diff --git a/demos/main/src/main/java/com/google/android/exoplayer2/demo/DownloadActivity.java b/demos/main/src/main/java/com/google/android/exoplayer2/demo/DownloadActivity.java
index 3a088b530c..7e26ddbe56 100644
--- a/demos/main/src/main/java/com/google/android/exoplayer2/demo/DownloadActivity.java
+++ b/demos/main/src/main/java/com/google/android/exoplayer2/demo/DownloadActivity.java
@@ -20,15 +20,14 @@ import static com.google.android.exoplayer2.demo.PlayerActivity.EXTENSION_EXTRA;
 import android.app.Activity;
 import android.content.Intent;
 import android.net.Uri;
-import android.os.AsyncTask;
 import android.os.Bundle;
 import android.os.Parcelable;
-import android.util.SparseBooleanArray;
 import android.view.View;
 import android.widget.ArrayAdapter;
 import android.widget.ListView;
 import android.widget.Toast;
 import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.offline.DownloadAction;
 import com.google.android.exoplayer2.offline.DownloadService;
 import com.google.android.exoplayer2.offline.ProgressiveDownloadAction;
@@ -70,11 +69,9 @@ public class DownloadActivity extends Activity {
   private String sampleName;
 
   private TrackNameProvider trackNameProvider;
-  private AsyncTask manifestDownloaderTask;
-
-  private DownloadUtilMethods downloadUtilMethods;
+  private DownloadHelper<? extends Parcelable> downloadHelper;
   private ListView representationList;
-  private ArrayAdapter<RepresentationItem> arrayAdapter;
+  private ArrayAdapter<String> arrayAdapter;
 
   @Override
   protected void onCreate(Bundle savedInstanceState) {
@@ -100,37 +97,44 @@ public class DownloadActivity extends Activity {
     int type = Util.inferContentType(sampleUri, extension);
     switch (type) {
       case C.TYPE_DASH:
-        downloadUtilMethods = new DashDownloadUtilMethods(sampleUri, manifestDataSourceFactory);
+        downloadHelper = new DashDownloadHelper(sampleUri, manifestDataSourceFactory);
         break;
       case C.TYPE_SS:
-        downloadUtilMethods = new SsDownloadUtilMethods(sampleUri, manifestDataSourceFactory);
+        downloadHelper = new SsDownloadHelper(sampleUri, manifestDataSourceFactory);
         break;
       case C.TYPE_HLS:
-        downloadUtilMethods = new HlsDownloadUtilMethods(sampleUri, manifestDataSourceFactory);
+        downloadHelper = new HlsDownloadHelper(sampleUri, manifestDataSourceFactory);
         break;
       case C.TYPE_OTHER:
-        downloadUtilMethods = new ProgressiveDownloadUtilMethods(sampleUri);
+        downloadHelper = new ProgressiveDownloadHelper(sampleUri);
         break;
       default:
         throw new IllegalStateException("Unsupported type: " + type);
     }
 
-    updateRepresentationsList();
-  }
-
-  @Override
-  protected void onStart() {
-    super.onStart();
-    updateRepresentationsList();
-  }
-
-  @Override
-  protected void onStop() {
-    if (manifestDownloaderTask != null) {
-      manifestDownloaderTask.cancel(true);
-      manifestDownloaderTask = null;
-    }
-    super.onStop();
+    new Thread() {
+      @Override
+      public void run() {
+        try {
+          downloadHelper.init();
+          runOnUiThread(
+              new Runnable() {
+                @Override
+                public void run() {
+                  onInitialized();
+                }
+              });
+        } catch (IOException e) {
+          runOnUiThread(
+              new Runnable() {
+                @Override
+                public void run() {
+                  onInitializationError();
+                }
+              });
+        }
+      }
+    }.start();
   }
 
   // This method is referenced in the layout file
@@ -141,21 +145,31 @@ public class DownloadActivity extends Activity {
       startDownload();
     } else if (id == R.id.remove_all_button) {
       removeDownload();
-    } else if (id == R.id.refresh_button) {
-      updateRepresentationsList();
     } else if (id == R.id.play_button) {
       playDownload();
     }
   }
 
