类Thread

public class ThreadDemo extends Thread {    public static void main(String[] args) {        ThreadDemo thread = new ThreadDemo();        thread.start();    }    @Override    public void run() {        System.out.println("这是Thread方式启动的");    }}

运行结果如下：

接口Runnable

public class RunnableDemo implements Runnable {    @Override    public void run() {        System.out.println("这是Runnable方式启动的");    }    public static void main(String[] args) {        Thread thread = new Thread(new RunnableDemo());        thread.start();    }}

运行结果如下：

接口Callable

public class CallableDemo implements Callable {    @Override    public String call() throws Exception {        return "Callable";    }    public static void main(String[] args) {        FutureTask<String> futureTask = new FutureTask(new CallableDemo());        Thread thread = new Thread(futureTask);        thread.start();        try {            System.out.println(futureTask.get());        } catch (InterruptedException e) {            e.printStackTrace();        } catch (ExecutionException e) {            e.printStackTrace();        }    }}

运行结果如下：

接口Runnable和接口Callable的区别

1. Callable可以有返回值。
2. 通过FutureTask包装成Runnable，传递给Thread，因为FutureTask是实现了Runnable接口。