9.线程通信wait、notify

线程之间通信

1.线程是操作系统的独立的个体，但这些个体如果不经过特殊处理就不能成为一个整体。

2.使用wait、notify，方法实现线程通信(2个方法都是需要object方法)

3.wait(释放锁)、notify(不会释放锁)必须配合synchronized关键字使用。

package demo2;
import java.util.ArrayList;
import java.util.List;
/**
 * Created by liudan on 2017/7/4.
 */
public class MyThread2_2 {
    private volatile static List<String> lsit = new ArrayList<String>();
    public void add() {
        lsit.add("add......");
    }
    public int size() {
        return lsit.size();
    }
    public static void main(String[] args) {
        final MyThread2_1 myThread2_1 = new MyThread2_1();
        final Object o = new Object();
        Thread t1 = new Thread(new Runnable() {
            @Override
            public void run() {
                synchronized (o) {
                    try {
                        for (int i = 0; i < 10; i++) {
                            myThread2_1.add();
                            System.err.println("当前线程：" + Thread.currentThread().getName() + "添加了一个元素");
                            Thread.sleep(500);
                            if (myThread2_1.size() == 5) {
                                System.err.println("发起通知");
                                o.notify();
                            }
                        }
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            }
        }, "t1");
        Thread t2 = new Thread(new Runnable() {
            @Override
            public void run() {
                synchronized (o) {
                        if (myThread2_1.size()!= 5) {
                            System.err.println("t2 进入");
                            try {
                                o.wait();
                            } catch (InterruptedException e) {
                                e.printStackTrace();
                            }
                        }
                        System.err.println("当前线程：" + Thread.currentThread().getName() + "收到通知...");
                }
            }
        }, "t2");
        t2.start();
        t1.start();
    }
}

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