Java Thread notifyAll()用法及代码示例

线程类的 notifyAll() 方法用于唤醒所有线程。此方法向特定对象的所有等待线程提供通知。

如果我们使用 notifyAll() 方法并且有多个线程在等待通知，那么所有线程都收到了通知，但是线程的执行将一个一个地执行，因为线程需要一个锁，而一个对象只有一个锁可用。

用法

public final void notifyAll()

此方法不返回任何值。

异常

IllegalMonitorStateException：如果当前线程不是对象监视器的所有者，则抛出此异常。

示例

class Notify1 extends Thread 
{
    public void run()
    {
        synchronized(this)
        {
            System.out.println("Starting of " + Thread.currentThread().getName());
            try {
                this.wait();
            }
            catch (InterruptedException e) {
                e.printStackTrace();}
            System.out.println(Thread.currentThread().getName() + "...notified");
        }
    }
}
class Notify2 extends Thread {
    Notify1 notify1;
    Notify2(Notify1 notify1)
    {
        this.notify1 = notify1;
    }
    public void run()
    {
        synchronized(this.notify1)
        {
            System.out.println("Starting of " + Thread.currentThread().getName());
            try {
                this.notify1.wait();
            }
            catch (InterruptedException e) {
                e.printStackTrace();
            }
            System.out.println(Thread.currentThread().getName() + "...notified");
        }
    }
} 
class Notify3 extends Thread 
{
    Notify1 notify1;
    Notify3(Notify1 notify1)
    {
        this.notify1 = notify1;
    }
    public void run()
    {
        synchronized(this.notify1)
        {
            System.out.println("Starting of " + Thread.currentThread().getName());
            // call the notifyAll() method
            this.notify1.notifyAll();
            System.out.println(Thread.currentThread().getName() + "...notified");
        }
    }
}
public class JavaNotifyAllExp 
{
    public static void main(String[] args) throws InterruptedException
    {
        Notify1 notify1 = new Notify1();
        Notify2 notify2 = new Notify2(notify1);
        Notify3 notify3 = new Notify3(notify1);
        
        // creating the threads 
        Thread t1 = new Thread(notify1, "Thread-1");
        Thread t2 = new Thread(notify2, "Thread-2");
        Thread t3 = new Thread(notify3, "Thread-3");
        
        // call run() method
        t1.start();
        t2.start();
        Thread.sleep(100);
        t3.start();
    }
}

输出：

Starting of Thread-1
Starting of Thread-2
Starting of Thread-3
Thread-3...notified
Thread-2...notified
Thread-1...notified

相关用法

注：本文由纯净天空筛选整理自 Java Thread notifyAll() method。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。