java - What is the difference between ResponseEntity<T> and @ResponseBody?

Question

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

@RequestMapping(value = "/message")
@ResponseBody
public Message get() {
    return new Message(penguinCounter.incrementAndGet() + " penguin!");
}

At the same time I can use something like this

@RequestMapping(value = "/message")
ResponseEntity<Message> get() {
    Message message = new Message(penguinCounter.incrementAndGet() + " penguin!");
    return new ResponseEntity<Message>(message, HttpStatus.OK);
}

What is the difference betweet this two approaches? Let's not take into account HttpStatus :)

Answer 1

ResponseEntity will give you some added flexibility in defining arbitrary HTTP response headers. See the 4th constructor here:

http://docs.spring.io/spring/docs/3.0.x/api/org/springframework/http/ResponseEntity.html

ResponseEntity(T body, MultiValueMap<String,String> headers, HttpStatus statusCode) 

A List of possible HTTP response headers is available here:

http://en.wikipedia.org/wiki/List_of_HTTP_header_fields#Responses

Some commonly-used ones are Status, Content-Type and Cache-Control.

If you don't need that, using @ResponseBody will be a tiny bit more concise.