How return error message in spring mvc @Controller

Question

I am using methods like this

@RequestMapping(method = RequestMethod.GET)
public ResponseEntity getUser(@RequestHeader(value=\"Access-ke         


        

Answer 1

Evaluating the error response from another service invocated...

This was my solution for evaluating the error:

try {
        return authenticationFeign.signIn(userDto, dataRequest);
    }catch(FeignException ex){

        //ex.status();

        if(ex.status() == HttpStatus.UNAUTHORIZED.value()){
            System.out.println("is a error 401");
            return new ResponseEntity<>(HttpStatus.UNAUTHORIZED);
        }
        return new ResponseEntity<>(HttpStatus.OK);

    }

Answer 2

return new ResponseEntity<>(GenericResponseBean.newGenericError("Error during the calling the service", -1L), HttpStatus.EXPECTATION_FAILED);

Answer 3

Here is an alternative. Create a generic exception that takes a status code and a message. Then create an exception handler. Use the exception handler to retrieve the information out of the exception and return to the caller of the service.

http://javaninja.net/2016/06/throwing-exceptions-messages-spring-mvc-controller/

public class ResourceException extends RuntimeException {

    private HttpStatus httpStatus = HttpStatus.INTERNAL_SERVER_ERROR;

    public HttpStatus getHttpStatus() {
        return httpStatus;
    }

    /**
     * Constructs a new runtime exception with the specified detail message.
     * The cause is not initialized, and may subsequently be initialized by a
     * call to {@link #initCause}.
     * @param message the detail message. The detail message is saved for later retrieval by the {@link #getMessage()}
     *                method.
     */
    public ResourceException(HttpStatus httpStatus, String message) {
        super(message);
        this.httpStatus = httpStatus;
    }
}

Then use an exception handler to retrieve the information and return it to the service caller.

@ControllerAdvice
public class ExceptionHandlerAdvice { 

    @ExceptionHandler(ResourceException.class)
    public ResponseEntity handleException(ResourceException e) {
        // log exception 
        return ResponseEntity.status(e.getHttpStatus()).body(e.getMessage());
    }         
} 

Then create an exception when you need to.

throw new ResourceException(HttpStatus.NOT_FOUND, "We were unable to find the specified resource.");

Answer 4

As Sotirios Delimanolis already pointed out in the comments, there are two options:

Return ResponseEntity with error message

Change your method like this:

@RequestMapping(method = RequestMethod.GET)
public ResponseEntity getUser(@RequestHeader(value="Access-key") String accessKey,
                              @RequestHeader(value="Secret-key") String secretKey) {
    try {
        // see note 1
        return ResponseEntity
            .status(HttpStatus.CREATED)                 
            .body(this.userService.chkCredentials(accessKey, secretKey, timestamp));
    }
    catch(ChekingCredentialsFailedException e) {
        e.printStackTrace(); // see note 2
        return ResponseEntity
            .status(HttpStatus.FORBIDDEN)
            .body("Error Message");
    }
}

Note 1: You don't have to use the ResponseEntity builder but I find it helps with keeping the code readable. It also helps remembering, which data a response for a specific HTTP status code should include. For example, a response with the status code 201 should contain a link to the newly created resource in the Location header (see Status Code Definitions). This is why Spring offers the convenient build method ResponseEntity.created(URI).

Note 2: Don't use printStackTrace(), use a logger instead.

Provide an @ExceptionHandler

Remove the try-catch block from your method and let it throw the exception. Then create another method in a class annotated with @ControllerAdvice like this:

@ControllerAdvice
public class ExceptionHandlerAdvice {

    @ExceptionHandler(ChekingCredentialsFailedException.class)
    public ResponseEntity handleException(ChekingCredentialsFailedException e) {
        // log exception
        return ResponseEntity
                .status(HttpStatus.FORBIDDEN)
                .body("Error Message");
    }        
}

Note that methods which are annotated with @ExceptionHandler are allowed to have very flexible signatures. See the Javadoc for details.