指责链模式

public class 职责链模式 {
    public static void main(String[] args) {
        Handler h1 = new ConcreteHandler1();
        Handler h2 = new ConcreteHandler2();
        Handler h3 = new ConcreteHandler3();
        h1.SetSuccessor(h2);
        h2.SetSuccessor(h3);
        
        int[] request = {5, 15, 25, 35};
        
        for(int i : request) 
            h1.HandleRequest(i);
    }
}
class Handler {
    protected Handler successor;
        
    public void SetSuccessor(Handler successor) {
        this.successor = successor;
    }
    
    public void HandleRequest(int request) {}
}

class ConcreteHandler1 extends Handler {
    public void HandleRequest(int request) {
        if(request >= 0 && request < 10) {
            System.out.println("ConcreteHandler1 handle request " + request);
        } 
        else {
            if (successor != null) {
                successor.HandleRequest(request);
            } else {
                System.out.println("Request " + request + " is unhandled");
            }
        }
    }
}

class ConcreteHandler2 extends Handler {
    public void HandleRequest(int request) {
        if(request >= 10 && request < 20) {
            System.out.println("ConcreteHandler2 handle request " + request);
        } 
        else {
            if (successor != null) {
                successor.HandleRequest(request);
            } else {
                System.out.println("Request " + request + " is unhandled");
            }
        }
    }
}

class ConcreteHandler3 extends Handler {
    public void HandleRequest(int request) {
        if(request >= 20 && request < 30) {
            System.out.println("ConcreteHandler3 handle request " + request);
        } 
        else {
            if (successor != null) {
                successor.HandleRequest(request);
            } else {
                System.out.println("Request " + request + " is unhandled");
            }
        }
    }
}