In my application I use Jersey REST to serialize complex objects. This works quite fine. But there are a few method which simply return an int or boolean.
Jersey can
Are you writing a service or a client? In the service-end of things, you would simply write a MessageBodyWriter to serialize a stream of data to a Java object for your types. In my use cases, the services I'm writing output to JSON or XML, and in XML's case, I just throw one JAXB annotation on the top of my classes and I'm done.
Have you looked at the Jersey User guide regarding this?
3.6. Adding support for new representations