The brain damage required to expose IS Flow services as document literal or Soap Message style web services is in sharp contrast to the ease with which you can create Soap RPC web services using Integration Server.
I generally recommend using document literal web services to my clients because they offer more explicit control over error generation, ability to validate the schema(s) associated with the soap messages before processing its payload and the ability to log the raw soap messages received from the business partner or internal customer.
However, the work required to create and test the wrapper services that extract and validate the soap body elements, convert the body into the correct inputs for the “wrapped” service and then map the outputs of that service (or exceptions it throws) into a valid soap response is far beyond what is reasonable to expect developers to do these days.
I’ve toyed with the idea of creating a few utility services to make creating the wrapper service much, much easier, but knowing that WM is planning on replacing the IS soap stack with Glue over the next several releases, that might be a lot of wasted effort.
Generating a WSDL that will invoke your wrapper service is also harder than it should be. For some reason, you can’t just refer to the input and output documents of your wrapped service. You have to create a new document type that contains a “holder” document type. That document type contains only one child, a document reference to the document type you really want to use. When you inspect the generated WSDL the holder document is there, but when you generate a Flow or java client from the WSDL the method only uses the input document of the wrapped service.
BTW, my favorite way to generate Glue java clients from WSDL files is to use Eclipse with the Glue plugins. Just create a new Glue project and then add a web reference. The new web reference wizard prompts you for the location of the WSDL and generates the classes you need. Just add a new class with a main method to invoke your web service and you’re set. Easy!