REST Exception Handling

@ControllerAdvice + @ExceptionHandler lets you turn exceptions into consistent, clean JSON error responses across every controller.

@ControllerAdvice
public class ApiExceptionHandler {

    @ExceptionHandler(ResourceNotFoundException.class)
    public ResponseEntity<ErrorResponse> handleNotFound(ResourceNotFoundException ex) {
        return ResponseEntity.status(HttpStatus.NOT_FOUND)
            .body(new ErrorResponse(ex.getMessage()));
    }
}

Tip

Mention @RestControllerAdvice too — same idea, but return values are auto-serialized to JSON like @RestController.