java 两个线程

简介

使用synchronized, 来实现两个线程的同步操作.

参考链接

https://www.cnblogs.com/leihuazhe/p/7898563.html

TIPS

    唤醒一个在等待资源的线程.
    public final native void notify();
    阻塞资源, 等待被唤醒.
    public final void wait() throws InterruptedException {
        wait(0);
    }

Synchronized 锁的对象是方法的调用者, 两个方法用的是同一个锁, 谁先拿到谁先执行

code

/**
 * Created by lee on 2021/6/21.
 */
public class Add {
    public synchronized void  one() throws InterruptedException {
        boolean flag = true;
        while(flag) {
            for(int i = 1; i<=99; i+=2) {
                System.out.println(Thread.currentThread().getName()+ " i " + i);
                if(i == 99) {
                    flag = false;
                    this.notify();
                    break;
                }
                this.notify();
                this.wait();
            }
        }
    }
    public synchronized void two() throws  InterruptedException {
        boolean flag = true;
        while(flag) {
            for(int i = 2; i<=100; i+=2) {
                System.out.println(Thread.currentThread().getName()+ " i " + i);
                if(i == 100) {
                    flag = false;
                    this.notify();
                    break;
                }
                this.notify();
                this.wait();
            }
        }
    }

    public static void main(String[] args) {
        Add a = new Add();

        new Thread(()->{
            try {
                a.one();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        },"A").start();

        new Thread(()->{
            try {
                a.two();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        },"B").start();
    }
}

结果

B i 98
A i 99
B i 100