今天来讲一个悲伤的故事，关于小明找小红的故事。加班狗小明某日不用加班，开开心心把家还，结果妻子小红不在家，发生了下面的一幕：

上代码。首先定义好小红

public interface Lover {
}

小红：

public class WifeHong implements Lover {
    public WifeHong(Affairs affairs) {
        System.out.println("我是小红，去" + affairs.name + "家。");
        affairs.setLover(this);
    }
}

处理请求抽象类：

public abstract class Affairs {

    protected Affairs nextOne;
    protected String name;
    protected Lover lover;

    protected Affairs(String name) {
        this.name = name;
    }

    public abstract void handleRequest(Lover lover);

    public void setLover(Lover lover) {
        this.lover = lover;
    }

    public void setNextOne(Affairs nextOne) {
        this.nextOne = nextOne;
    }

    public Affairs getNextOne() {
        return nextOne;
    }
}

具体处理请求类：

public class OldMan extends Affairs {

    public OldMan(String name) {
        super(name);
    }

    @Override
    public void handleRequest(Lover _lover) {
        System.out.println("==============================");
        System.out.println("咚咚咚... " + name + " ,我来找小红。");
        if (lover == null)
            System.out.println("[" + name + "]我不认识，走开。");
        else if (lover.equals(_lover))
            System.out.println("[" + name + "]pia pia pia...");

        if (nextOne == null)
            System.out.println("[" + name + "]回家吧，小明，听大哥的话。");
        else {
            System.out.println("[" + name + "]去别人家找去，跟我没关系。");
            nextOne.handleRequest(_lover);
        }
    }
}

请求者小明：

public class XiaoMing {
    public static void main(String[] args) {
        OldMan oldLi = new OldMan("老李");
        OldMan oldZhou = new OldMan("老周");
        OldMan oldWang = new OldMan("老王");
        Lover xiaoHong = new WifeHong(oldWang);
        oldLi.setNextOne(oldZhou);
        oldZhou.setNextOne(oldWang);
        oldLi.handleRequest(xiaoHong);
    }
}

执行结果，真相大白：

后话：关于责任链，就在于这个handleRequest方法，其他东西都是情节需要，自行演绎。（^_^）