JAVA设计模式之状态模式（state）

package com.srr.dp.state;

/**
 * 我的女朋友有很多种状态
 * 当给我的女朋友添加新的状态的时候下面所有方法的swith语句中都需要添加新的分支判断
 * 简而言之，这种实现方式当增加新的状态时非常不方便
 */
public class GirFriend {

    private String name;
    private enum State {HAPPY,NORMAL}
    private State state;

    private void smile(){
        switch (state){
            case HAPPY:
                System.out.println("哈哈哈大笑");
                break;
            case NORMAL:
                System.out.println("微微一笑");
            default:
                System.out.println();
        }
    }

    private void cry(){
        switch (state){
            case HAPPY:
                System.out.println("笑中带泪，感动的哭泣");
                break;
            case NORMAL:
                System.out.println("哇哇哭泣");
                break;
            default:
                System.out.println();
        }
    }

    private void say(){
        switch (state){
            case HAPPY:
                System.out.println("侃侃而谈，风趣幽默");
                break;
            case NORMAL:
                System.out.println("沉默寡言，很少说话");
            default:
                System.out.println();
        }
    }

}

package com.srr.dp.state;

/**
 * 状态抽象类
 */
abstract public class State {
    abstract void smile();
    abstract void cry();
    abstract void say();
}

package com.srr.dp.state;

/**
 * 女朋友的正常状态
 */
public class NormalState extends State {
    @Override
    void smile() {
        System.out.println("微微一笑");
    }

    @Override
    void cry() {
        System.out.println("哇哇哭泣");
    }

    @Override
    void say() {
        System.out.println("沉默寡言，很少说话");
    }
}

package com.srr.dp.state;

/**
 * 女朋友高兴状态
 */
public class HappyState extends State {
    @Override
    void smile() {
        System.out.println("哈哈哈大笑");
    }

    @Override
    void cry() {
        System.out.println("笑中带泪，感动的哭泣");
    }

    @Override
    void say() {
        System.out.println("侃侃而谈，风趣幽默");
    }
}

package com.srr.dp.state;

/**
 * 当添加新的状态的时候只需要添加新的状态类继承抽象state类
 */
public class GirFriend2 {

    private String name;
    private State state;

    public GirFriend2(String name,State state){
        this.name = name;
        this.state = state;
    }

    public void smile(){
        state.smile();
    }

    public void cry(){
        state.cry();
    }

    public void say(){
        state.say();
    }

}

package com.srr.dp.state;

/**
 * 测试类
 */
public class T {
    public static void main(String[] args) {
        State state = new HappyState();
        GirFriend2 girFriend = new GirFriend2("程潇",state);
        girFriend.smile();
        girFriend.cry();
        girFriend.say();
    }

}