
    at org.apache.axiom.om.impl.llom.OMElementImpl.detach(OMElementImpl.java:723)
    at org.apache.axiom.om.impl.llom.OMNodeImpl.setParent(OMNodeImpl.java:105)
    at org.apache.axiom.om.impl.llom.OMElementImpl.addChild(OMElementImpl.java:297)
    at org.apache.axiom.om.impl.llom.OMElementImpl.addChild(OMElementImpl.java:213)
    at org.apache.axiom.soap.impl.llom.SOAPBodyImpl.addChild(SOAPBodyImpl.java:231)
    at org.apache.axis2.rpc.receivers.RPCUtil.processResponseAsDocLitWrapped(RPCUtil.java:422)
    at org.apache.axis2.rpc.receivers.RPCMessageReceiver.invokeBusinessLogic(RPCMessageReceiver.java:138)
    ... 25 more
Caused by: org.apache.axis2.AxisFault: Mapping qname not fond for the package: com.example.models
    at org.apache.axis2.databinding.utils.BeanUtil.getPropertyQnameList(BeanUtil.java:117)
    ... 40 more
</Exception>

So what I want to know is how to do this. I have read a similar post but to be honest I still don't really understand where I have to add this mapping to solve the problem. Also just to point the deploying of the web service is fine and the wsdl is also generated fine.

Sorry for a long post but hopefully someone can help me out..

Answer 1

The problem is due to Java2WSDL inability to work with Java Collections so the solution is not to use Java Collections when working Web Services and use Arrays instead.

Basically to get my web service working I made the following changes.

package com.example.service;
import com.example.models;
public class MyService {
    public MyClass[] getExampleData(// a parameter) {  
        // Do something
        return myClassArray;
    }
}

For anyone that wants more information about Java2WSDL inabilities with Java Collections, you can refer to Java web services: Axis2 Data Binding by IBM DeveloperWorks .