Interceptor design pattern is used for intercepting a request. Primary

use of this pattern is in Security policy implementation.

We can use this pattern to intercept the requests by a client to a

resource. At the interception we can check for authentication and

authorization of client for the resource being accessed.

In Java it is used in javax.servlet.Filter interface.

This pattern is also used in Spring framework in HandlerInterceptor

and MVC interceptor.

https://www.tutorialspoint.com/design_pattern/intercepting_filter_pattern.htm