Returning response entity from an Exception handler [Spring]

Question

I use the following code to handle all exceptions of type RuntimeException in class annotated with @ControllerAdvice

@ExceptionHandler(RuntimeException.class)
public ResponseEntity<JSONObject> RuntimeExceptionHandler(RuntimeException e) throws JSONException {
    JSONObject response = new JSONObject();
    response.put("message", e.getMessage());
    return new ResponseEntity<JSONObject>(response, HttpStatus.BAD_REQUEST);
}

It retuns the following response to the client in case of a ValidationException:

{
  "timestamp": 1496377230943,
  "status": 500,
  "error": "Internal Server Error",
  "exception": "javax.validation.ValidationException",
  "message": "Name does not meet expectations",
  "path": "/signup"
}

It is not what I expected. The status code is not BAD_REQUEST and the json is different from response.

It works fine if I change JSONObject to String and pass in a string message instead of a json object. I also put a break point before return statement and the response looks fine.

Note: There is another post here which:

1. Has no accepted answer.
2. Is annotating the method with @ResponseBody which I didn't.
3. Is not using JSONObject

Answer 1

A quick fix if you require a returned JSON format:

@ExceptionHandler(RuntimeException.class)
 public ResponseEntity<String> RuntimeExceptionHandler(RuntimeException e) {
  JSONObject response = new JSONObject();
  response.put("message", e.getMessage());
  return new ResponseEntity<String>(response.toString(), HttpStatus.BAD_REQUEST);
 }