JUC学习之线程通信小Demo_jucdemo-优快云博客

本文链接：https://blog.youkuaiyun.com/qq_34560242/article/details/81168486

本文通过一个实例演示了如何使用Java并发库（JUC）实现线程A、B、C之间的通信，以确保它们按顺序打印，循环五轮。这个例子深入探讨了Java中的线程同步和通信机制。

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按照顺序打印线程A、B、C，共打印五轮：

public class Test {

    public static void main(String[] args) {
        AlternatePrinting printing = new AlternatePrinting();
        new Thread(() -> {
            for (int i = 1; i <= 5; i++) {
                try {
                    printing.method1(i);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }, "A").start();

        new Thread(() -> {
            for (int i = 1; i <= 5; i++) {
                try {
                    printing.method2(i);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }, "B").start();

        new Thread(() -> {
            for (int i = 1; i <= 5; i++) {
                try {
                    printing.method3(i);
                    System.out.println("<------------我是可爱的分割线------------->");
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }, "C").start();
    }
}

class AlternatePrinting {

    private int number = 1;
    private Lock lock = new ReentrantLock();
    private Condition condition1 = lock.newCondition();
    private Condition condition2 = lock.newCondition();
    private Condition condition3 = lock.newCondition();

    public void method1(int time) throws Exception {
        lock.lock();
        try {
            if (number != 1) {
                    condition1.await();
            }
            System.out.println(Thread.currentThread().getName() + "\t" + time);
            number = 2;
            // 唤醒2
            condition2.signal();
        } finally {
            lock.unlock();
        }
    }

    public void method2(int time) throws Exception {
        lock.lock();
        try {
            if (number != 2) {
                condition2.await();
            }
            System.out.println(Thread.currentThread().getName() + "\t" + time);
            number = 3;
            // 唤醒3
            condition3.signal();
        } finally {
            lock.unlock();
        }
    }

    public void method3(int time) throws Exception {
        lock.lock();
        try {
            if (number != 3) {
                condition3.await();
            }
            System.out.println(Thread.currentThread().getName() + "\t" + time);
            number = 1;
            // 唤醒1
            condition1.signal();
        } finally {
            lock.unlock();
        }
    }
}