Android 如果exoplayer中的第一个媒体源出错，是否可以播放第二个媒体源？

我是初学者。有谁能帮我简要介绍一下这个问题吗。我得到两个链接动态

网址

交替

如果第一个媒体（url）出现错误，我想播放第二个媒体（备用）源。 我正在寻找这一个星期，一个好的答案将不胜感激。如果你不能解决问题，请把它投给更多的人。。提前谢谢

这是我的全部代码

ImageButton playPause,lockScreen,unLock;
SeekBar seekBar;
TextView start,end;
boolean isPlaying = false;
boolean isLock = false;
RelativeLayout controller;
FrameLayout root;

boolean isControllerShowing = true;
private Handler mHandler;


SimpleExoPlayerView simpleExoPlayerView;
private SimpleExoPlayer player;

SessionManagement management;
String url, alternate;
Uri mp4VideoUri;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_live_tv);

    checkConnection();


    Sensey.getInstance().init(this);

    Sensey.getInstance().startOrientationDetection(15,this);

    management = new SessionManagement(this);

    HashMap<String,String> hashMap = management.getUserDetails();

    url = hashMap.get(SessionManagement.LIVE_URL);
    alternate = hashMap.get(SessionManagement.ALTERNATE_URL);


    playPause = findViewById(R.id.btnPlayPause);
    lockScreen = findViewById(R.id.btnLock);
    unLock = findViewById(R.id.btnOpenLock);

    seekBar = findViewById(R.id.seeker);

    end = findViewById(R.id.duration);
    start = findViewById(R.id.position);

    controller = findViewById(R.id.layout_controller);
    root = findViewById(R.id.activity_live);

    try {
        BandwidthMeter bandwidthMeter = new DefaultBandwidthMeter();
        TrackSelection.Factory videoTrackSelectionFactory = new AdaptiveTrackSelection.Factory(bandwidthMeter);
        TrackSelector trackSelector = new DefaultTrackSelector(videoTrackSelectionFactory);

        LoadControl loadControl = new DefaultLoadControl();

        player = ExoPlayerFactory.newSimpleInstance(this, trackSelector, loadControl);
        simpleExoPlayerView = findViewById(R.id.video_view);

        simpleExoPlayerView.setUseController(false);
        simpleExoPlayerView.requestFocus();

        simpleExoPlayerView.setPlayer(player);


            mp4VideoUri = Uri.parse(url); //Radnom 540p indian channel



        mHandler = new Handler();


        DefaultBandwidthMeter bandwidthMeterA = new DefaultBandwidthMeter();
        DefaultDataSourceFactory dataSourceFactory = new 
        DefaultDataSourceFactory(this, Util.getUserAgent(this, "Madha TV"), bandwidthMeterA);

        DefaultExtractorsFactory();

        dataSourceFactory, extractorsFactory, null, null);

        MediaSource videoSource = new HlsMediaSource(mp4VideoUri, dataSourceFactory, 1, null, null);
        final LoopingMediaSource loopingSource = new LoopingMediaSource(videoSource);
        player.prepare(loopingSource);

        player.addListener(new ExoPlayer.EventListener() {

            @Override
            public void onTimelineChanged(Timeline timeline, Object manifest, int reason) {

            }

            @Override
            public void onTracksChanged(TrackGroupArray trackGroups, TrackSelectionArray trackSelections) {
            }

            @Override
            public void onLoadingChanged(boolean isLoading) {
            }

            @Override
            public void onPlayerStateChanged(boolean playWhenReady, int playbackState) {

            }

            @Override
            public void onRepeatModeChanged(int repeatMode) {
            }

            @Override
            public void onShuffleModeEnabledChanged(boolean shuffleModeEnabled) {

            }

            @Override
            public void onPlayerError(ExoPlaybackException error) {
                switch (error.type) {
                    case ExoPlaybackException.TYPE_SOURCE:
                        Log.e("Error", "TYPE_SOURCE: " + error.getSourceException().getMessage());
                        Intent intent1 = new Intent(LiveTVActivity.this, MainActivity.class);
                        startActivity(intent1);
                        finish();
                        Toast.makeText(LiveTVActivity.this, error.getSourceException().getMessage(), Toast.LENGTH_SHORT).show();
                        break;

                    case ExoPlaybackException.TYPE_RENDERER:
                        break;

                    case ExoPlaybackException.TYPE_UNEXPECTED:
                        Log.e("Error", "TYPE_UNEXPECTED: " + error.getUnexpectedException().getMessage());
                        break;
                }

                player.stop();
                player.prepare(loopingSource);
                player.setPlayWhenReady(true);