+  private void onInitialized() {
+    for (int i = 0; i < downloadHelper.getTrackCount(); i++) {
+      arrayAdapter.add(trackNameProvider.getTrackName(downloadHelper.getTrackFormat(i)));
+    }
+  }
+
+  private void onInitializationError() {
+    Toast.makeText(
+            getApplicationContext(), R.string.download_manifest_load_error, Toast.LENGTH_LONG)
+        .show();
+  }
+
   private void startDownload() {
-    ArrayList<Object> representationKeys = getSelectedRepresentationKeys();
-    if (!representationKeys.isEmpty()) {
+    int[] selectedTrackIndices = getSelectedTrackIndices();
+    if (selectedTrackIndices.length > 0) {
       DownloadService.addDownloadAction(
           this,
           DemoDownloadService.class,
-          downloadUtilMethods.getDownloadAction(
-              /* isRemoveAction= */ false, sampleName, representationKeys));
+          downloadHelper.getDownloadAction(
+              /* isRemoveAction= */ false, sampleName, selectedTrackIndices));
     }
   }
 
@@ -163,123 +177,87 @@ public class DownloadActivity extends Activity {
     DownloadService.addDownloadAction(
         this,
         DemoDownloadService.class,
-        downloadUtilMethods.getDownloadAction(
-            /* isRemoveAction= */ true, sampleName, Collections.emptyList()));
+        downloadHelper.getDownloadAction(/* isRemoveAction= */ true, sampleName));
     for (int i = 0; i < representationList.getChildCount(); i++) {
       representationList.setItemChecked(i, false);
     }
   }
 
-  @SuppressWarnings("SuspiciousToArrayCall")
   private void playDownload() {
-    ArrayList<Object> selectedRepresentationKeys = getSelectedRepresentationKeys();
-    if (selectedRepresentationKeys.isEmpty()) {
+    int[] selectedTrackIndices = getSelectedTrackIndices();
+    List<? extends Parcelable> keys = downloadHelper.getTrackKeys(selectedTrackIndices);
+    if (keys.isEmpty()) {
       playerIntent.removeExtra(PlayerActivity.MANIFEST_FILTER_EXTRA);
     } else {
-      Parcelable[] parcelables = new Parcelable[selectedRepresentationKeys.size()];
-      selectedRepresentationKeys.toArray(parcelables);
-      playerIntent.putExtra(
-          PlayerActivity.MANIFEST_FILTER_EXTRA, new ParcelableArray<>(parcelables));
+      Parcelable[] keysArray = keys.toArray(new Parcelable[selectedTrackIndices.length]);
+      playerIntent.putExtra(PlayerActivity.MANIFEST_FILTER_EXTRA, new ParcelableArray<>(keysArray));
     }
     startActivity(playerIntent);
   }
 
-  private void updateRepresentationsList() {
-    if (manifestDownloaderTask != null) {
-      manifestDownloaderTask.cancel(true);
-    }
-    manifestDownloaderTask = new ManifestDownloaderTask().execute();
-  }
-
-  private ArrayList<Object> getSelectedRepresentationKeys() {
-    SparseBooleanArray checked = representationList.getCheckedItemPositions();
-    ArrayList<Object> representations = new ArrayList<>(checked.size());
-    for (int i = 0; i < checked.size(); i++) {
-      if (checked.valueAt(i)) {
-        int position = checked.keyAt(i);
-        RepresentationItem item =
-            (RepresentationItem) representationList.getItemAtPosition(position);
-        representations.add(item.key);
+  private int[] getSelectedTrackIndices() {
+    ArrayList<Integer> checkedIndices = new ArrayList<>();
+    for (int i = 0; i < representationList.getChildCount(); i++) {
+      if (representationList.isItemChecked(i)) {
+        checkedIndices.add(i);
       }
     }
-    return representations;
+    return Util.toArray(checkedIndices);
   }
 
