Java中线程的4种创建方式

1. 继承Thread类

public class ThreadDemo {
    public static void main(String[] args) {
        MyThread myThread = new MyThread();
        Thread t = new Thread(myThread);
        t.start();
        System.out.println(Thread.currentThread().getName());
    }
}

class MyThread extends Thread {
    @Override
    public void run() {
        System.out.println(Thread.currentThread().getName());
    }
}

2. 实现Runnable接口

public class ThreadDemo {
    public static void main(String[] args) {
        MyThread myThread = new MyThread();
        Thread t = new Thread(myThread);
        t.start();
        System.out.println(Thread.currentThread().getName());
    }
}

class MyThread implements Runnable {
    @Override
    public void run() {
        System.out.println(Thread.currentThread().getName());
    }
}

3. 使用Callable和Future创建线程

public class ThreadDemo {
    public static void main(String[] args) {
        MyCallable myCallable = new MyCallable();
        FutureTask<Integer> future = new FutureTask<>(myThread);
        Thread t = new Thread(future);
        t.start();
        System.out.println(Thread.currentThread().getName());
    }
}

class MyCallable implements Callable<Integer> {

    @Override
    public Integer call() throws Exception {
        System.out.println(Thread.currentThread().getName());
        return 0;
    }
}

4. 使用线程池创建线程

public class ThreadDemo {
    public static void main(String[] args) throws ExecutionException, InterruptedException {
        // 创建一个具有固定大小的线程池
        ExecutorService executorService = Executors.newFixedThreadPool(3);
        // 创建一个任务
        Callable<Integer> callable = new MyCallable();
        // 提交任务
        Future future = executorService.submit(callable);
        // 获取任务执行结果 此方法会阻塞
        System.out.println(future.get());
        // 关闭线程池
        executorService.shutdown();
    }
}

class MyCallable implements Callable<Integer> {

    @Override
    public Integer call() throws Exception {
        System.out.println(Thread.currentThread().getName());
        return 0;
    }
}