ExoPlayer2 - 如何使HTTP 301重定向工作？

Question

我开始使用ExoPlayer来传输一些音频.一切顺利,直到我遇到一个"301 Moved Permanently"重定向的URL.默认情况下,ExoPlayer2不处理该问题.

我已经看过这个帖子:https://github.com/google/ExoPlayer/issues/423

他们说在那里将新的"allowCrossDomainRedirects"标志添加到HttpDataSource或UriDataSource.问题是我不使用这些类中的任何一个:

//I am NOT using SimpleExoPlayer because I need a different renderer.
exoPlayer = ExoPlayerFactory.newInstance(renderers, trackSelector, loadControl);

final DataSource.Factory dataSourceFactory = new DefaultDataSourceFactory(
            context,
            Util.getUserAgent(context, applicationInfo.getAppName())
);

// Produces Extractor instances for parsing the media data.
final ExtractorsFactory extractorsFactory = new DefaultExtractorsFactory();

// This is the MediaSource representing the media to be played.
MediaSource mediaSource = new ExtractorMediaSource(
            Uri.parse(media.getUriString()) /* uri */,
            dataSourceFactory,
            extractorsFactory,
            10,
            null /* eventHandler */,
            null /* eventListener */);

exoPlayer.prepare(mediaSource);

了解ExtractorMediaSource如何需要dataSourceFactory而不是DataSource.实际上我甚至无法在ExoPlayer2上找到类HttpDataSource和UriDataSource.看起来他们已被删除.

因此我找不到添加帖子中提到的标志的方法.有人能帮助我吗？

Answer 1

该问题中描述的问题是关于跨协议重定向(从http到https,反之亦然).Exoplayer支持此功能,但您必须设置allowCrossProtocolRedirects为true.默认情况下支持常规重定向(包括301重定向).您接收的重定向很可能是跨协议重定向.

要创建您正在调用的数据源:

DefaultDataSourceFactory(Context context, String userAgent)

此构造函数创建一个DefaultHttpDataSourceFactory已allowCrossProtocolRedirects设置为false.

要更改此设置,您需要致电:

DefaultDataSourceFactory(Context context, TransferListener<? super DataSource> listener,
  DataSource.Factory baseDataSourceFactory)

并使用你自己DefaultHttpDataSourceFactory的allowCrossProtocolRedirects设置true为baseDataSourceFactory.

例如:

String userAgent = Util.getUserAgent(context, applicationInfo.getAppName());

// Default parameters, except allowCrossProtocolRedirects is true
DefaultHttpDataSourceFactory httpDataSourceFactory = new DefaultHttpDataSourceFactory(
    userAgent,
    null /* listener */,
    DefaultHttpDataSource.DEFAULT_CONNECT_TIMEOUT_MILLIS,
    DefaultHttpDataSource.DEFAULT_READ_TIMEOUT_MILLIS,
    true /* allowCrossProtocolRedirects */
);

DefaultDataSourceFactory dataSourceFactory = new DefaultDataSourceFactory(
    context,
    null /* listener */,
    httpDataSourceFactory
);

如果您需要更频繁地执行此操作,还可以创建辅助方法:

public static DefaultDataSourceFactory createDataSourceFactory(Context context,
        String userAgent, TransferListener<? super DataSource> listener) {
    // Default parameters, except allowCrossProtocolRedirects is true
    DefaultHttpDataSourceFactory httpDataSourceFactory = new DefaultHttpDataSourceFactory(
        userAgent,
        listener,
        DefaultHttpDataSource.DEFAULT_CONNECT_TIMEOUT_MILLIS,
        DefaultHttpDataSource.DEFAULT_READ_TIMEOUT_MILLIS,
        true /* allowCrossProtocolRedirects */
    );

    DefaultDataSourceFactory dataSourceFactory = new DefaultDataSourceFactory(
        context,
        listener,
        httpDataSourceFactory
    );

    return dataSourceFactory;
}

这将允许跨协议重定向.

旁注:"301 Moved Permanently"表示客户需要将其URL更新为新URL."302 Found"用于常规重定向.如果可能,请更新返回"301 Moved Permanently"的URL.