How return error message in spring mvc @Controller
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.");
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.