编写一个多线程，实现控制台依次输出101010..._创建两个线程将connter中的 count 依次 +1 -1 最终输出 10101010...-优快云博客

本文链接：https://blog.youkuaiyun.com/qingcyb/article/details/120404806

本文通过一个具体的Java程序示例，介绍了如何使用synchronized关键字来实现线程间的同步操作，确保了线程安全。示例中包含了一个共享资源类MyObject及对应的增加和减少线程，演示了线程间等待和通知机制。

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1、MyObject

public class MyObject {
    private int counter;

    public synchronized void increase(){
        if (counter != 0) {
            try {
                wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        counter++;
        System.out.print(counter);
        notify();
    }

    public synchronized void decrease(){
        if(counter == 0) {
            try {
                wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        counter--;
        System.out.print(counter);
        notify();
    }
}

2、IncreaseThread

public class IncreaseThread extends Thread {
    private MyObject myObject;

    public IncreaseThread(MyObject myObject) {
        this.myObject = myObject;
    }

    @Override
    public void run(){
        for (int i = 0; i < 30; i++) {
            try {
                Thread.sleep((long) (Math.random() * 1000));
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            myObject.increase();
        }
    }
}

3、DecreaseThread

public class DecreaseThread extends Thread {
    private MyObject myObject;

    public DecreaseThread(MyObject myObject) {
        this.myObject = myObject;
    }

    @Override
    public void run() {
        for (int i = 0; i < 30; i++) {
            try {
                Thread.sleep((long)(Math.random() * 1000));
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            myObject.decrease();
        }
    }
}

4、测试类

public class MyTest {
    public static void main(String [] args) {
        MyObject myObject = new MyObject();
        IncreaseThread increaseThread = new IncreaseThread(myObject);
        DecreaseThread decreaseThread = new DecreaseThread(myObject);
        increaseThread.start();
        decreaseThread.start();
    }
}

// 输出结果：

101010101010101010101010101010101010101010101010101010101010

5、扩展

如果两个增的线程，两个减的线程，需要将MyObject类中的方法，if判断改为while