-  private static final class RepresentationItem {
+  private abstract static class DownloadHelper<K extends Parcelable> {
 
-    public final Parcelable key;
-    public final String title;
+    protected static final Format DUMMY_FORMAT =
+        Format.createContainerFormat(null, null, null, null, Format.NO_VALUE, 0, null);
 
-    public RepresentationItem(Parcelable key, String title) {
-      this.key = key;
-      this.title = title;
+    protected final Uri uri;
+    protected final DataSource.Factory dataSourceFactory;
+    protected final List<Format> trackFormats;
+    protected final List<K> trackKeys;
+
+    public DownloadHelper(Uri uri, DataSource.Factory dataSourceFactory) {
+      this.uri = uri;
+      this.dataSourceFactory = dataSourceFactory;
+      trackFormats = new ArrayList<>();
+      trackKeys = new ArrayList<>();
     }
 
-    @Override
-    public String toString() {
-      return title;
+    public abstract void init() throws IOException;
+
+    public int getTrackCount() {
+      return trackFormats.size();
     }
-  }
 
-  private final class ManifestDownloaderTask
-      extends AsyncTask<Void, Void, List<RepresentationItem>> {
+    public Format getTrackFormat(int trackIndex) {
+      return trackFormats.get(trackIndex);
+    }
 
-    @Override
-    protected List<RepresentationItem> doInBackground(Void... ignore) {
-      try {
-        return downloadUtilMethods.loadRepresentationItems(trackNameProvider);
-      } catch (IOException | InterruptedException e) {
-        return null;
+    public List<K> getTrackKeys(int... trackIndices) {
+      if (trackFormats.size() == 1 && trackFormats.get(0) == DUMMY_FORMAT) {
+        return Collections.emptyList();
       }
-    }
-
-    @Override
-    protected void onPostExecute(List<RepresentationItem> items) {
-      if (items == null) {
-        Toast.makeText(
-                getApplicationContext(), R.string.download_manifest_load_error, Toast.LENGTH_LONG)
-            .show();
-        return;
-      }
-      arrayAdapter.clear();
-      for (RepresentationItem representationItem : items) {
-        arrayAdapter.add(representationItem);
+      List<K> keys = new ArrayList<>(trackIndices.length);
+      for (int trackIndex : trackIndices) {
+        keys.add(trackKeys.get(trackIndex));
       }
+      return keys;
     }
-  }
-
-  private abstract static class DownloadUtilMethods {
-
-    protected final Uri manifestUri;
-
-    public DownloadUtilMethods(Uri manifestUri) {
-      this.manifestUri = manifestUri;
-    }
-
-    public abstract List<RepresentationItem> loadRepresentationItems(
-        TrackNameProvider trackNameProvider) throws IOException, InterruptedException;
 
     public abstract DownloadAction getDownloadAction(
-        boolean isRemoveAction, String sampleName, List<Object> representationKeys);
+        boolean isRemoveAction, String sampleName, int... trackIndices);
   }
 
-  private static final class DashDownloadUtilMethods extends DownloadUtilMethods {
+  private static final class DashDownloadHelper extends DownloadHelper<RepresentationKey> {
 
-    private final DataSource.Factory manifestDataSourceFactory;
-
-    public DashDownloadUtilMethods(Uri manifestUri, DataSource.Factory manifestDataSourceFactory) {
-      super(manifestUri);
-      this.manifestDataSourceFactory = manifestDataSourceFactory;
+    public DashDownloadHelper(Uri uri, DataSource.Factory dataSourceFactory) {
+      super(uri, dataSourceFactory);
     }
 
     @Override
-    public List<RepresentationItem> loadRepresentationItems(TrackNameProvider trackNameProvider)
-        throws IOException, InterruptedException {
-      DataSource dataSource = manifestDataSourceFactory.createDataSource();
-      DashManifest manifest =
-          ParsingLoadable.load(dataSource, new DashManifestParser(), manifestUri);
+    public void init() throws IOException {
+      DataSource dataSource = dataSourceFactory.createDataSource();
+      DashManifest manifest = ParsingLoadable.load(dataSource, new DashManifestParser(), uri);
 
