java - What to return if Spring MVC controller method doesn't return value?

Question

I am using jQuery's $.getJSON() to make asynchronous calls to my simple Spring MVC backend. Most of the Spring controller methods look like this:

@RequestMapping(value = "/someURL", method = RequestMethod.POST)
public @ResponseBody SomePOJO getSomeData(@ModelAttribute Widget widget,
    @RequestParam("type") String type) {
    return someDAO.getSomeData(widget, type);
}   

I have things set up so that each controller returns the @ResponseBody as JSON, which is what the client-side expects.

But what happens when a request isn't supposed to return any content to the client-side? Can I have:

@RequestMapping(value = "/updateSomeData" method = RequestMethod.POST)
public @ResponseBody void updateDataThatDoesntRequireClientToBeNotified(...) {
    ...
}

If not, what's the appropriate syntax to use here?

Answer 1

you can return void, then you have to mark the method with @ResponseStatus(value = HttpStatus.OK) you don't need @ResponseBody

@RequestMapping(value = "/updateSomeData" method = RequestMethod.POST)
@ResponseStatus(value = HttpStatus.OK)
public void updateDataThatDoesntRequireClientToBeNotified(...) {
    ...
}

Only get methods return a 200 status code implicity, all others you have do one of three things:

• Return void and mark the method with @ResponseStatus(value = HttpStatus.OK)
• Return An object and mark it with @ResponseBody
• Return an HttpEntity instance