### 数据源工厂类
 ####  1.默认数据源
  >>        缓存 : CacheDataSinkFactory,CacheDataSourceFactory
  >>         http : DefaultDataSourceFactory,DefaultHttpDataSourceFactory
  >>         Priority : PriorityDataSourceFactory
#### 2 自定义数据源引用

  >>      compile 'com.google.android.exoplayer:extension-okhttp:2.8.4'
  >>       compile 'com.google.android.exoplayer:extension-rtmp:2.8.4'

>>#### 3.自定义数据源工厂类:
   * 实现接口 DataSourceListener  然后在getDataSourceFactory方法里 自定义 数据源
   * 在你使用播放控件时中实例化类

   >>       exoPlayerManager = new VideoPlayerManager.Builder(VideoPlayerManager.TYPE_PLAY_MANUAL, videoPlayerView)
   >>                                                                                     .setDataSource(mediaSourceBuilder)
   >>                                                                                     .create();

   * demo代码:
   ``````
        public class DataSource implements DataSourceListener {
             public static final String TAG = "DataSource";
              private Context context;
              public   DataSource (Context context){
                  this.context=context;
               }
              @Override
              public com.google.android.exoplayer2.upstream.DataSource.Factory getDataSourceFactory() {
                   OkHttpClient  okHttpClient = new OkHttpClient();
                  OkHttpDataSourceFactory OkHttpDataSourceFactory=    new OkHttpDataSourceFactory(okHttpClient, Util.getUserAgent(context, context.getApplicationContext().getPackageName()),new DefaultBandwidthMeter() );
                      //使用OkHttpClient 数据源工厂
                    //return  OkHttpDataSourceFactory; ;
                    //默认数据源工厂
                    // return new JDefaultDataSourceFactory(context);
                    // Rtmp数据源工厂 对 Rtmp 协议支持
                    // return  new RtmpDataSourceFactory();
                   //缓存使用和组合使用
                    LeastRecentlyUsedCacheEvictor evictor = new LeastRecentlyUsedCacheEvictor(1000000000);
                   SimpleCache   simpleCache = new SimpleCache(new File(context.getCacheDir(), "media"), evictor);
                   //缓存数据源使用，内部使用DefaultDataSourceFactory数据源工厂类
                   // return  new CacheDataSinkFactory(simpleCache,10000);
                   // 配合okHttp数据源工厂类
                   return  new CacheDataSourceFactory(simpleCache, OkHttpDataSourceFactory);
                   //使用配合默认数据源红工厂类
                  // return  new CacheDataSourceFactory(simpleCache, new JDefaultDataSourceFactory(context));
                   //使用提供缓存数据源工厂类
                  // return new CacheDataSourceFactory(context,1000,1000);
                 }
       }
   ``````