We currently use XStream for encoding our web service inputs/outputs in XML. However we are considering switching to a binary format with code generator for multiple languages (protobuf, Thrift, Hessian, etc) to make supporting new clients easier and less reliant on hand-coding (also to better support our message formats which include binary data).

However most of our objects on the server are POJOs with XStream handling the serialization via reflection and annotations, and most of these libraries assume they will be generating the POJOs themselves. I can think of a few ways to interface an alternative library:

1. Write an XStream marshaler for the target format.

2. Write custom code to marshal the POJOs to/from the classes generated by the alternative library.

3. Subclass the generated classes to implement the POJO logic. May require some rewriting. (Also did I mention we want to use Terracotta?)

4. Use another library that supports both reflection (like XStream) and code generation.

However I'm not sure which serialization library would be best suited to the above techniques.