如果Spring MVC控制器方法没有返回值，返回什么？ [英] What to return if Spring MVC controller method doesn't return value?

问题描述

我正在使用jQuery的 $。getJSON（）来对我的简单Spring MVC后端进行异步调用。大多数Spring控制器方法如下所示：

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);
}   

我设置了一些东西，以便每个控制器返回 @ResponseBody 作为JSON，这是客户端所期望的。

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

但是当一个请求不应该返回任何请求时会发生什么内容到客户端？我可以：

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(...) {
    ...
}

如果不，这里使用的语法是什么？在此先感谢！

If not, what's the appropriate syntax to use here? Thanks in advance!

推荐答案

你可以返回void，然后你必须用@ResponseStatus标记方法（value = HttpStatus.OK ）你不需要@ResponseBody

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(...) {
    ...
}

只有获取方法返回200状态代码隐含，所有其他方法你做三件事之一：

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

• 返回void并使用标记方法@ResponseStatus（value = HttpStatus.OK）


• 返回一个对象标记为 @ResponseBody


• 返回 HttpEntity 实例

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

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