Java EE (Java Enterprise Edition) General Discussion

In the application, I get a problem of WebService. I use an eclipse plugin to parse the WSDL file which the customer sent to us and when I tested the methods of the WebService, there is only one method show me some exceptions like following(the others work very well):

INFO: Interceptor has thrown exception, unwinding now
org.apache.cxf.interceptor.Fault: Found element return but could not find matching RPC/Literal part

And the interface code is like following:
@WebMethod(operationName = "isTemporaryRecommendedUser", action = "")
@WebResult(name = "result", targetNamespace = "http://www.europages.com")
public boolean isTemporaryRecommendedUser(
@WebParam(name = "idUser", targetNamespace = "http://www.europages.com")
int idUser);

...what’s the problem?