Java 线程池代码例子

以下是一个 Java 线程池的代码例子：

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class ThreadPoolExample {
    public static void main(String[] args) {
        ExecutorService executor = Executors.newFixedThreadPool(5);
        for (int i = 0; i < 10; i++) {
            Runnable worker = new WorkerThread("" + i);
            executor.execute(worker);
        }
        executor.shutdown();
        while (!executor.isTerminated()) {
        }
        System.out.println("Finished all threads");
    }
}

class WorkerThread implements Runnable {
    private String message;

    public WorkerThread(String s) {
        this.message = s;
    }

    public void run() {
        System.out.println(Thread.currentThread().getName() + " (Start) message = " + message);
        processMessage();
        System.out.println(Thread.currentThread().getName() + " (End)");
    }

    private void processMessage() {
        try {
            Thread.sleep(2000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}

这个例子创建了一个固定大小为 5 的线程池，然后提交了 10 个任务给线程池执行。每个任务都是一个 WorkerThread 对象，它会打印出自己的编号，然后休眠 2 秒钟。最后，主线程等待所有任务执行完毕后输出 "Finished all threads"。