android做一个循环执行的线程

final Handler handler=new Handler();  
final Runnable runnable=new Runnable() {  
    @Override  
    public void run() {  
        // TODO Auto-generated method stub  
    //要做的事情  
       handler.postDelayed(this, 1000);  // 1秒后执行
    }  
};  
handler.postDelayed(runnable, 1000);//1秒执行一次runnable.