java | 设计模式 同步模式 交替输出 wait & notify

这里的原理类似链表。

记录下一个的执行 flag，只有 flag 相同的时候，才会执行。

package com.redisc;

import lombok.extern.slf4j.Slf4j;

@Slf4j(topic = "c.Run")
public class Run {

public static void main(String[] args) throws Exception {

WaitNotify wn = new WaitNotify(1, 5);

new Thread(() -> {
            wn.print("a", 1, 2);
        }).start();
        new Thread(() -> {
            wn.print("b", 2, 3);
        }).start();
        new Thread(() -> {
            wn.print("c", 3, 1);
        }).start();
    }

}

class WaitNotify {

private int flag;
    private int loopNumber;

public WaitNotify(int flag, int loopNumber) {
        this.flag = flag;
        this.loopNumber = loopNumber;
    }

public void print(String str, int waitFlag, int nextFlag) {
        for (int i = 0; i < loopNumber; i++) {
            synchronized (this) {
                while (flag != waitFlag) {
                    try {
                        this.wait();
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
                System.out.println(str);
                flag = nextFlag;
                this.notifyAll();
            }
        }
    }
}

a
b
c
a
b
c
a
b
c
a
b
c
a
b
c