web service

j'ai creer un web service qui retourne une liste mais j'ai eu cette exception :

WS00041: Service invocation threw an exception with message : null; Refer to the server log for more details
Exceptions details : java.lang.reflect.InvocationTargetException

javax.servlet.ServletException: java.lang.reflect.InvocationTargetException at org.glassfish.webservices.monitoring.WebServiceTesterServlet.doPost(WebServiceTesterServlet.java:342) at org.glassfish.webservices.monitoring.WebServiceTesterServlet.invoke(WebServiceTesterServlet.java:106) at org.glassfish.webservices.JAXWSServlet.doPost(JAXWSServlet.java:157) at javax.servlet.http.HttpServlet.service(HttpServlet.java:707) at javax.servlet.http.HttpServlet.service(HttpServlet.java:790) at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:318) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160) at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734) at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673) at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174) at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:416) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:283) at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459) at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167) at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:206) at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:180) at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235) at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119) at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:283) at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:200) at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:132) at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:111) at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77) at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:536) at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112) at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117) at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:56) at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137) at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:591) at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:571) at java.lang.Thread.run(Thread.java:748) Caused by: java.lang.reflect.InvocationTargetException at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.glassfish.webservices.monitoring.WebServiceTesterServlet.doPost(WebServiceTesterServlet.java:313) ... 32 more Caused by: com.sun.xml.ws.fault.ServerSOAPFaultException: Client received SOAP Fault from server: java.lang.NullPointerException Please see the server log to find more detail regarding exact cause of the failure. at com.sun.xml.ws.fault.SOAP11Fault.getProtocolException(SOAP11Fault.java:193) at com.sun.xml.ws.fault.SOAPFaultBuilder.createException(SOAPFaultBuilder.java:128) at com.sun.xml.ws.client.sei.StubHandler.readResponse(StubHandler.java:253) at com.sun.xml.ws.db.DatabindingImpl.deserializeResponse(DatabindingImpl.java:203) at com.sun.xml.ws.db.DatabindingImpl.deserializeResponse(DatabindingImpl.java:290) at com.sun.xml.ws.client.sei.SyncMethodHandler.invoke(SyncMethodHandler.java:119) at com.sun.xml.ws.client.sei.SyncMethodHandler.invoke(SyncMethodHandler.java:92) at com.sun.xml.ws.client.sei.SEIStub.invoke(SEIStub.java:161) at com.sun.proxy.$Proxy256.getTemp(Unknown Source) ... 37 more