Chain of responsibility

package chainofresponsibility.model.handler;

public abstract class Handler {

    private Handler     next;

    public Handler (){

    }

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

    public void handleRequest (){
        if (this.next != null){
            this.next.handleRequest();
        }
        this.start();
    }

    public abstract void start();

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

    public Handler getNext (){
        return this.next;
    }

}