            }

            @Override
            public void onPositionDiscontinuity(int reason) {

            }

            @Override
            public void onPlaybackParametersChanged(PlaybackParameters playbackParameters) {
            }

            @Override
            public void onSeekProcessed() {

            }
        });

        player.setPlayWhenReady(true); //run file/link when ready to play.
        player.setVideoDebugListener(this); //for listening to resolution change and  outputing the resolution

        if (player.getPlayWhenReady())
        {
            playPause.setImageResource(R.drawable.cvp_action_pause);
            isPlaying = true;
        }
        else
        {
            playPause.setImageResource(R.drawable.cvp_action_play);
            isPlaying = false;
        }


        root.setOnClickListener(this);
        playPause.setOnClickListener(this);
        lockScreen.setOnClickListener(this);
        unLock.setOnClickListener(this);
    }
    catch (Exception e)
    {

        Log.e("Error",e.toString());
    }

}

@Override
public void onConfigurationChanged(Configuration newConfig) {
    super.onConfigurationChanged(newConfig);

    if (newConfig.orientation == Configuration.ORIENTATION_LANDSCAPE) {
        getWindow().clearFlags(WindowManager.LayoutParams.FLAG_FORCE_NOT_FULLSCREEN);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                WindowManager.LayoutParams.FLAG_FULLSCREEN);
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
            getWindow().getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_LOW_PROFILE);
        }
        updateMetadata();

    } else {
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FORCE_NOT_FULLSCREEN,
                WindowManager.LayoutParams.FLAG_FORCE_NOT_FULLSCREEN);
        getWindow().clearFlags(
                WindowManager.LayoutParams.FLAG_FULLSCREEN);
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
            getWindow().getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_VISIBLE);
        }
        updateMetadata();
    }

}


@Override
public void onTopSideUp() {
    updateMetadata();
    setRequestedOrientation (ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
}

@Override
public void onBottomSideUp() {

}

@Override
public void onRightSideUp() {
    updateMetadata();
    setRequestedOrientation (ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
}

@Override
public void onLeftSideUp() {
    updateMetadata();
    setRequestedOrientation (ActivityInfo.SCREEN_ORIENTATION_REVERSE_LANDSCAPE);
}

@SuppressWarnings("ConstantConditions")
private void updateMetadata() {
    Point displaySize;
    displaySize = Utils.getDisplaySize(this);

    FrameLayout.LayoutParams lp = new FrameLayout.LayoutParams(displaySize.x,displaySize.y);
    lp.gravity = Gravity.CENTER;
    simpleExoPlayerView.setLayoutParams(lp);
    simpleExoPlayerView.invalidate();

}
private void checkConnection()
{
    boolean isConnected = ConnectivityReceiver.isConnected();
    showSnack(isConnected);
}

// Showing the status in Snackbar
private void showSnack(boolean isConnected) {

    if (!isConnected) {
        Config.noConnection(LiveTVActivity.this);
    }
}


@Override
public void onClick(View view) {

    if (view.getId() == R.id.btnPlayPause) {
        setPlayPause();
    }else if (view.getId() == R.id.btnLock) {
        if (!isLock)
        {
            unLock.setVisibility(View.VISIBLE);
            isLock = true;
            controller.setVisibility(View.GONE);
            root.setClickable(false);
        }
    }else if (view.getId() == R.id.btnOpenLock)
    {
        if (isLock)
        {
            root.setClickable(true);
            isLock = false;
            unLock.setVisibility(View.GONE);
            controller.setVisibility(View.VISIBLE);
        }
    } else if (view.getId() == R.id.activity_live)
    {
        showController();
    }
}

public void showController()
{
    if (!isControllerShowing)
    {
        isControllerShowing = true;
        controller.setVisibility(View.VISIBLE);
    }
    else
    {
        isControllerShowing = false;
        controller.setVisibility(View.GONE);
    }
}

private void setPlayPause() {

    if (isPlaying)
    {
        player.setPlayWhenReady(false);
        isPlaying = false;
        playPause.setImageResource(R.drawable.cvp_action_play);
    }
    else
    {
        player.setPlayWhenReady(true);
        isPlaying = true;
        playPause.setImageResource(R.drawable.cvp_action_pause);
    }

}

@Override
public void onNetworkConnectionChanged(boolean isConnected) {
    showSnack(isConnected);
}

@Override
public void onVideoEnabled(DecoderCounters counters) {

}

@Override
public void onVideoDecoderInitialized(String decoderName, long initializedTimestampMs, long initializationDurationMs) {

