Minimal ExoPlayer

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.startingtemplate.MainActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!" />

    <com.google.android.exoplayer2.ui.SimpleExoPlayerView
        android:id="@+id/a_main_exoplayer"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

    </com.google.android.exoplayer2.ui.SimpleExoPlayerView>

</LinearLayout>

AndroidManifest.xml

<uses-permission android:name="android.permission.INTERNET" />

build.gradle

dependencies {
    // ...
    compile 'com.google.android.exoplayer:exoplayer:r2.2.0'
}

MainActivity.java

public class MainActivity extends AppCompatActivity {


    private static final String VIDEO_URI = "http://techslides.com/demos/sample-videos/small.mp4";

    private SimpleExoPlayer player;
    private SimpleExoPlayerView simpleExoPlayerView;
    private static final DefaultBandwidthMeter bandwidthMeter = new DefaultBandwidthMeter();

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

        simpleExoPlayerView = (SimpleExoPlayerView) findViewById(R.id.a_main_exoplayer);

        createPlayer();
        attachPlayerView();
        preparePlayer();
    }

    public void createPlayer() {
        TrackSelection.Factory videoTrackSelectionFactory
                = new AdaptiveVideoTrackSelection.Factory(bandwidthMeter);
        player = ExoPlayerFactory.newSimpleInstance(this,
                new DefaultTrackSelector(videoTrackSelectionFactory), new DefaultLoadControl());
    }

    public void attachPlayerView() {
        simpleExoPlayerView.setPlayer(player);
    }

    public void preparePlayer() {
        DataSource.Factory dataSourceFactory = new DefaultDataSourceFactory(this, bandwidthMeter,
                buildHttpDataSourceFactory(bandwidthMeter));
        MediaSource videoSource = new ExtractorMediaSource(Uri.parse(VIDEO_URI),
                dataSourceFactory, new DefaultExtractorsFactory(), new Handler(), null);
        player.prepare(videoSource);
    }

    private HttpDataSource.Factory buildHttpDataSourceFactory(DefaultBandwidthMeter bandwidthMeter) {
        return new DefaultHttpDataSourceFactory(Util.getUserAgent(this,
                getString(R.string.app_name)), bandwidthMeter);
    }
}