JAVA设计模式（行为型）------ 状态模式

允许对象在内部状态发生改变时改变它的行为，对象看起来好像修改了它的类。
类的行为是基于它的状态改变的。

public class State_Main {
    public static void main(String[] args){
        Person person = new Person();
        Thread thr = new Thread(()->{
            person.start();
        });
        Thread thread = new Thread(()->{
            try {
            State eat_state = new EatState();
            person.setState(eat_state);
            Thread.sleep(4000);
            State drink_state = new DrinkState();
            person.setState(drink_state);
            Thread.sleep(4000);
            State stop_state = new StopState();
            person.setState(stop_state);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        });
        thr.start();
        thread.start();
    }
}

interface State{
    void action();
    String getState();
}

enum StateEnum{
    EAT("eat"),
    DRINK("drink"),
    STOP("stop");
    private String code;
    StateEnum(String code) {
        this.code = code;
    }
    public String getCode() {
        return code;
    }
}
class EatState implements State{
    private String state = StateEnum.EAT.getCode();
    @Override
    public void action() {
        System.out.println("EatState...doEat...吃饭中...");
    }
    @Override
    public String getState() {
        return state;
    }

}
class DrinkState implements State{
    private String state = StateEnum.DRINK.getCode();
    @Override
    public void action() {
        System.out.println("DrinkState...doDrink...喝水中...");
    }
    @Override
    public String getState() {
        return state;
    }
}
class StopState implements State{
    private String state = StateEnum.STOP.getCode();
    @Override
    public void action() {
        System.out.println("停止...去休息");
    }
    @Override
    public String getState() {
        return state;
    }
}
@Data
class Person {

    private State state;

    public Person() {
    }

    public void start(){
        while (true){
            if (state != null && StateEnum.STOP.getCode().equals(state.getState())){
                state.action();
                return;
            }else if (state != null && !StateEnum.STOP.getCode().equals(state.getState())){
                state.action();
            }
        }
    }
    public void setState(State state) {
        this.state = state;
    }
}