-      ArrayList<RepresentationItem> items = new ArrayList<>();
       for (int periodIndex = 0; periodIndex < manifest.getPeriodCount(); periodIndex++) {
         List<AdaptationSet> adaptationSets = manifest.getPeriod(periodIndex).adaptationSets;
         for (int adaptationIndex = 0; adaptationIndex < adaptationSets.size(); adaptationIndex++) {
@@ -287,119 +265,98 @@ public class DownloadActivity extends Activity {
               adaptationSets.get(adaptationIndex).representations;
           int representationsCount = representations.size();
           for (int i = 0; i < representationsCount; i++) {
-            RepresentationKey key = new RepresentationKey(periodIndex, adaptationIndex, i);
-            String trackName = trackNameProvider.getTrackName(representations.get(i).format);
-            items.add(new RepresentationItem(key, trackName));
+            trackFormats.add(representations.get(i).format);
+            trackKeys.add(new RepresentationKey(periodIndex, adaptationIndex, i));
           }
         }
       }
-      return items;
     }
 
     @Override
     public DownloadAction getDownloadAction(
-        boolean isRemoveAction, String sampleName, List<Object> representationKeys) {
-      RepresentationKey[] keys =
-          representationKeys.toArray(new RepresentationKey[representationKeys.size()]);
-      return new DashDownloadAction(isRemoveAction, sampleName, manifestUri, keys);
+        boolean isRemoveAction, String sampleName, int... trackIndices) {
+      return new DashDownloadAction(uri, isRemoveAction, sampleName, getTrackKeys(trackIndices));
     }
-
   }
 
-  private static final class HlsDownloadUtilMethods extends DownloadUtilMethods {
+  private static final class HlsDownloadHelper extends DownloadHelper<RenditionKey> {
 
-    private final DataSource.Factory manifestDataSourceFactory;
-
-    public HlsDownloadUtilMethods(Uri manifestUri, DataSource.Factory manifestDataSourceFactory) {
-      super(manifestUri);
-      this.manifestDataSourceFactory = manifestDataSourceFactory;
+    public HlsDownloadHelper(Uri uri, DataSource.Factory dataSourceFactory) {
+      super(uri, dataSourceFactory);
     }
 
     @Override
-    public List<RepresentationItem> loadRepresentationItems(TrackNameProvider trackNameProvider)
-        throws IOException, InterruptedException {
-      DataSource dataSource = manifestDataSourceFactory.createDataSource();
-      HlsPlaylist<?> playlist =
-          ParsingLoadable.load(dataSource, new HlsPlaylistParser(), manifestUri);
+    public void init() throws IOException {
+      DataSource dataSource = dataSourceFactory.createDataSource();
+      HlsPlaylist<?> playlist = ParsingLoadable.load(dataSource, new HlsPlaylistParser(), uri);
 
-      ArrayList<RepresentationItem> items = new ArrayList<>();
       if (playlist instanceof HlsMediaPlaylist) {
-        items.add(new RepresentationItem(null, "Stream"));
+        trackFormats.add(DUMMY_FORMAT);
       } else {
         HlsMasterPlaylist masterPlaylist = (HlsMasterPlaylist) playlist;
-        addRepresentationItems(masterPlaylist.variants, RenditionKey.GROUP_VARIANTS, items);
-        addRepresentationItems(masterPlaylist.audios, RenditionKey.GROUP_AUDIOS, items);
-        addRepresentationItems(masterPlaylist.subtitles, RenditionKey.GROUP_SUBTITLES, items);
+        addRepresentationItems(masterPlaylist.variants, RenditionKey.GROUP_VARIANTS);
+        addRepresentationItems(masterPlaylist.audios, RenditionKey.GROUP_AUDIOS);
+        addRepresentationItems(masterPlaylist.subtitles, RenditionKey.GROUP_SUBTITLES);
       }
-      return items;
     }
 
