Axis 的基础问题，高手来看看

我在给服务端传递参数的时候报了下面这个错误,有人知道是怎么回师吗?Unknown argument arg0 passed in method GETUser in web service GetUser
WDSL文档如下
  <?xml version="1.0" encoding="UTF-8" ?> 
- <wsdl:definitions targetNamespace="urn:DefaultNamespace" xmlns="http://schemas.xmlsoap.org/wsdl/" xmlns:apachesoap="http://xml.apache.org/xml-soap" xmlns:impl="urn:DefaultNamespace" xmlns:intf="urn:DefaultNamespace" xmlns:soapenc="http://schemas.xmlsoap.org/soap/encoding/" xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/" xmlns:wsdlsoap="http://schemas.xmlsoap.org/wsdl/soap/" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
- <wsdl:message name="GETUSERResponse">
  <wsdl:part name="GETUSERReturn" type="xsd:string" /> 
  </wsdl:message>
- <wsdl:message name="GETUSERRequest">
  <wsdl:part name="ID" type="xsd:string" /> 
  <wsdl:part name="IP" type="xsd:string" /> 
  </wsdl:message>
- <wsdl:portType name="GetSubject">
- <wsdl:operation name="GETUSER" parameterOrder="ID IP">
  <wsdl:input message="impl:GETUSERRequest" name="GETUSERRequest" /> 
  <wsdl:output message="impl:GETUSERResponse" name="GETUSERResponse" /> 
  </wsdl:operation>
  </wsdl:portType>
- <wsdl:binding name="GetSubjectportSoapBinding" type="impl:GetSubject">
  <wsdlsoap:binding style="rpc" transport="http://schemas.xmlsoap.org/soap/http" /> 
- <wsdl:operation name="GETUSER">
  <wsdlsoap:operation soapAction="" /> 
- <wsdl:input name="GETUSERRequest">
  <wsdlsoap:body encodingStyle="http://schemas.xmlsoap.org/soap/encoding/" namespace="urn:DefaultNamespace" use="encoded" /> 
  </wsdl:input>
- <wsdl:output name="GETUSERResponse">
  <wsdlsoap:body encodingStyle="http://schemas.xmlsoap.org/soap/encoding/" namespace="urn:DefaultNamespace" use="encoded" /> 
  </wsdl:output>
  </wsdl:operation>
  </wsdl:binding>
- <wsdl:service name="GetSubjectService">
+ <wsdl:port binding="impl:GetSubjectportSoapBinding" name="GetSubjectport">
  <wsdlsoap:address location="http://192.168.1.253:80/coa/webservices.nsf/getuser2?OpenWebService" /> 
  </wsdl:port>
  </wsdl:service>
  </wsdl:definitions>客户端源代码
import org.apache.axis.client.*;public class wsTestClient {
public static void main(String[] args) {
System.out.println("Start invoking");
try {
String strUrl="http://192.168.1.253:80/coa/webservices.nsf/getuser2?OpenWebService";
Service service=new Service();
Call call=(Call)service.createCall();
call.setTargetEndpointAddress(new java.net.URL(strUrl));
call.setOperationName("GETUser");
String username=""+call.invoke(new Object[]{"sdfs","dsd"});
System.out.println(username);
} catch (Exception e) {

System.err.println(e.toString());
}
System.out.println("Finished the invoking");
}
}