Question

I used a lot annotations in java but I never wrote one. I read though several guides and I am really confused.

They are using annotations like meta information eg names, age etc. That is really confusing because I want to do something different

http://www.developer.com/java/other/article.php/3556176/An-Introduction-to-Java-Annotations.htm

I want to control the function calls.

for example

@Permission(user)
public static void account(){
...
} 

So my functions only gets called if the user has the permission, otherwise the user should be redirected to the login page.

I could not find any information, maybe I am using the wrong keyword?

I hope you can clear things up,

Thanks.

Answer 1

You can do that, but with a lot of extra code. Intercepting method calls is part of AOP (aspect oriented programming). You need to make proxies of you target objects, and in the invocation handler parse the annotation.

Luckily, you don’t have to do that – since you have a webapp, just use spring/spring-mvc/spring-security. Spring gives you an AOP framework that you can use to define aspects handling your permission logic