Java在参数注释上执行代码

Question

I am very new to Java annotations. But, how I understand is that they can't run any code them selves.

I am trying to make a validation package and would like to use the @valid parameter annotation to validate an object.
Example:

public Response login(@valid LoginRequest request) {
    return ...
}

I would like it to work this way, it is the same way as in spring validating.

So my question is: How can I execute code on the @valid annotation to validate an object? I don't mind if the solution would only work with spring.

The reason I want to make my own validation package is because I want to have a more "laravel like" validation package.

Answer 1

It was pretty easy. I just had to create an interceptor and check in the preHandle if there was an handler parameter that had the @valid annotation.

If @valid was present I could get the object and validate it, when failed just throw an exception and handle the exception with the exception handler.

I didn't know that I could access controller parameters from an interceptor...