public static final int ALL = 0;//全部循环
public static final int SINGLE = 1;//单曲循环
public static final int RANDOM = 2;//随机

// 一首歌播放完成后(这里设置播放模式)
public class Completed implements OnCompletionListener
{
       @Override
       public void onCompletion(MediaPlayer mp)
       {
             if(playMode == ALL)//全部循环
             {
                   if (position == listMusic.size() - 1)//默认循环播放
                   {
                         position = 0;// 第一首
                   }
                   else
                   {
                         position++;
                   }
             }
             else if(playMode == SINGLE)//单曲循环
             {
                   //position不需要更改
             }
             else if(playMode == RANDOM)//随机
             {
                   position = (int)(Math.random()*listMusic.size());//随机播放
             }
             elseSet();//其他播放的处理
       }
}