-    private void addRepresentationItems(
-        List<HlsUrl> renditions, int renditionGroup, List<RepresentationItem> out) {
+    private void addRepresentationItems(List<HlsUrl> renditions, int renditionGroup) {
       for (int i = 0; i < renditions.size(); i++) {
-        out.add(new RepresentationItem(new RenditionKey(renditionGroup, i), renditions.get(i).url));
+        trackFormats.add(renditions.get(i).format);
+        trackKeys.add(new RenditionKey(renditionGroup, i));
       }
     }
 
     @Override
     public DownloadAction getDownloadAction(
-        boolean isRemoveAction, String sampleName, List<Object> representationKeys) {
-      RenditionKey[] keys = representationKeys.toArray(new RenditionKey[representationKeys.size()]);
-      return new HlsDownloadAction(isRemoveAction, sampleName, manifestUri, keys);
+        boolean isRemoveAction, String sampleName, int... trackIndices) {
+      return new HlsDownloadAction(uri, isRemoveAction, sampleName, getTrackKeys(trackIndices));
     }
   }
 
-  private static final class SsDownloadUtilMethods extends DownloadUtilMethods {
+  private static final class SsDownloadHelper extends DownloadHelper<TrackKey> {
 
-    private final DataSource.Factory manifestDataSourceFactory;
-
-    public SsDownloadUtilMethods(Uri manifestUri, DataSource.Factory manifestDataSourceFactory) {
-      super(manifestUri);
-      this.manifestDataSourceFactory = manifestDataSourceFactory;
+    public SsDownloadHelper(Uri uri, DataSource.Factory dataSourceFactory) {
+      super(uri, dataSourceFactory);
     }
 
     @Override
-    public List<RepresentationItem> loadRepresentationItems(TrackNameProvider trackNameProvider)
-        throws IOException, InterruptedException {
-      DataSource dataSource = manifestDataSourceFactory.createDataSource();
-      SsManifest manifest = ParsingLoadable.load(dataSource, new SsManifestParser(), manifestUri);
+    public void init() throws IOException {
+      DataSource dataSource = dataSourceFactory.createDataSource();
+      SsManifest manifest = ParsingLoadable.load(dataSource, new SsManifestParser(), uri);
 
-      ArrayList<RepresentationItem> items = new ArrayList<>();
       for (int i = 0; i < manifest.streamElements.length; i++) {
         SsManifest.StreamElement streamElement = manifest.streamElements[i];
         for (int j = 0; j < streamElement.formats.length; j++) {
-          TrackKey key = new TrackKey(i, j);
-          String trackName = trackNameProvider.getTrackName(streamElement.formats[j]);
-          items.add(new RepresentationItem(key, trackName));
+          trackFormats.add(streamElement.formats[j]);
+          trackKeys.add(new TrackKey(i, j));
         }
       }
-      return items;
     }
 
     @Override
     public DownloadAction getDownloadAction(
-        boolean isRemoveAction, String sampleName, List<Object> representationKeys) {
-      TrackKey[] keys = representationKeys.toArray(new TrackKey[representationKeys.size()]);
-      return new SsDownloadAction(isRemoveAction, sampleName, manifestUri, keys);
+        boolean isRemoveAction, String sampleName, int... trackIndices) {
+      return new SsDownloadAction(uri, isRemoveAction, sampleName, getTrackKeys(trackIndices));
     }
   }
 
-  private static final class ProgressiveDownloadUtilMethods extends DownloadUtilMethods {
+  private static final class ProgressiveDownloadHelper extends DownloadHelper<Parcelable> {
 
-    public ProgressiveDownloadUtilMethods(Uri manifestUri) {
-      super(manifestUri);
+    public ProgressiveDownloadHelper(Uri uri) {
+      super(uri, null);
     }
 
     @Override
-    public List<RepresentationItem> loadRepresentationItems(TrackNameProvider trackNameProvider) {
-      return Collections.singletonList(new RepresentationItem(null, "Stream"));
+    public void init() {
+      trackFormats.add(DUMMY_FORMAT);
     }
 
