Spring 引导：无法在 @ControllerAdvice 中捕获异常

Question

I have 2 exception handler classes annotated with @RestControllerAdvice and:

I use the first one as global exception handler to catch exceptions:

@RestControllerAdvice
public class GlobalExceptionHandler extends ResponseEntityExceptionHandler {

    @Override
    @ResponseStatus(HttpStatus.UNPROCESSABLE_ENTITY)
    protected ResponseEntity<Object> handleMethodArgumentNotValid(...) {
      // ...
    }

    @ExceptionHandler(Exception.class)
    @ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)
    public ResponseEntity<Object> handleAllUncaughtException(Exception ex, WebRequest request) {
        // ...
    }

    // code omitted for clarity
}

and the second for validation exceptions (I creates custom validation):

@RestControllerAdvice
public class ValidationExceptionHandler { // did not extend from extends ResponseEntityExceptionHandler

    @ExceptionHandler(ConstraintViolationException.class)
    @ResponseStatus(HttpStatus.UNPROCESSABLE_ENTITY)
    protected ValidationErrorResponse onConstraintValidationException(ConstraintViolationException e) {
        // ...
    }
}

When I move onConstraintValidationException to GlobalExceptionHandler class, I catch validation exception and display corresponding message. But when it is in the second ControllerAdvice class ( ValidationExceptionHandler ) as shown above, code does not hit onConstraintValidationException method.

I also tried to extend the second class from ResponseEntityExceptionHandler , but does not make any sense.

So, what is the problem and how can I fix it?

Answer 1

In your case it could be question of priorities... The first exception handler has highest priority, and probably the handleAllUncaughtException is going to capture all the exceptions.

For catching the ConstraintViolationException in the second handler (ValidationExceptionHandler) you should give to it the highest priority, like so:

@RestControllerAdvice
@Order(Ordered.HIGHEST_PRECEDENCE)
public class ValidationExceptionHandler { 

and to the first one lowest:

@RestControllerAdvice
@Order(Ordered.LOWEST_PRECEDENCE)
public class GlobalExceptionHandler extends ResponseEntityExceptionHandler {

Can have a look at this discussion, it can be interesting to learn more about how it works and have some alternative solutions: Setting Precedence of Multiple @ControllerAdvice @ExceptionHandlers