Add body to exception 404 Not Found

Question

In the REST API generated with JHipster, I want to throw about 404 exceptions. This is usually done using

return new ResponseEntity<>(HttpStatus.NOT_FOUND);

which actually leads to a 404 response to the xhr request. The problem is that on the front, JHipster parses the response using

angular.fromJson(result)

and such a result is empty when 404 is the actual answer, which causes the analysis to fail.

If I point to an unmapped URI, say /api/user, while my controller maps to /api/users(pay attention to plural), I got 404 from the API, it has a body in it:

{
    "timestamp": "2016-04-25T18:33:19.947+0000",
    "status": 404,
    "error": "Not Found",
    "message": "No message available",
    "path": "/api/user/myuser/contact"
}

which correctly understands angular.

How can I create such a body? Is this an exception throwing spring or is someone throwing it?

: Trigger 404 Spring -MVC?, .

Answer 1

---

- 404 Not Found. - :

Map<String, String> errors = ....;
return ResponseEntity.status(HttpStatus.NOT_FOUND).body(errors);

, ResponseEntity, Exception, 404 Not Found. , NotFoundException like:

@ResponseStatus(code = HttpStatus.NOT_FOUND)
public class NotFoundException extends RuntimeException {}

, , - :

{  
   "timestamp":1461621047967,
   "status":404,
   "error":"Not Found",
   "exception":"NotFoundException",
   "message":"No message available",
   "path":"/greet"
}

, ExceptionHandler NotFoundException.

---

RESTful API , , , .

, , , APIException, , . /, :

public class APIException extends RuntimeException {
    private final int code;
    private final String message;

    APIException(int code, String message) {
        this.code = code;
        this.message = message;
    }

    public int code() {
        return code;
    }

    public String message() {
        return message;
    }
}

. , InvalidStateException:

@ResponseStatus(code = HttpStatus.BAD_REQUEST)
public class InvalidStateException extends APIException {
    public InvalidStateException() {
        super(1, "Application is in invalid state");
    }
}

, :

@ResponseStatus(code = HttpStatus.NOT_FOUND)
public class SomethingNotFoundException extends APIException {
    public SomethingNotFoundException() {
        super(2, "Couldn't find something!");
    }
}

ErrorController, JSON. :

@RestController
public class APIExceptionHandler extends AbstractErrorController {
    private static final String ERROR_PATH = "/error";
    private final ErrorAttributes errorAttributes;

    @Autowired
    public APIExceptionHandler(ErrorAttributes errorAttributes) {
        super(errorAttributes);
        this.errorAttributes = errorAttributes;
    }

    @RequestMapping(path = ERROR_PATH)
    public ResponseEntity<?> handleError(HttpServletRequest request) {
        HttpStatus status = getStatus(request);

        Map<String, Object> errors = getErrorAttributes(request, false);
        getApiException(request).ifPresent(apiError -> {
            errors.put("message" , apiError.message());
            errors.put("code", apiError.code());
        });
        // If you don't want to expose exception!
        errors.remove("exception");


        return ResponseEntity.status(status).body(errors);
    }

    @Override
    public String getErrorPath() {
        return ERROR_PATH;
    }

    private Optional<APIException> getApiException(HttpServletRequest request) {
        RequestAttributes attributes = new ServletRequestAttributes(request);
        Throwable throwable = errorAttributes.getError(attributes);
        if (throwable instanceof APIException) {
            APIException exception = (APIException) throwable;
            return Optional.of(exception);
        }

        return Optional.empty();
    }
}

, SomethingNotFoundException, JSON :

{  
   "timestamp":1461621047967,
   "status":404,
   "error":"Not Found",
   "message":"Couldn't find something!",
   "code": 2,
   "path":"/greet"
}

Answer 2

, ,

@ResponseBody
public ResponseEntity somthing() {
HttpHeaders headers = new HttpHeaders();
headers.add("Content-Type", "application/json; charset=utf-8");
return new ResponseEntity<>(new Gson().toJson("hello this is my message"), headers, HttpStatus.NOT_FOUND);
}