ESB support for legacy RPC web services?

Question

I'm attempting to interface to some legacy web services that were written RPC style, rather than doc/wrapped or doc/literal. Unfortunately, it seems that Fusion doesn't like this old style of WSDL though, and I get a message that complains "The selected porttype is using a message that is invalid for the ESB because it is multi-part or has a simple type."
JDeveloper complains more specifically about the particular operation and message (operation Invoke and message InvokeRequest in the attached WSDL).
Searching of the forum archives turns up a few people who have had problems with this before, but no solutions. Anyone have any luck doing something like rewriting the WSDL by hand to map the RPC request to something the ESB can handle?
Also, I'm trying to set things up so the ESB acts as a proxy to this legacy service, and this means I will want the ESB to expose this as an RPC service for other legacy clients. I'm guessing that is out of the question?
Here's the WSDL:
<?xml version="1.0" encoding="UTF-8"?>
<definitions targetNamespace="http://datx.filogix.com/ZZZServicing" xmlns="http://schemas.xmlsoap.org/wsdl/" xmlns:impl="http://datx.filogix.com/ZZZServicing" xmlns:intf="http://datx.filogix.com/ZZZServicing" xmlns:apachesoap="http://xml.apache.org/xml-soap" xmlns:wsdlsoap="http://schemas.xmlsoap.org/wsdl/soap/" xmlns:soapenc="http://schemas.xmlsoap.org/soap/encoding/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:tns1="http://packaging.framework.datx.filogix.com" xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/">
<!--WSDL created by Apache Axis version: 1.4
Built on Apr 22, 2006 (06:55:48 PDT)-->
<wsdl:types>
<schema xmlns="http://www.w3.org/2001/XMLSchema" targetNamespace="http://packaging.framework.datx.filogix.com">
<import namespace="http://schemas.xmlsoap.org/soap/encoding/"/>
<complexType name="FXRequest">
<sequence>
<element name="auxData" nillable="true" type="xsd:string"/>
<element name="clientKey" nillable="true" type="xsd:string"/>
<element name="datxKey" nillable="true" type="xsd:string"/>
<element name="encoding" nillable="true" type="xsd:string"/>
<element name="password" nillable="true" type="xsd:string"/>
<element name="productType" nillable="true" type="xsd:string"/>
<element name="requestType" nillable="true" type="xsd:string"/>
<element name="schemaName" nillable="true" type="xsd:string"/>
<element name="serviceProvider" nillable="true" type="xsd:string"/>
<element name="timeout" nillable="true" type="xsd:int"/>
<element name="username" nillable="true" type="xsd:string"/>
</sequence>
</complexType>
<complexType name="Payload">
<sequence>
<element name="content" nillable="true" type="xsd:base64Binary"/>
<element name="encoding" nillable="true" type="xsd:string"/>
<element name="format" nillable="true" type="xsd:string"/>
<element name="schemaName" nillable="true" type="xsd:string"/>
</sequence>
</complexType>
<complexType name="ArrayOf_tns1_Payload">
<complexContent>
<restriction base="soapenc:Array">
<attribute ref="soapenc:arrayType" wsdl:arrayType="tns1:Payload[]"/>
</restriction>
</complexContent>
</complexType>
<complexType name="FXResponse">
<sequence>
<element name="clientKey" nillable="true" type="xsd:string"/>
<element name="datxKey" nillable="true" type="xsd:string"/>
<element name="externalKey" nillable="true" type="xsd:string"/>
<element name="payloads" nillable="true" type="tns1:ArrayOf_tns1_Payload"/>
<element name="resultCode" nillable="true" type="xsd:int"/>
<element name="resultDescription" nillable="true" type="xsd:string"/>
</sequence>
</complexType>
</schema>
</wsdl:types>
<message name="InvokeRequest">
<part name="fxReq" type="tns1:FXRequest"/>
<part name="xmlPayload" type="xsd:string"/>
</message>
<message name="InvokeResponse">
<part name="InvokeReturn" type="tns1:FXResponse"/>
</message>
<portType name="ZZZServicing">
<operation name="Invoke" parameterOrder="fxReq xmlPayload">
<input name="InvokeRequest" message="impl:InvokeRequest"/>
<output name="InvokeResponse" message="impl:InvokeResponse"/>
</operation>
</portType>
<binding name="ZZZServicingSoapBinding" type="impl:ZZZServicing">
<wsdlsoap:binding style="rpc" transport="http://schemas.xmlsoap.org/soap/http"/>
<operation name="Invoke">
<wsdlsoap:operation soapAction=""/>
<input name="InvokeRequest">
<wsdlsoap:body use="encoded" namespace="http://datx.filogix.com/ZZZServicing" encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"/>
</input>
<output name="InvokeResponse">
<wsdlsoap:body use="encoded" namespace="http://datx.filogix.com/ZZZServicing" encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"/>
</output>
</operation>
</binding>
<service name="ZZZServicingService">
<port name="ZZZServicing" binding="impl:ZZZServicingSoapBinding">
<wsdlsoap:address location="http://127.0.0.1:8890/datxservicing/services/ZZZServicing"/>
</port>
</service>
</definitions>

Answer 1

Making some progress on this....
So far, I've been able to generate an alternative WSDL for the legacy service. The service was built using Apache Axis for the SOAP handling, and it's possible to use the Axis Java2WSDL tool to generate a WSDL in doc/wrapped or doc/literal. The result is acceptable to JDeveloper.
Still unsure on how to deal with legacy clients that are going to be issuing RPC requests. I suspect the ESB is not going to like those coming in.....