}

@Override
public void onVideoInputFormatChanged(Format format) {

}

@Override
public void onDroppedFrames(int count, long elapsedMs) {

}

@Override
public void onVideoSizeChanged(int width, int height, int unappliedRotationDegrees, float pixelWidthHeightRatio) {
}

@Override
public void onRenderedFirstFrame(Surface surface) {

}

@Override
public void onVideoDisabled(DecoderCounters counters) {

}

ImageButton播放暂停、锁屏、解锁；
SeekBar-SeekBar；
文本视图开始，结束；
布尔isplay=false；
布尔值isLock=false；
相对延迟控制器；
框架布局根；
布尔值iscontrollershow=true；
私人经理人；
SimpleXoplayerView SimpleXoplayerView；
私人SimpleExoPlayer；
会话管理；
字符串url，可选；
urimp4videouri；
@凌驾
创建时受保护的void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.activity\u live\u tv）；
检查连接（）；
Sensey.getInstance（）.init（this）；
Sensey.getInstance（）；
管理=新的会话管理（本）；
HashMap HashMap=management.getUserDetails（）；
url=hashMap.get（SessionManagement.LIVE_url）；
alternate=hashMap.get（SessionManagement.alternate_URL）；
playPause=findviewbyd（R.id.btnPlayPause）；
锁屏=findViewById（R.id.btnLock）；
解锁=findViewById（R.id.btnOpenLock）；
seekBar=findViewById（R.id.seeker）；
结束=findViewById（R.id.持续时间）；
开始=findViewById（R.id.position）；
控制器=findViewById（R.id.layout\U控制器）；
root=findviewbyd（R.id.activity\u live）；
试一试{
带宽计带宽计=新的默认带宽计（）；
TrackSelection.Factory videoTrackSelectionFactory=新的AdaptiveTrackSelection.Factory（带宽计）；
TrackSelector TrackSelector=新的默认TrackSelector（videoTrackSelectionFactory）；
LoadControl LoadControl=新的DefaultLoadControl（）；
player=ExoPlayerFactory.newImpleInstance（此、轨迹选择器、加载控件）；
simpleExoPlayerView=findviewbyd（R.id.video\u视图）；
simpleExoPlayerView.setUseController（false）；
SimpleXoPlayerView.requestFocus（）；
simpleExoPlayerView.setPlayer（播放器）；
mp4VideoUri=Uri.parse（url）；//Radnom 540p印度频道
mHandler=新处理程序（）；
DefaultBandwidthMeterA=新的DefaultBandwidthMeter（）；
DefaultDataSourceFactory dataSourceFactory=新建
DefaultDataSourceFactory（这是Util.getUserAgent（这是“Madha TV”），bandwidthMeterA）；
DefaultExtractorFactory（）；
数据源工厂，提取器工厂，null，null）；
MediaSource videoSource=新的HlsMediaSource（mp4VideoUri，dataSourceFactory，1，null，null）；
最终LoopingMediaSource loopingSource=新的LoopingMediaSource（视频源）；
player.prepare（循环源）；
player.addListener（新的ExoPlayer.EventListener（）{
@凌驾
公共void onTimelineChanged（时间线、对象清单、整数原因）{
}
@凌驾
公共无效onTracksChanged（TrackGroupArray轨迹组、TrackSelectionArray轨迹选择）{
}
@凌驾
public void onload已更改（boolean isload）{
}
@凌驾
PlayerStateChanged上的公共无效（布尔playWhenReady，int playbackState）{
}
@凌驾
公共无效onRepeatModeChanged（int repeatMode）{
}
@凌驾
OnShuffleMemodeEnabledChanged（布尔ShuffleMemodeEnabled）上的公共无效{
}
@凌驾
public void onPlayerError（ExoPlaybackException错误）{
开关（错误类型）{
案例ExoPlaybackException.TYPE_来源：
Log.e（“Error”，“TYPE_SOURCE:”+Error.getSourceException（）.getMessage（））；
Intent intent1=新的Intent（LiveTVActivity.this、MainActivity.class）；
星触觉（intent1）；
完成（）；
Toast.makeText（LiveTVActivity.this，error.getSourceException（）.getMessage（），Toast.LENGTH_SHORT.show（）；
打破
case ExoPlaybackException.TYPE_渲染器：
打破
case ExoPlaybackException.TYPE_意外：
Log.e（“Error”，“TYPE_UNEXPECTED:”+Error.getUnexpectedException（）.getMessage（））；
打破
}
player.stop（）；
player.prepare（循环源）；
player.setplaywhenrady（true）；
}
@凌驾
公共位置不连续（内部原因）{
}
@凌驾
public void OnPlaybackParameters更改（PlaybackParameters PlaybackParameters）{
}
@凌驾
seekProcessed（）上的公共void{
}
});
player.setplaywhenredy（true）；//准备好播放时运行文件/链接。
player.setVideoDebugListener（this）；//用于侦听分辨率更改并输出分辨率
if（player.getplaywhenrady（））
{
playPause.setImageResource（R.drawable.cvp\u action\u pause）；
isplay=true；
}
其他的
{
playPause.setImageResource（R.drawable.cvp_action_play）；
isplay=false；
}
root.setOnClickListener（this）；
playPause.setOnClickListener（此）；
lockScreen.setOnClickListener（此）；
unLock.setOnClickListener（此）；
}
捕获（例外e）
{
Log.e（“Error”，e.toString（））；
}
}
@凌驾
公共无效OnConfiguration已更改（配置newConfig）{
超级配置已更改（新公司
public class VideoPlayerActivity extends AppCompatActivity implements ExoPlayer.EventListener {

