在Spring-MVC控制器中触发404？

Question

如何让Spring 3.0控制器触发404？

我有一个控制器,@RequestMapping(value = "/**", method = RequestMethod.GET)有些URL访问控制器,我希望容器能够提供404.

Answer 1

从Spring 3.0开始,你也可以抛出一个用@ResponseStatus注释声明的异常:

@ResponseStatus(value = HttpStatus.NOT_FOUND)
public class ResourceNotFoundException extends RuntimeException {
    ...
}

@Controller
public class SomeController {
    @RequestMapping.....
    public void handleCall() {
        if (isFound()) {
            // whatever
        }
        else {
            throw new ResourceNotFoundException(); 
        }
    }
}

Answer 2

重写您的方法签名,使其HttpServletResponse作为参数接受,以便您可以调用setStatus(int)它.

http://static.springsource.org/spring/docs/3.0.x/spring-framework-reference/html/mvc.html#mvc-ann-requestmapping-arguments

Answer 3

我想提一下,由Spring提供的默认值为404(不仅仅是).请参阅Spring文档了解详细信息 因此,如果您不需要自己的例外,您可以这样做:

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

    ...

  }

Answer 4

从Spring 3.0.2开始,您可以通过控制器的方法返回ResponseEntity <T>:

@RequestMapping.....
public ResponseEntity<Object> handleCall() {
    if (isFound()) {
        // do what you want
        return new ResponseEntity<>(HttpStatus.OK);
    }
    else {
        return new ResponseEntity<>(HttpStatus.NOT_FOUND);
    }
}

(ResponseEntity <T>比@ResponseBody注释更灵活 - 请参阅另一个问题)

Answer 5

您可以使用@ControllerAdvice来处理异常,@ ControllerAdvice注释类的默认行为将协助所有已知的控制器.

所以当你有任何控制器抛出404错误时会调用它.

如下:

@ControllerAdvice
class GlobalControllerExceptionHandler {
    @ResponseStatus(HttpStatus.NOT_FOUND)  // 404
    @ExceptionHandler(Exception.class)
    public void handleNoTFound() {
        // Nothing to do
    }
}

并在您的web.xml中映射此404响应错误,如下所示:

<error-page>
        <error-code>404</error-code>
        <location>/Error404.html</location>
</error-page>

希望有助于.

Answer 6

从Spring 5.0开始，您不必创建其他异常：

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

此外，您可以使用一个内置的例外情况涵盖多种情况，并且您拥有更多的控制权。

看更多：

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

Answer 7

如果您的控制器方法适用于文件处理,那么ResponseEntity非常方便:

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

Answer 8

我建议像这样抛出HttpClientErrorException

@RequestMapping(value = "/sample/")
public void sample() {
    if (somethingIsWrong()) {
        throw new HttpClientErrorException(HttpStatus.NOT_FOUND);
    }
}

您必须记住,只有在将任何内容写入servlet输出流之前,才能执行此操作.

Answer 9

虽然明确的答案是正确的,但有一种方法可以实现这一点,没有例外.该服务返回Optional<T>搜索到的对象,HttpStatus.OK如果找到则映射到404,如果为空则映射到404.

@Controller
public class SomeController {

    @RequestMapping.....
    public ResponseEntity<Object> handleCall() {
        return  service.find(param).map(result -> new ResponseEntity<>(result, HttpStatus.OK))
                .orElse(new ResponseEntity<>(HttpStatus.NOT_FOUND));
    }
}

@Service
public class Service{

    public Optional<Object> find(String param){
        if(!found()){
            return Optional.empty();
        }
        ...
        return Optional.of(data); 
    }

}