/**
 *
 * @author Mutasem
 */
public class Request {
    
}

/************************************/
public abstract class Handler {
    public abstract void handle(Request request);
    protected Handler next;

    public Handler(Handler next) {
        this.next = next;
    }
    
}

/************************************/
public class AntiDoSHandler extends Handler {

    public AntiDoSHandler(Handler next) {
        super(next);
    }

    @Override
    public void handle(Request request) {
        //Anti DoS logic
        next.handle(request);
    }

}

/*******************************************/
public class AuthenticationHandler extends Handler{

    public AuthenticationHandler(Handler next) {
        super(next);
    }

    @Override
    public void handle(Request request) {
        //Authentication logic
        next.handle(request);
    }
    
}

/********************************************/
public class AuthorizationHandler extends Handler{

    public AuthorizationHandler(Handler next) {
        super(next);
    }

    @Override
    public void handle(Request request) {
        //Authorization logic
        next.handle(request);
    }
    
}

/********************************************/
public class WebApp {

    AuthorizationHandler authorizationHandler;
    AuthenticationHandler authenticationHandler;
    AntiDoSHandler antiDoSHandler;

    public WebApp() {

    }

    private void startUp() {
        authorizationHandler = new AuthorizationHandler(null);
        authenticationHandler = new AuthenticationHandler(authorizationHandler);
        antiDoSHandler = new AntiDoSHandler(authenticationHandler);
    }
    public void recieve(Request request){
    antiDoSHandler.handle(request);
    }

}