import com.google.android.exoplayer2.upstream.FileDataSource; //导入依赖的package包/类
/**
 * Returns a new {@link CacheDataSource} instance. If {@code offline} is true, it can only read
 * data from the cache.
 */
public CacheDataSource buildCacheDataSource(boolean offline) {
  DataSource cacheReadDataSource = cacheReadDataSourceFactory != null
      ? cacheReadDataSourceFactory.createDataSource() : new FileDataSource();
  if (offline) {
    return new CacheDataSource(cache, DummyDataSource.INSTANCE,
        cacheReadDataSource, null, CacheDataSource.FLAG_BLOCK_ON_CACHE, null);
  } else {
    DataSink cacheWriteDataSink = cacheWriteDataSinkFactory != null
        ? cacheWriteDataSinkFactory.createDataSink()
        : new CacheDataSink(cache, CacheDataSource.DEFAULT_MAX_CACHE_FILE_SIZE);
    DataSource upstream = upstreamDataSourceFactory.createDataSource();
    upstream = priorityTaskManager == null ? upstream
        : new PriorityDataSource(upstream, priorityTaskManager, C.PRIORITY_DOWNLOAD);
    return new CacheDataSource(cache, upstream, cacheReadDataSource,
        cacheWriteDataSink, CacheDataSource.FLAG_BLOCK_ON_CACHE, null);
  }
}
 

import com.google.android.exoplayer2.upstream.FileDataSource; //导入依赖的package包/类
private static CacheDataSource buildCacheDataSource(Context context, DataSource upstreamSource,
    boolean useAesEncryption) throws CacheException {
  File cacheDir = context.getExternalCacheDir();
  Cache cache = new SimpleCache(new File(cacheDir, EXO_CACHE_DIR), new NoOpCacheEvictor());
  emptyCache(cache);

  // Source and cipher
  final String secretKey = "testKey:12345678";
  DataSource file = new FileDataSource();
  DataSource cacheReadDataSource = useAesEncryption
      ? new AesCipherDataSource(Util.getUtf8Bytes(secretKey), file) : file;

  // Sink and cipher
  CacheDataSink cacheSink = new CacheDataSink(cache, EXO_CACHE_MAX_FILESIZE);
  byte[] scratch = new byte[3897];
  DataSink cacheWriteDataSink = useAesEncryption
      ? new AesCipherDataSink(Util.getUtf8Bytes(secretKey), cacheSink, scratch) : cacheSink;

  return new CacheDataSource(cache,
      upstreamSource,
      cacheReadDataSource,
      cacheWriteDataSink,
      CacheDataSource.FLAG_BLOCK_ON_CACHE,
      null); // eventListener
}
 

import com.google.android.exoplayer2.upstream.FileDataSource; //导入依赖的package包/类
private CacheDataSource createCacheDataSource(boolean setReadException,
    boolean simulateUnknownLength, @CacheDataSource.Flags int flags,
    CacheDataSink cacheWriteDataSink) {
  FakeDataSource upstream = new FakeDataSource();
  FakeData fakeData = upstream.getDataSet().newDefaultData()
      .setSimulateUnknownLength(simulateUnknownLength).appendReadData(TEST_DATA);
  if (setReadException) {
    fakeData.appendReadError(new IOException("Shouldn't read from upstream"));
  }
  return new CacheDataSource(cache, upstream, new FileDataSource(), cacheWriteDataSink,
      flags, null);
}
 

import com.google.android.exoplayer2.upstream.FileDataSource; //导入依赖的package包/类
@Override
public DataSource createDataSource() {
    LeastRecentlyUsedCacheEvictor evictor = new LeastRecentlyUsedCacheEvictor(maxCacheSize);
    SimpleCache simpleCache =
            new SimpleCache(new File(context.getCacheDir(), "media"), evictor);
    return new CacheDataSource(simpleCache, defaultDatasourceFactory.createDataSource(),
            new FileDataSource(), new CacheDataSink(simpleCache, maxFileSize),
            CacheDataSource.FLAG_BLOCK_ON_CACHE | CacheDataSource.FLAG_IGNORE_CACHE_ON_ERROR,
            null);
}
 

import com.google.android.exoplayer2.upstream.FileDataSource; //导入依赖的package包/类
@Override
public DataSource createDataSource() {
    return new CacheDataSource(simpleCache, defaultDatasourceFactory.createDataSource(),
            new FileDataSource(), new CacheDataSink(simpleCache, CacheDataSource.DEFAULT_MAX_CACHE_FILE_SIZE),
            0, listener);
}
 

