Hi Nagishetty,
You're not "forced" to use JSON.stringify to send to Jersey.. - I'm not too sure why you marked the question as answered, because that's not the answer you need.
JSON.stringify is a "noob" answer, someone that has no idea how JAX-RS or Jersey implementation works or how many different ways you can read the request payload in the Java side... you still can use that approach, but it's nothing else than an approach.
About your last question, you can just return your object instance with a build(), for instance:
public Response method() { return Response.status(__STATUS_CODE__).entity([your_instance]).build();
}
Hope it helps,
Dan.