《java编程思想》--多线程基础--Runnable

一、简单说下Runnable是什么

1、它是一个接口

2、只提供了run方法

3、这个接口提供了一个协议：实现这个接口的类是active的（不必成为Thread的子类）

4、run方法没有返回值

 /**
  * The <code>Runnable</code> interface should be implemented by any
  * class whose instances are intended to be executed by a thread. The
  * class must define a method of no arguments called <code>run</code>.
  * <p>
  * This interface is designed to provide a common protocol for objects that
  * wish to execute code while they are active. For example,
  * <code>Runnable</code> is implemented by class <code>Thread</code>.
  * Being active simply means that a thread has been started and has not
  * yet been stopped.
  * <p>
  * In addition, <code>Runnable</code> provides the means for a class to be
  * active while not subclassing <code>Thread</code>. A class that implements
  * <code>Runnable</code> can run without subclassing <code>Thread</code>
  * by instantiating a <code>Thread</code> instance and passing itself in
  * as the target.  In most cases, the <code>Runnable</code> interface should
  * be used if you are only planning to override the <code>run()</code>
  * method and no other <code>Thread</code> methods.
  * This is important because classes should not be subclassed
  * unless the programmer intends on modifying or enhancing the fundamental
  * behavior of the class.
  *
  * @author  Arthur van Hoff
  * @see     java.lang.Thread
  * @see     java.util.concurrent.Callable
  * @since   JDK1.0
  */
 @FunctionalInterface
 public interface Runnable {
     /**
      * When an object implementing interface <code>Runnable</code> is used
      * to create a thread, starting the thread causes the object's
      * <code>run</code> method to be called in that separately executing
      * thread.
      * <p>
      * The general contract of the method <code>run</code> is that it may
      * take any action whatsoever.
      *
      * @see     java.lang.Thread#run()
      */
     public abstract void run();
 }

Runnable源码

　二、简单总结下如何使用

具体见《java编程思想》p654

定义一个类LiftOff实现这个接口，如：

public class LiftOff implements Runnable ...(省略)
Thread t = new Thread(new LiftOff());
t.start();