设计模式

职责链模式

一个请求,沿链传递直到有一个Handler对象处理它.
接收者和发送者都没有对方的明确信息,且链中的对象自己也不知道链的结构.结果是职责链可以简化对象的相互连接,它们仅需保持一个指向其后继者的引用,而不需保持它所有的候选接收者的引用.
随时地增加或修改处理一个请求的结构.增强了给对象指派职责的灵活性.

注意: 一个请求极有可能到了链的末端都得不到处理,或者因为没有正确配置而得不到处理.这是很糟糕的

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package chain.of.responsibility;

/**
 * Created by hero on 17-2-20.
 */
public abstract class Manager {
    protected Manager superior;

    public void setSuperior(Manager superior) {
        this.superior = superior;
    }

    public abstract void handle(int money);
}

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package chain.of.responsibility;

/**
 * Created by hero on 17-2-20.
 */
public class Minister extends Manager {

    @Override
    public void handle(int money) {
        if (money < 100) {
            System.out.println("ok, give you.");
        } else {
            if (superior != null) {
                superior.handle(money);
            }
        }
    }
}

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package chain.of.responsibility;

/**
 * Created by hero on 17-2-20.
 */
public class President extends Manager {

    @Override
    public void handle(int money) {
        System.out.println("没有我管不了,OK.");
    }
}

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package chain.of.responsibility;

/**
 * Created by hero on 17-2-20.
 */
public class Main {
    public static void main(String[] args) {
        Minister minister = new Minister();
        President president = new President();
        minister.setSuperior(president);

        int[] money = {10, 20, 120};

        for (int m : money) {
            minister.handle(m);
        }
    }
}