高手请指教！Axis2生成webservice客户端调用报错问题

最近刚下载了axis2相关包(axis2.war)及Eclipse插件，axis2-eclipse-service-archiver-wizard.zip及axis2-eclipse-codegen-wizard.zip。通过wsdl文件自动生成客户端如下：
自动生成代码核心方法如下：
/**
* Auto generated method signature
* @see com.eii.webservices.user.GetUserInfo#getUser
* @param param2

*/
public com.eii.webservices.user.GetUserInfoStub.GetUserout getUser(

com.eii.webservices.user.GetUserInfoStub.GetUserin0 param2)
throws java.rmi.RemoteException

{
try{
org.apache.axis2.client.OperationClient _operationClient = _serviceClient.createClient(_operations[0].getName());
_operationClient.getOptions().setAction("");
_operationClient.getOptions().setExceptionToBeThrownOnSOAPFault(true);



// create SOAP envelope with that payload
org.apache.axiom.soap.SOAPEnvelope env = null;

//Style is Doc.


env = toEnvelope(getFactory(_operationClient.getOptions().getSoapVersionURI()),
param2,
optimizeContent(new javax.xml.namespace.QName("",
"getUser")));

//adding SOAP headers
_serviceClient.addHeadersToEnvelope(env);
// create message context with that soap envelope
org.apache.axis2.context.MessageContext _messageContext = new org.apache.axis2.context.MessageContext() ;
_messageContext.setEnvelope(env);

// add the message contxt to the operation client
_operationClient.addMessageContext(_messageContext);
//execute the operation client
_operationClient.execute(true);
//执行到此处报空指针

org.apache.axis2.context.MessageContext _returnMessageContext = _operationClient.getMessageContext(
org.apache.axis2.wsdl.WSDLConstants.MESSAGE_LABEL_IN_VALUE);
org.apache.axiom.soap.SOAPEnvelope _returnEnv = _returnMessageContext.getEnvelope();


java.lang.Object object = fromOM(
_returnEnv.getBody().getFirstElement() ,
com.eii.webservices.user.GetUserInfoStub.GetUserout.class,
getEnvelopeNamespaces(_returnEnv));
_messageContext.getTransportOut().getSender().cleanup(_messageContext);
return (com.eii.webservices.user.GetUserInfoStub.GetUserout)object;

}catch(org.apache.axis2.AxisFault f){
org.apache.axiom.om.OMElement faultElt = f.getDetail();
if (faultElt!=null){
if (faultExeptionNameMap.containsKey(faultElt.getQName())){
//make the fault by reflection
try{
java.lang.String exceptionClassName = (java.lang.String)faultExeptionClassNameMap.get(faultElt.getQName());
java.lang.Class exceptionClass = java.lang.Class.forName(exceptionClassName);
java.lang.Exception ex=
(java.lang.Exception) exceptionClass.newInstance();
//message class
java.lang.String messageClassName = (java.lang.String)faultMessageMap.get(faultElt.getQName());
java.lang.Class messageClass = java.lang.Class.forName(messageClassName);
java.lang.Object messageObject = fromOM(faultElt,messageClass,null);
java.lang.reflect.Method m = exceptionClass.getMethod("setFaultMessage",
new java.lang.Class[]{messageClass});
m.invoke(ex,new java.lang.Object[]{messageObject});


throw new java.rmi.RemoteException(ex.getMessage(), ex);
}catch(java.lang.ClassCastException e){
// we cannot intantiate the class - throw the original Axis fault
throw f;
} catch (java.lang.ClassNotFoundException e) {
// we cannot intantiate the class - throw the original Axis fault
throw f;
}catch (java.lang.NoSuchMethodException e) {
// we cannot intantiate the class - throw the original Axis fault
throw f;
} catch (java.lang.reflect.InvocationTargetException e) {
// we cannot intantiate the class - throw the original Axis fault
throw f;
} catch (java.lang.IllegalAccessException e) {
// we cannot intantiate the class - throw the original Axis fault
throw f;
} catch (java.lang.InstantiationException e) {
// we cannot intantiate the class - throw the original Axis fault
throw f;
}
}else{
throw f;
}
}else{
throw f;
}
}
}

自己写的调用测试代码如下：

package com.eii.webservices.user;

import org.apache.axis2.AxisFault;

import com.eii.webservices.user.GetUserInfoStub.GetUserArgs;

public class Test {

public static void main(String[] args) {
com.eii.webservices.user.GetUserInfoStub stub;
try {
stub = new com.eii.webservices.user.GetUserInfoStub();

com.eii.webservices.user.GetUserInfoStub.GetUserin0 param6=


(com.eii.webservices.user.GetUserInfoStub.GetUserin0)getTestObject

(com.eii.webservices.user.GetUserInfoStub.GetUserin0.class);
// todo Fill in the param6 here
GetUserArgs arg = new GetUserArgs();
arg.setSysCode("EII");
arg.setUserId("A0071142");
param6.setGetUserin0(arg);
String s= stub.getUser( param6).getGetUserout();
System.out.println(s);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}//the default implementation should point to the right endpoint


}
public static org.apache.axis2.databinding.ADBBean getTestObject

(java.lang.Class type) throws Exception{
return (org.apache.axis2.databinding.ADBBean) type.newInstance();
}
}


结果在执行测试程序时，总是出错，错误信息如下：

java.lang.NullPointerException
at org.apache.axis2.description.ClientUtils.inferInTransport

(ClientUtils.java:85)
at org.apache.axis2.description.OutInAxisOperationClient.execute

(OutInAxisOperation.java:163)
at com.eii.webservices.user.GetUserInfoStub.getUser

(GetUserInfoStub.java:141)
at com.eii.webservices.user.Test.main(Test.java:21)
这个问题，不知道如何解决，也查不到为什么会出错，请高手指教！在线等