继承Thread类

public class MyThread extends Thread {

    static int count = 0;
    @Override
    public void run() {
        System.out.println(count++);
    }

    public static void main(String[] args) {
        MyThread myThread1 = new MyThread();
        MyThread myThread2 = new MyThread();

        myThread1.start();
        myThread2.start();
    }

}

实现runnable接口

public class MyRunnable implements Runnable{

    static int count = 0;

    public void run() {
        System.out.println(count++);
    }

    public static void main(String[] args) {

        MyRunnable myRunnable = new MyRunnable();

        Thread myRunnable1 = new Thread(myRunnable);
        Thread myRunnable2 = new Thread(myRunnable);

        myRunnable1.start();
        myRunnable2.start();
    }
    
}

实现callable接口

public class MyCallable implements Callable<String> {

     static int count;

    public String call() throws Exception {

        System.out.println("count:"+count++);

        return String.valueOf(count);
    }

    public static void main(String[] args) throws ExecutionException, InterruptedException {
        MyCallable myCallable = new MyCallable();

        FutureTask<String> stringFutureTask1 = new FutureTask<String>(myCallable);
        FutureTask<String> stringFutureTask2 = new FutureTask<String>(myCallable);

        Thread thread1 = new Thread(stringFutureTask1);
        Thread thread2 = new Thread(stringFutureTask2);

        thread1.start();

        System.out.println(stringFutureTask1.get());

        thread2.start();

        System.out.println(stringFutureTask2.get());

    }

}

线程池创建

public class MyExecutors implements Runnable{
    static int count = 0;

    public void run() {
        System.out.println(count++);
    }

    public static void main(String[] args) {
        ExecutorService pool = Executors.newFixedThreadPool(3);

        pool.submit(new MyExecutors());
        pool.submit(new MyExecutors());

        pool.shutdown();
    }

}