Java 并发编程中如何创建线程

public class MyThread extends Thread {
 /**
  * 线程要执行的任务
  */
 @Override
 public void run() {
  System.out.println("do something...");
 }

 public static void main(String[] args) {	
	//创建线程
  MyThread myThread = new MyThread();
	//启动线程
  myThread.start();	
 }
}

public class MyThread implements Runnable {
  /**
  * 线程要执行的任务
  */
 @Override
 public void run() {
  System.out.println("do something...");
 }

 public static void main(String[] args) {
	//创建两个线程，并指定相同的任务
	Thread thread1 = new Thread(new MyThread());
  Thread thread2 = new Thread(new MyThread());
	//启动线程
  thread1.start();
  thread2.start();
 }
}

public class MyThread implements Callable<String> {
 /**
  * 线程要执行的任务，并且具有返回值
  */
 @Override
 public String call() throws Exception {
  System.out.println("do something...");
  Thread.sleep(3000);
  return "我是返回值";
 }

 public static void main(String[] args) throws ExecutionException, InterruptedException {
	//创建异步任务
  FutureTask<String> futureTask = new FutureTask(new MyThread());
	//启动线程
  new Thread(futureTask).start();
	//阻塞等待线程执行完成并返回结果
  String result = futureTask.get();
  System.out.println(result);
 }
}