I came across a weird issue with proxy's generated by the Axis2 code generator from a WCF WSDL. Basically there is ambiguity between the String type defined in the Microsoft WSDL for primitive types which gets generated in the proxy and the java.lang.String. Supposedly this issue has been fixed but I still had an issue with the code generator plugin that installs with the Eclipse Ganymede plugin manager. Anyway's, to work around it I just navigated to the error:

And specified the FQ name for the Java string type and it worked fine: