Package/Endpoint/Controller Layer Exception Handling Design

Question

So here is my requirement to handle component/package-specific exceptions. for example for package A, BAD Request should return spring default bad request-response, but for package B it should return custom response.

Answer 1

You can specify the handled controller by this way:

@ControllerAdvice(assignableTypes = {MyController.class})
public class CoreExceptionHandler {
 ....
 ....
 ....
}

Answer 2

You can specify the behaviour for specific exceptions thrown from your code using an @ExceptionHandler. Also, you can limit your exception handlers to specific packages:

@ControllerAdvice(package = "com.example.b")
public class PackageBErrorHandler {

    @ResponseStatus(BAD_REQUEST)
    @ExceptionHandler
    @ResponseBody
    public ErrorDto handleValidationError(ConstraintValidationException e) {
        return ...; //build your custom response here
    }
}