The short answer is, you can. The longer answer is, you sorta can. Java and soap have conventions to declare what a variable is. Most of the simple types map. int to int, string to string and so on. Just beware one thing: complex/custom serialized types. If you keep the types simple it's rather easy. Check the documentation for your soap libraries and the standard, to see how they map the types.

Apache axis for instance, tells you which standards the follow and which ones they extend upon for convenience.