1、实现Callable接口

class MyThread implements Callable{
    @Override
    public Integer call() throws Exception {
        System.out.println("callable");
        return 0;
    }
}

2、实现runnable接口

class MyThread2 implements Runnable{
    @Override
    public void run() {
        System.out.println("runnable");
    }
}

3、继承Thread

class MyThread3 extends  Thread{
    @Override
    public void run() {
        System.out.println("thread");
    }
}

runnable与callable的差异
1、实现方法不同
2、是否抛异常
3、有无返回值

启动线程的方式

public static void main(String[] args) throws Exception {
        //实现runnable接口
        new Thread(new MyThread2()).start();
        //继承Thread
        new MyThread3().start();
        //实现callable
        FutureTask<Integer> futureTask = new FutureTask(new MyThread());
        new Thread(futureTask,"A").start();
        Integer o = futureTask.get();
        System.err.println((Integer)o);
    }