如果你的控制器方法是用于文件处理，那么ResponseEntity是非常方便的:

@Controller
public class SomeController {
    @RequestMapping.....
    public ResponseEntity handleCall() {
        if (isFound()) {
            return new ResponseEntity(...);
        }
        else {
            return new ResponseEntity(404);
        }
    }
}

如果你想从控制器返回404状态，你只需要这样做

@RequestMapping(value = "/something", method = RequestMethod.POST)
@ResponseBody
public HttpStatus doSomething(@RequestBody String employeeId) {
    try {
        return HttpStatus.OK;
    } 
    catch (Exception ex) { 
         return HttpStatus.NOT_FOUND;
    }
}

通过这样做，当您想从控制器返回404时，您将收到一个404错误。

我想提一下，Spring默认提供了404异常(不仅是)。有关详细信息，请参阅Spring文档。所以如果你不需要自己的异常，你可以简单地这样做:

 @RequestMapping(value = "/**", method = RequestMethod.GET)
 public ModelAndView show() throws NoSuchRequestHandlingMethodException {
    if(something == null)
         throw new NoSuchRequestHandlingMethodException("show", YourClass.class);

    ...

  }

从Spring 5.0开始，你不需要创建额外的异常:

throw new ResponseStatusException(NOT_FOUND, "Unable to find resource");

此外，你可以用一个内置异常覆盖多个场景，你有更多的控制。

看到更多:

ResponseStatusException (javadoc) https://www.baeldung.com/spring-response-status-exception

简单地说，您可以使用web.xml添加错误代码和404错误页面。但是要确保404错误页面不能位于WEB-INF下面。

<error-page>
    <error-code>404</error-code>
    <location>/404.html</location>
</error-page>

这是最简单的方法，但也有局限性。假设您希望为该页添加与其他页相同的样式。这样你就不能那样做了。你必须使用@ResponseStatus(value = HttpStatus.NOT_FOUND)

使用setting配置web.xml

<error-page>
    <error-code>500</error-code>
    <location>/error/500</location>
</error-page>

<error-page>
    <error-code>404</error-code>
    <location>/error/404</location>
</error-page>

创建新控制器

   /**
     * Error Controller. handles the calls for 404, 500 and 401 HTTP Status codes.
     */
    @Controller
    @RequestMapping(value = ErrorController.ERROR_URL, produces = MediaType.APPLICATION_XHTML_XML_VALUE)
    public class ErrorController {


        /**
         * The constant ERROR_URL.
         */
        public static final String ERROR_URL = "/error";


        /**
         * The constant TILE_ERROR.
         */
        public static final String TILE_ERROR = "error.page";


        /**
         * Page Not Found.
         *
         * @return Home Page
         */
        @RequestMapping(value = "/404", produces = MediaType.APPLICATION_XHTML_XML_VALUE)
        public ModelAndView notFound() {

            ModelAndView model = new ModelAndView(TILE_ERROR);
            model.addObject("message", "The page you requested could not be found. This location may not be current.");

            return model;
        }

        /**
         * Error page.
         *
         * @return the model and view
         */
        @RequestMapping(value = "/500", produces = MediaType.APPLICATION_XHTML_XML_VALUE)
        public ModelAndView errorPage() {
            ModelAndView model = new ModelAndView(TILE_ERROR);
            model.addObject("message", "The page you requested could not be found. This location may not be current, due to the recent site redesign.");

            return model;
        }
}