private SimpleExoPlayer mSimpleExoPlayer;

private SimpleExoPlayerView mSimpleExoPlayerView;

private Handler mMainHandler;
private AdaptiveTrackSelection.Factory mAdaptiveTrackSelectionFactory;
private TrackSelector mTrackSelector;
private LoadControl mLoadControl;
private DefaultBandwidthMeter mBandwidthMeter;
private DataSource.Factory mDataSourceFactory;
private SimpleCache mSimpleCache;
private DataSource.Factory mFactory;
private MediaSource mVideoSource;
private LoopingMediaSource mLoopingMediaSource;
private ProgressBar mProgressBar;
private String videoUrl="http://sample.vodobox.net/skate_phantom_flex_4k/skate_phantom_flex_4k.m3u8";

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_video);
    mSimpleExoPlayerView = (SimpleExoPlayerView) findViewById(R.id.videoPlayer);
    mProgressBar = (ProgressBar) findViewById(R.id.amPrgbrLoading);
}

/**
 * this method play audio and video with hls streaming.
 */
private void playMedia() {
    mMainHandler = new Handler();
    mBandwidthMeter = new DefaultBandwidthMeter();
    mAdaptiveTrackSelectionFactory = new AdaptiveTrackSelection.Factory(mBandwidthMeter);
    mTrackSelector = new DefaultTrackSelector(mAdaptiveTrackSelectionFactory);

    mLoadControl = new DefaultLoadControl();
    mSimpleExoPlayer = ExoPlayerFactory.newSimpleInstance(this, mTrackSelector, mLoadControl);

    mSimpleExoPlayerView.setPlayer(mSimpleExoPlayer);
    mSimpleExoPlayerView.setControllerVisibilityListener(new PlaybackControlView.VisibilityListener() {
        @Override
        public void onVisibilityChange(int visibility) {
            mSimpleExoPlayerView.showController();
        }
    });
    mDataSourceFactory = new DefaultDataSourceFactory(this,Util.getUserAgent(this, "com.exoplayerdemo"), mBandwidthMeter);
    mSimpleCache = new SimpleCache(this.getCacheDir(), new LeastRecentlyUsedCacheEvictor(1024 * 1024 * 10));
    mFactory = new CacheDataSourceFactory(mSimpleCache, mDataSourceFactory,0);
    mVideoSource = new HlsMediaSource(Uri.parse(videoUrl),
            mFactory, mMainHandler, new AdaptiveMediaSourceEventListener() {
        @Override
        public void onLoadStarted(DataSpec dataSpec, int dataType, int trackType, Format trackFormat, int trackSelectionReason, Object trackSelectionData, long mediaStartTimeMs, long mediaEndTimeMs, long elapsedRealtimeMs) {
            //Toast.makeText(VideoPlayerActivity.this, "Load Started", Toast.LENGTH_SHORT).show();
        }

        @Override
        public void onLoadCompleted(DataSpec dataSpec, int dataType, int trackType, Format trackFormat, int trackSelectionReason, Object trackSelectionData, long mediaStartTimeMs, long mediaEndTimeMs, long elapsedRealtimeMs, long loadDurationMs, long bytesLoaded) {
            //Toast.makeText(VideoPlayerActivity.this, "Load Completed", Toast.LENGTH_SHORT).show();
        }

        @Override
        public void onLoadCanceled(DataSpec dataSpec, int dataType, int trackType, Format trackFormat, int trackSelectionReason, Object trackSelectionData, long mediaStartTimeMs, long mediaEndTimeMs, long elapsedRealtimeMs, long loadDurationMs, long bytesLoaded) {

