Java并发工具类性能对比与案例解析-蒲公英云

Java并发工具类性能对比与案例解析

Java并发工具类主要包括java.util.concurrent包中的各种类，如ExecutorService（线程池）、Thread、CountDownLatch、Semaphore等。

下面我们将通过性能对比和案例解析来展示这些工具的使用场景和性能特点：

线程池对比：`
ExecutorService fixedThreadPool = Executors.newFixedThreadPool(5);
ExecutorService queueThreadPool = Executors.newCachedThreadPool();

// 并发任务
for (int i = 0; i < 10; i++) {
```
 fixedThreadPool.execute(() -> System.out.println("Fixed: " + i)));
 queueThreadPool.execute(() -> System.out.println("Caching: " + i)));
```
}

// 关闭线程池
fixedThreadPool.shutdown();
queueThreadPool.shutdown();

// 确保所有任务完成
while (!fixedThreadPool.isTerminated() || !queueThreadPool.isTerminated())) {
```
 try {
     Thread.sleep(100);
 } catch (InterruptedException e) {
     e.printStackTrace();
 }
```
}
`
案例解析：使用CountDownLatch来协调多个线程的执行：

import java.util.concurrent.CountDownLatch;
public class CountDownLatchExample {
    private final CountDownLatch countDownLatch = new CountDownLatch(3);
    public void runThreads() {
        // 创建三个线程，每个线程增加计数器一次
        Thread thread1 = new Thread(() -> countDownLatch.countDown()));
        Thread thread2 = new Thread(() -> countDownLatch.countDown()));
        Thread thread3 = new Thread(() -> countDownLatch.countDown()));
        // 启动线程
        thread1.start();
        thread2.start();
        thread3.start();
        try {
            // 等待所有计数器下降到零
            countDownLatch.await();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
    public static void main(String[] args) {
        CountDownLatchExample example = new CountDownLatchExample();
        example.runThreads();
    }
}