使用JAXB支持XSD版本控制

Question

I am currently working on an application that performs the task of importing or exporting some entities. The file format being used for the same is XML . JAXB is being used for XML binding.

The problem is present XSD that defines the structure of entities has no provision for versioning. How do I get started with defining versioned XSD and subsequently XML instance documents provided JAXB lies as the underlying binding framework ?

I have read that there are three possible ways of introducing versions in XSD .
1) Change the internal schema version attribute
2) Create a attribute like schemaVersion on the root element
3) Change the schema's target namespace.
Which one best suits the usecase mentioned below?

Use case: The changes made to the XSD in the next version may invalidate the existing elements. Although the schema itself may not be backward compatible but the application needs to provides support for handling all versions of schema.

Answer 1

XML is designed to facilitate change and flexibility in document structures. Unfortunately, JAXB isn't. The very act of compiling knowledge of document structure into your Java source code makes change to the document structure a lot more difficult.

If structural change is part of your agenda, I think you should seriously consider not using JAXB: technologies like XQuery and XSLT are much better suited to this scenario.