        }

        @Override
        public void onLoadError(DataSpec dataSpec, int dataType, int trackType, Format trackFormat, int trackSelectionReason, Object trackSelectionData, long mediaStartTimeMs, long mediaEndTimeMs, long elapsedRealtimeMs, long loadDurationMs, long bytesLoaded, IOException error, boolean wasCanceled) {
            videoUrl=""; // define second url
        }

        @Override
        public void onUpstreamDiscarded(int trackType, long mediaStartTimeMs, long mediaEndTimeMs) {
           // Toast.makeText(VideoPlayerActivity.this, "Up stream", Toast.LENGTH_SHORT).show();
        }

        @Override
        public void onDownstreamFormatChanged(int trackType, Format trackFormat, int trackSelectionReason, Object trackSelectionData, long mediaTimeMs) {
           // Toast.makeText(VideoPlayerActivity.this, "Down Stream", Toast.LENGTH_SHORT).show();
        }
    });

    mLoopingMediaSource = new LoopingMediaSource(mVideoSource);
    mSimpleExoPlayer.prepare(mLoopingMediaSource);
    mSimpleExoPlayer.setPlayWhenReady(true);
    mSimpleExoPlayer.addListener(new ExoPlayer.EventListener() {
        @Override
        public void onTimelineChanged(Timeline timeline, Object manifest) {

        }

        @Override
        public void onTracksChanged(TrackGroupArray trackGroups, TrackSelectionArray trackSelections) {

        }

        @Override
        public void onLoadingChanged(boolean isLoading) {

        }

        @Override
        public void onPlayerStateChanged(boolean playWhenReady, int playbackState) {

            if (playbackState == ExoPlayer.STATE_BUFFERING) {
                mProgressBar.setVisibility(View.VISIBLE);
            } else {
                mProgressBar.setVisibility(View.GONE);
            }

        }

        @Override
        public void onPlayerError(ExoPlaybackException error) {

        }

        @Override
        public void onPositionDiscontinuity() {

        }
    });



}

@Override
protected void onResume() {
    super.onResume();
    playMedia();
}

@Override
protected void onStop() {
    super.onStop();
    stopMedia();
}

@Override
protected void onPause() {
    super.onPause();
    stopMedia();
}

private void stopMedia() {
    mSimpleExoPlayer.stop();
    mSimpleExoPlayer.release();
}



@Override
public void onTimelineChanged(Timeline timeline, Object manifest) {

}

@Override
public void onTracksChanged(TrackGroupArray trackGroups, TrackSelectionArray trackSelections) {

}

@Override
public void onLoadingChanged(boolean isLoading) {

}

@Override
public void onPlayerStateChanged(boolean playWhenReady, int playbackState) {

}

@Override
public void onPlayerError(ExoPlaybackException error) {

}

@Override
public void onPositionDiscontinuity() {

}
}

simpleExoPlayerView.requestFocus();
                TrackSelection.Factory videoTrackSelectionFactory =
                        new AdaptiveTrackSelection.Factory(BANDWIDTH_METER);
                trackSelector = new DefaultTrackSelector(videoTrackSelectionFactory);

            player = ExoPlayerFactory.newSimpleInstance(this, trackSelector);

            simpleExoPlayerView.setPlayer(player);
            //player.setPlayWhenReady(shouldAutoPlay);

            player.addListener(this);

            DefaultExtractorsFactory extractorsFactory = new DefaultExtractorsFactory();

            MediaSource mediaSource = new ExtractorMediaSource(videoUri,
                    mediaDataSourceFactory, extractorsFactory, null, null);
            player.prepare(mediaSource);
            if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N) {
                // Call some material design APIs here
                // player.setPlayWhenReady(true);
            }

            inErrorState = false;
        } catch (Exception e) {
            e.printStackTrace();
            Log.e("Please try again", "download again");
        }
    }

  private void errorinitializePlayer() {
  videoUri = Uri.parse(VIDEOS_URL);
                simpleExoPlayerView.requestFocus();
                TrackSelection.Factory videoTrackSelectionFactory =
                        new AdaptiveTrackSelection.Factory(BANDWIDTH_METER);

                trackSelector = new DefaultTrackSelector(videoTrackSelectionFactory);

                player = ExoPlayerFactory.newSimpleInstance(this, trackSelector);

                simpleExoPlayerView.setPlayer(player);
                //player.setPlayWhenReady(shouldAutoPlay);
                player.addListener(this);
                DefaultExtractorsFactory extractorsFactory = new DefaultExtractorsFactory();
                MediaSource mediaSource = new ExtractorMediaSource(videoUri,
                        mediaDataSourceFactory, extractorsFactory, null, null);
                player.prepare(mediaSource);
                inErrorState = false;}