Spring Rest Json Web服务与异常处理程序

Question

I am getting an unconditional issue. I made my REST services in spring Json based. My service suppose to work with "Content-Type application/json" but whenever I made request without content-type then it throws an exception.

 org.springframework.web.HttpMediaTypeNotSupportedException: Content type 'text/plain;charset=UTF-8' not supported

However I am handling this exception with @ExceptionHandler , but spring is not able to handle this exception and my control is not coming in @ExceptionHandler method.

Please advice! how I can make sure that my incoming request needs to send content-type header ??

I wanted to catch this exception in my @ExceptionHandler method so that I can send error message with error code.

@RequestMapping(value = "/login", consumes = MediaType.APPLICATION_JSON, produces = MediaType.APPLICATION_JSON, method = RequestMethod.POST)
@ResponseBody
public ResponseEntity<ReponseWrapper> login(@Valid LoginRequest loginRequest,
        BindingResult results,) {
    //any code
}



 @ExceptionHandler(HttpMediaTypeNotSupportedException.class)
    @ResponseStatus(value = HttpStatus.UNSUPPORTED_MEDIA_TYPE)
    public @ResponseBody Map<String, Object> handleUnsupportedMediaTypeException(HttpMediaTypeNotSupportedException ex) throws IOException {
        Map<String, Object>  map = Maps.newHashMap();
        map.put("error", "Unsupported Media Type");
        map.put("cause", ex.getLocalizedMessage());
        map.put("supported", ex.getSupportedMediaTypes());
        return map;
    }

Answer 1

Well, the first issue is that @ExceptionHandler annotations on your controller methods handle only the exceptions thrown from within your controller; the exception that you experience gets thrown before the controller method is invoked and therefore does not get handled.

It would get handled if you had a case like this:

@Controller
public class TestController {

    @ResponseBody
    @RequestMapping(value = "/test", consumes = APPLICATION_JSON_VALUE, produces = 
        APPLICATION_JSON_VALUE)
    public ResponseEntity<ResponseWrapper> test(LoginRequest request)
        throws HttpMediaTypeNotSupportedException {
        throw new HttpMediaTypeNotSupportedException("");
    }

    @ExceptionHandler(HttpMediaTypeNotSupportedException.class)
    @ResponseStatus(value = HttpStatus.UNSUPPORTED_MEDIA_TYPE)
    public @ResponseBody Map<String, Object> handleUnsupportedMediaTypeException(
        HttpMediaTypeNotSupportedException ex) throws IOException {
        Map<String, Object> map = Maps.newHashMap();
        map.put("error", "Unsupported Media Type");
        map.put("cause", ex.getLocalizedMessage());
        map.put("supported", ex.getSupportedMediaTypes());
        return map;
    }
}

I suspect you would have to extend ExceptionHandlerExceptionResolver that would process only HttpMediaTypeNotSupportedException types. Or refer to this page and see if it helps.

Also, see whether you can use a newer version of Spring.

Answer 2

The @ExceptionHanlder annotation is not working because you have an invalid return type. The return type can be a String, which is interpreted as a view name or a ModelAndView object.