Make RPC/Encoded callouts from Apex

Question

We have an application which we need to integrate with salesforce.

Unfortunately this legacy application supports RPC SOAP calls only, we cannot use out of the box wsdl2apex to build the integration on it. Doing so gives the error:

Unsupported WSDL style 'rpc'. Only supports Document/literal/wrapped services.

We are considering an inbetween Heroku layer where we can build a custom java app to build the integration between salesforce and other application. Is there a better way to do this or how do you guys currently do an SOAP RPC call using apex? Is there any tool which can do SOAP RPC integration?

Answer 1

One option would be to craft the raw HttpRequest yourself and then parse the response.

A tool like SoapUI would be really useful here. You could use it to generate sample requests and responses. Then you manually write the Apex to make the same POST requests with your parameters and handle the response.

The XmlDom class will be useful for both reading and writing the required XML.