import com.google.android.exoplayer2.upstream.FileDataSource; //导入依赖的package包/类
private void initPlayer(String url) {
        // 1.创建一个默认TrackSelector,测量播放过程中的带宽。 如果不需要，可以为null。
        DefaultBandwidthMeter bandwidthMeter = new DefaultBandwidthMeter();
        //从MediaSource中选出media提供给可用的Render S来渲染,在创建播放器时被注入
        TrackSelection.Factory videoTrackSelectionFactory =
                new AdaptiveTrackSelection.Factory(bandwidthMeter);
        TrackSelector trackSelector =
                new DefaultTrackSelector(videoTrackSelectionFactory);
        // 2.创建一个默认的LoadControl
        //Create a default LoadControl 控制MediaSource缓存media
        DefaultLoadControl loadControl = new DefaultLoadControl();
//        BufferingLoadControl bufferingLoadControl = new BufferingLoadControl();
        //生成加载媒体数据的DataSource实例。
//        dataSourceFactory = new DefaultDataSourceFactory(this,
//                Util.getUserAgent(this, "aitrip"), bandwidthMeter);
        //自定义解密工厂
        aitripFactory = new AitripDataSourceFactory(this,
                Util.getUserAgent(this, "aitrip"), bandwidthMeter);
        extractorsFactory = new DefaultExtractorsFactory();
//        factory = new DiyExtractorsFactory();
        FileDataSource fileDataSource = new FileDataSource();
        //test mp3
//        url = "https://storage.googleapis.com/exoplayer-test-media-0/play.mp3";
        // MediaSource代表要播放的媒体。
        videoSource = new ExtractorMediaSource(Uri.parse(url),
                aitripFactory, extractorsFactory, null, null);
        // 3.创建播放器
        player = ExoPlayerFactory.newSimpleInstance(this, trackSelector, loadControl);

        //SimpleExoPlayerView simpleExoPlayerView = (SimpleExoPlayerView) findViewById(R.id.exo_player);
        //设置监听器
        player.addListener(eventListener);
        //装载多个资源
        MediaSource[] mediaSources = new MediaSource[1];
//        mediaSources[0] = buildMediaSource(Uri.parse(huai), "");
//        mediaSources[1] = buildMediaSource(Uri.parse(deng), "");
        mediaSources[0] = buildMediaSource(Uri.parse(deng), "");
//        mediaSources[2] = buildMediaSource(playerUri, "");
//        mediaSources[3] = buildMediaSource(Uri.parse(deng), "");
        ConcatenatingMediaSource mediaSource = new ConcatenatingMediaSource(mediaSources);

        //设置资源
        player.prepare(mediaSource);
        window = new Timeline.Window();
    }
 

import com.google.android.exoplayer2.upstream.FileDataSource; //导入依赖的package包/类
/**
 * Constructs an instance with default {@link DataSource} and {@link DataSink} instances for
 * reading and writing the cache. The sink is configured to fragment data such that no single
 * cache file is greater than maxCacheFileSize bytes.
 *
 * @param cache The cache.
 * @param upstream A {@link DataSource} for reading data not in the cache.
 * @param flags A combination of {@link #FLAG_BLOCK_ON_CACHE}, {@link #FLAG_IGNORE_CACHE_ON_ERROR}
 *     and {@link #FLAG_IGNORE_CACHE_FOR_UNSET_LENGTH_REQUESTS}, or 0.
 * @param maxCacheFileSize The maximum size of a cache file, in bytes. If the cached data size
 *     exceeds this value, then the data will be fragmented into multiple cache files. The
 *     finer-grained this is the finer-grained the eviction policy can be.
 */
public CacheDataSource(Cache cache, DataSource upstream, @Flags int flags,
    long maxCacheFileSize) {
  this(cache, upstream, new FileDataSource(), new CacheDataSink(cache, maxCacheFileSize),
      flags, null);
}
 

import com.google.android.exoplayer2.upstream.FileDataSource; //导入依赖的package包/类
/**
 * Constructs an instance with default {@link DataSource} and {@link DataSink} instances for
 * reading and writing the cache. The sink is configured to fragment data such that no single
 * cache file is greater than maxCacheFileSize bytes.
 *
 * @param cache The cache.
 * @param upstream A {@link DataSource} for reading data not in the cache.
 * @param flags A combination of {@link #FLAG_BLOCK_ON_CACHE} and {@link
 *     #FLAG_IGNORE_CACHE_ON_ERROR} or 0.
 * @param maxCacheFileSize The maximum size of a cache file, in bytes. If the cached data size
 *     exceeds this value, then the data will be fragmented into multiple cache files. The
 *     finer-grained this is the finer-grained the eviction policy can be.
 */
public CacheDataSource(Cache cache, DataSource upstream, @Flags int flags,
    long maxCacheFileSize) {
  this(cache, upstream, new FileDataSource(), new CacheDataSink(cache, maxCacheFileSize),
      flags, null);
}
 

import com.google.android.exoplayer2.upstream.FileDataSource; //导入依赖的package包/类
/**
 * Constructs an instance with default {@link DataSource} and {@link DataSink} instances for
 * reading and writing the cache. The sink is configured to fragment data such that no single
 * cache file is greater than maxCacheFileSize bytes.
 *
 * @param cache The cache.
 * @param upstream A {@link DataSource} for reading data not in the cache.
 * @param flags A combination of {@link #FLAG_BLOCK_ON_CACHE}, {@link #FLAG_IGNORE_CACHE_ON_ERROR}
 *     and {@link #FLAG_CACHE_UNBOUNDED_REQUESTS} or 0.
 * @param maxCacheFileSize The maximum size of a cache file, in bytes. If the cached data size
 *     exceeds this value, then the data will be fragmented into multiple cache files. The
 *     finer-grained this is the finer-grained the eviction policy can be.
 */
public CacheDataSource(Cache cache, DataSource upstream, @Flags int flags,
    long maxCacheFileSize) {
  this(cache, upstream, new FileDataSource(), new CacheDataSink(cache, maxCacheFileSize),
      flags, null);
}