On my current project, the server has to have the ability to receive image data embedded in a JSON object, therefore the JSON string representing the data is a base64 encoding of the binary image. The entity model (that is persisted to the DB through JPA/Hibernate) has the image data field of type byte.
Turns out that JBoss' RESTEasy is smart enough to use Jackson's ability to decode base64 text based on the type of the destination field.
That intuitive step by the framework is what helps give me a good feeling inside knowing I don't have to deal with type conversions, just what I want to do with the data.
Next task off the board please ....