多线程交互
在Java中，可以使用synchronized关键字或者java.util.concurrent包中的
ReentrantLock来实现多线程交替打印。
方式一：synchronized
public class ThreadJH_Synchronized {public static void main(String[] args) {ExecutorService executorService = Executors.newFixedThreadPool(2);executorService.submit(ThreadJH_Synchronized::threadTwo);executorService.submit(ThreadJH_Synchronized::threadOne);executorService.shutdown();}private static Integer count = 0;private static Object lockObject = new Object();private static void threadOne() {while (count < 10) {synchronized (lockObject) {if (count >= 10) {return;}Util.mySleep(100);Util.printfLog("thread 1,current count=" + count);count++;//用于唤醒一个在此对象监视器上等待的线程。lockObject.notify();try {//判断ccount 小于等于满足条件才进入等待。如果不增加判断线程无法结束线程，会死锁if (count < 10) {//让当前线程进入等待状态。直到其他线程调用此对象的 notify() 方法或 notifyAll() 方法。lockObject.wait();}} catch (InterruptedException e) {throw new RuntimeException(e);}}}}private static void threadTwo() {while (count < 10) {synchronized (lockObject) {if (count >= 10) {return;}Util.mySleep(100);Util.printfLog("thread 2,current count=" + count);count++;//用于唤醒一个在此对象监视器上等待的线程。lockObject.notify();try {if (count < 10) {//让当前线程进入等待状态。直到其他线程调用此对象的 notify() 方法或 notifyAll() 方法。lockObject.wait();}} catch (InterruptedException e) {throw new RuntimeException(e);}}}}
}方式二：ReentrantLock
public class ThreadJH_ReentrantLock {public static void main(String[] args) {ExecutorService executorService = Executors.newFixedThreadPool(2);executorService.submit(ThreadJH_ReentrantLock::threadOne);executorService.submit(ThreadJH_ReentrantLock::threadTwo);executorService.shutdown();}private static Integer count = 0;private static ReentrantLock lock = new ReentrantLock();//定义了两个`Condition`对象`condition1`和`condition2`，它们用于线程间的协调/通信。private static final Condition condition1 = lock.newCondition();private static final Condition condition2 = lock.newCondition();private static void threadOne() {while (count < 10) {lock.lock();if (count >= 10) {return;}try {Util.mySleep(100);Util.printfLog("thread 1,current count=" + count);count++;//唤醒等待：// 如果有任何线程正在等待与 `condition2` 关联的 `Lock` 上的 `condition2.await();`，则调用 `signal()` 方法会选择其中一个线程（如果有多个线程在等待）并通知它可以继续执行condition2.signal();//判断ccount 小于满足条件才进入等待。如果不增加判断线程无法结束线程，会死锁if (count < 10) {//当前线程释放锁，等待// 调用`await()`方法的线程会释放与`Condition`关联的`Lock`，允许其他线程获得这个锁并执行它们的任务。condition1.await();}} catch (Exception e) {throw new RuntimeException(e);} finally {lock.unlock();}}}private static void threadTwo() {while (count < 10) {lock.lock();if (count >= 10) {return;}try {Util.mySleep(100);Util.printfLog("thread 2,current count=" + count);count++;//唤醒等待：condition1.signal();if (count < 10) {//当前线程释放锁，等待condition2.await();}} catch (Exception e) {throw new RuntimeException(e);} finally {lock.unlock();}}}
}
参考：
Java多线程交替打印_java 多线程交替打印-CSDN博客