Lost in WSDL faults

[Wilfred Springer]

Hi all,

I've been staring at the following piece of WSDL for half a day now. This is a WSDL 
file that *is* accepted by Apache AXIS, but rejected by JWSDP. And I want to know why. 
I know for sure it has something to do with the faults found in 
HelloWorldExceptionMessage. JWSDP gives this error:

[wscompile] in message "HelloWorldExceptionMessage", part "helloWorldException"
must specify a "type" attribute

I *know* I can fix it by refering to a type instead of to an element, but I want to 
know *why* this is required. Both the WSDL specs and WS-I do not provide a lot of help 
here. Any help is appreciated.

<?xml version="1.0" encoding="UTF-8"?>
<!--

This WSDL file defines message part HelloWorldExceptionMessage,
containing a single part refering to the ns2:HelloWorldException
element. AXIS accepts this. JWSDP doesn't accept it.

-->
<definitions
  name="HelloWorldService"
  xmlns="http://schemas.xmlsoap.org/wsdl/";
  targetNamespace="http://agilejava.com/hw/20040226/";
  xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/";
  xmlns:soapenc="http://schemas.xmlsoap.org/soap/encoding/";
  xmlns:tns="http://agilejava.com/hw/20040226/";
  xmlns:ns2="http://agilejava.com/types/20040226/";
  xmlns:xsd="http://www.w3.org/2001/XMLSchema";>
  <types>
    <schema xmlns="http://www.w3.org/2001/XMLSchema";
      targetNamespace="http://agilejava.com/types/20040226/";>
      <element name="HelloWorldException" type="xsd:string"/>
    </schema>
  </types>
  <message name="HelloRequest">
    <part name="requestor" type="xsd:string"/>
  </message>
  <message name="HelloResponse">
    <part name="message" type="xsd:string"/>
  </message>
  <message name="HelloWorldExceptionMessage">
    <part name="helloWorldException" element="ns2:HelloWorldException"/>
  </message>
  <portType name="HelloWorldPortType">
    <operation name="helloWorld">
      <input message="tns:HelloRequest"/>
      <output message="tns:HelloResponse"/>
      <fault name="helloWorldException" message="tns:HelloWorldExceptionMessage"/>
    </operation>
  </portType>
  <binding name="HelloWorldBinding" type="tns:HelloWorldPortType">
    <soap:binding style="rpc" transport="http://schemas.xmlsoap.org/soap/http"/>
    <operation name="helloWorld">
      <soap:operation soapAction=""/>
      <input>
        <soap:body
          encodingStyle="http://schemas.xmlsoap.org/soap/encoding/";
          namespace="http://agilejava.com/hw/20040226/";
          use="encoded"/>
      </input>
      <output>
        <soap:body
          encodingStyle="http://schemas.xmlsoap.org/soap/encoding/";
          namespace="http://agilejava.com/hw/20040226/";
          use="encoded"/>
      </output>
      <fault name="helloWorldException">
        <soap:fault name="helloWorldException"
          encodingStyle="http://schemas.xmlsoap.org/soap/encoding/";
          namespace="http://agilejava.com/hw/20040226/";
          use="encoded"/>
      </fault>
    </operation>
  </binding> 
  <service name="HelloWorldService">
    <port name="HelloWorldPort"
      binding="tns:HelloWorldBinding">
      <soap:address location="http://agilejava.com/hw/20040226"/>
    </port>
  </service>
</definitions>