What is the difference between ResponseEntity and @ResponseBody?

Question

I have a simple handler in my controller which returns a message

@RequestMapping(value = \"/message\")
@ResponseBody
public Message get() {
    return new Me         


        

Answer 1

HttpEntity represents an HTTP request or response consists of headers and body.

// Only talks about body & headers, but doesn't talk about status code
public HttpEntity(T body, MultiValueMap headers)

ResponseEntity extends HttpEntity but also adds a Http status code.

// i.e ResponseEntity = HttpEntity + StatusCode
public ResponseEntity(T body, MultiValueMap headers, HttpStatus statusCode)

Hence used to fully configure the HTTP response.

For Ex:

@ControllerAdvice 
public class JavaWebExeptionHandler {

    @Autowired
    ExceptionErrorCodeMap exceptionErrorCodeMap;

    @ExceptionHandler(RuntimeException.class)
    public final ResponseEntity handleAllExceptions(Exception ex) {
        Integer expCode = exceptionErrorCodeMap.getExpCode(ex.getClass());
        // We have not added headers to response here, If you want you can add by using respective constructor
        return new ResponseEntity(new ExceptionResponseBody(expCode, ex.getMessage()),
                HttpStatus.valueOf(expCode));
    }

}

@ResponseBody indicates that return value of method on which it is used is bound to the response body (Mean the return value of method is treated as Http response body)