package statePattern;

/**
 * @author ：dazhu
 * @date ：Created in 2020/4/3 16:38
 * @description：
 * @modified By：
 * @version: $
 */
//主类
public class Main {
    public static void main(String[]args){
        State1 s1 = new State1();
        StateHolder sh = new StateHolder(s1);
        sh.disPlay();

        //不断地请求，不断地展示
        sh.changeState();
        sh.disPlay();

        sh.changeState();
        sh.disPlay();

        sh.changeState();
        sh.disPlay();

        sh.changeState();
        sh.disPlay();
    }
}
//接口类
/**
 * 状态的接口，所有不同的状态都要实现这个接口
 * 接口里有什么尼？
 */
public interface State {
    public  void showSelf();
    public void Handle(StateHolder sh);
}
//状态类
public class State1 implements State{

    @Override
    public void Handle(StateHolder sh) {
        sh.state = new State2();
    }

    @Override
    public void showSelf() {
        System.out.println("State1");
    }
}
public class State2 implements State{
    @Override
    public void Handle(StateHolder sh) {
        sh.state = new State3();
    }

    @Override
    public void showSelf() {
        System.out.println("State2");
    }
}
public class State3 implements State{
    @Override
    public void Handle(StateHolder sh) {
        sh.state = new State4();
    }

    @Override
    public void showSelf() {
        System.out.println("State3");
    }
}
public class State4 implements State{

    @Override
    public void Handle(StateHolder sh) {
        sh.state = new State1();
    }
    @Override
    public void showSelf() {
        System.out.println("State4");
    }
}
//状态拥有者
public class StateHolder {
    public State state = null;
    //构造方法，用来初始化状态持有则，
    public StateHolder(State state){
        this.state = state;
    }


    //切换自己的状态
    public void changeState(){
        state.Handle(this);
    }

    //显示自己的状态
    public void disPlay(){
        state.showSelf();
    }
}