     @Override
     public DownloadAction getDownloadAction(
-        boolean isRemoveAction, String sampleName, List<Object> representationKeys) {
+        boolean isRemoveAction, String sampleName, int... trackIndices) {
       return new ProgressiveDownloadAction(
-          isRemoveAction, sampleName, manifestUri, /* customCacheKey= */ null);
+          uri, isRemoveAction, sampleName, /* customCacheKey= */ null);
     }
   }
 }
diff --git a/demos/main/src/main/res/layout/downloader_activity.xml b/demos/main/src/main/res/layout/downloader_activity.xml
index 1b1432be5b..220dcda7ea 100644
--- a/demos/main/src/main/res/layout/downloader_activity.xml
+++ b/demos/main/src/main/res/layout/downloader_activity.xml
@@ -37,12 +37,6 @@
         android:onClick="onClick"
         android:text="@string/download_remove_all"/>
 
-    <Button android:id="@+id/refresh_button"
-        android:layout_width="wrap_content"
-        android:layout_height="wrap_content"
-        android:onClick="onClick"
-        android:text="@string/download_refresh"/>
-
     <Button android:id="@+id/play_button"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
diff --git a/demos/main/src/main/res/values/strings.xml b/demos/main/src/main/res/values/strings.xml
index 1164af8cf5..24251b17ca 100644
--- a/demos/main/src/main/res/values/strings.xml
+++ b/demos/main/src/main/res/values/strings.xml
@@ -51,8 +51,6 @@
 
   <string name="download_remove_all">Remove all</string>
 
-  <string name="download_refresh">Refresh</string>
-
   <string name="download_only_single_period_non_drm_protected">Currently only downloading of single period non-DRM protected content is demonstrated in this app.</string>
 
 </resources>
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/offline/DownloadAction.java b/library/core/src/main/java/com/google/android/exoplayer2/offline/DownloadAction.java
index 126a42cef5..3fd59a17a5 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/offline/DownloadAction.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/offline/DownloadAction.java
@@ -15,6 +15,7 @@
  */
 package com.google.android.exoplayer2.offline;
 
+import android.net.Uri;
 import android.support.annotation.Nullable;
 import java.io.ByteArrayOutputStream;
 import java.io.DataInputStream;
@@ -90,21 +91,25 @@ public abstract class DownloadAction {
   public final String type;
   /** The action version. */
   public final int version;
+  /** The uri being downloaded or removed. */
+  public final Uri uri;
   /** Whether this is a remove action. If false, this is a download action. */
   public final boolean isRemoveAction;
-  /** Custom data for this action. May be the empty string if no custom data was specified. */
+  /** Custom data for this action, or the empty string if no custom data was specified. */
   public final String data;
 
   /**
    * @param type The type of the action.
    * @param version The action version.
+   * @param uri The uri being downloaded or removed.
    * @param isRemoveAction Whether this is a remove action. If false, this is a download action.
-   * @param data Optional custom data for this action. If null, an empty string is used.
+   * @param data Optional custom data for this action.
    */
   protected DownloadAction(
-      String type, int version, boolean isRemoveAction, @Nullable String data) {
+      String type, int version, Uri uri, boolean isRemoveAction, @Nullable String data) {
     this.type = type;
     this.version = version;
+    this.uri = uri;
     this.isRemoveAction = isRemoveAction;
     this.data = data != null ? data : "";
   }
@@ -121,12 +126,14 @@ public abstract class DownloadAction {
     return output.toByteArray();
   }
 
+  /** Returns whether this is an action for the same media as the {@code other}. */
+  public boolean isSameMedia(DownloadAction other) {
+    return uri.equals(other.uri);
+  }
+
   /** Serializes itself into the {@code output}. */
   protected abstract void writeToStream(DataOutputStream output) throws IOException;
 
