Java多线程同步问题：信号量示例-蒲公英云

Java多线程同步问题：信号量示例

在Java中，信号量（Semaphore）是一种多线程同步工具。它能控制同时访问共享资源的线程数量。

下面是一个简单的信号量示例：

import java.util.concurrent.Semaphore;
public class SemaphoreExample {
    private Semaphore semaphore = new Semaphore(1); // 初始化为允许1个线程
    public void threadOne() throws InterruptedException {
        System.out.println("Thread 1: Trying to acquire lock...");
        semaphore.acquire(); // 获取锁
        System.out.println("Thread 1: Lock acquired, executing task...");
        doSomething();
        System.out.println("Thread 1: Lock released back to semaphore.");
        semaphore.release(); // 释放锁
    }
    public void threadTwo() throws InterruptedException {
        System.out.println("Thread 2: Trying to acquire lock...");
        semaphore.acquire(); // 获取锁
        System.out.println("Thread 2: Lock acquired, executing task...");
        doSomethingElse();
        System.out.println("Thread 2: Lock released back to semaphore.");
        semaphore.release(); // 释放锁
    }
    public void startThreads() throws InterruptedException {
        new Thread(threadOne)).start(); // 启动线程1
        new Thread(threadTwo)).start(); // 启动线程2
    }
    private void doSomething() { // 你的任务，这里只是一个示例
        try {
            Thread.sleep(500); // 模拟一些耗时操作
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println("Thread 1: Operation completed.");
    }
    private void doSomethingElse() { // 另一个任务，这里只是一个示例
        try {
            Thread.sleep(300); // 模拟一些耗时操作
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println("Thread 2: Operation completed.");
    }
    public static void main(String[] args) throws InterruptedException {
        SemaphoreExample example = new SemaphoreExample();
        example.startThreads(); // 启动线程
    }
}