-  /** Returns whether this is an action for the same media as the {@code other}. */
-  protected abstract boolean isSameMedia(DownloadAction other);
-
   /** Creates a {@link Downloader} with the given parameters. */
   protected abstract Downloader createDownloader(
       DownloaderConstructorHelper downloaderConstructorHelper);
@@ -137,13 +144,18 @@ public abstract class DownloadAction {
       return false;
     }
     DownloadAction that = (DownloadAction) o;
-    return data.equals(that.data) && isRemoveAction == that.isRemoveAction;
+    return type.equals(that.type)
+        && version == that.version
+        && uri.equals(that.uri)
+        && isRemoveAction == that.isRemoveAction
+        && data.equals(that.data);
   }
 
   @Override
   public int hashCode() {
-    int result = data.hashCode();
+    int result = uri.hashCode();
     result = 31 * result + (isRemoveAction ? 1 : 0);
+    result = 31 * result + data.hashCode();
     return result;
   }
 
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/offline/ProgressiveDownloadAction.java b/library/core/src/main/java/com/google/android/exoplayer2/offline/ProgressiveDownloadAction.java
index 4ccca775ef..a287c0adcd 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/offline/ProgressiveDownloadAction.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/offline/ProgressiveDownloadAction.java
@@ -18,7 +18,6 @@ package com.google.android.exoplayer2.offline;
 import android.net.Uri;
 import android.support.annotation.Nullable;
 import com.google.android.exoplayer2.upstream.cache.CacheUtil;
-import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Util;
 import java.io.DataInputStream;
 import java.io.DataOutputStream;
@@ -27,7 +26,7 @@ import java.io.IOException;
 /** An action to download or remove downloaded progressive streams. */
 public final class ProgressiveDownloadAction extends DownloadAction {
 
-  private static final String TYPE = "ProgressiveDownloadAction";
+  private static final String TYPE = "progressive";
   private static final int VERSION = 0;
 
   public static final Deserializer DESERIALIZER =
@@ -35,28 +34,26 @@ public final class ProgressiveDownloadAction extends DownloadAction {
         @Override
         public ProgressiveDownloadAction readFromStream(int version, DataInputStream input)
             throws IOException {
+          Uri uri = Uri.parse(input.readUTF());
           boolean isRemoveAction = input.readBoolean();
           String data = input.readUTF();
-          Uri uri = Uri.parse(input.readUTF());
           String customCacheKey = input.readBoolean() ? input.readUTF() : null;
-          return new ProgressiveDownloadAction(isRemoveAction, data, uri, customCacheKey);
+          return new ProgressiveDownloadAction(uri, isRemoveAction, data, customCacheKey);
         }
       };
 
-  private final Uri uri;
-  private final @Nullable String customCacheKey;
+  public final @Nullable String customCacheKey;
 
   /**
+   * @param uri Uri of the data to be downloaded.
    * @param isRemoveAction Whether this is a remove action. If false, this is a download action.
    * @param data Optional custom data for this action. If null, an empty string is used.
-   * @param uri Uri of the data to be downloaded.
    * @param customCacheKey A custom key that uniquely identifies the original stream. If not null it
    *     is used for cache indexing.
    */
   public ProgressiveDownloadAction(
-      boolean isRemoveAction, @Nullable String data, Uri uri, @Nullable String customCacheKey) {
-    super(TYPE, VERSION, isRemoveAction, data);
-    this.uri = Assertions.checkNotNull(uri);
+      Uri uri, boolean isRemoveAction, @Nullable String data, @Nullable String customCacheKey) {
+    super(TYPE, VERSION, uri, isRemoveAction, data);
     this.customCacheKey = customCacheKey;
   }
 
@@ -67,9 +64,9 @@ public final class ProgressiveDownloadAction extends DownloadAction {
 
   @Override
   protected void writeToStream(DataOutputStream output) throws IOException {
+    output.writeUTF(uri.toString());
     output.writeBoolean(isRemoveAction);
     output.writeUTF(data);
-    output.writeUTF(uri.toString());
     boolean customCacheKeySet = customCacheKey != null;
     output.writeBoolean(customCacheKeySet);
     if (customCacheKeySet) {
@@ -78,11 +75,9 @@ public final class ProgressiveDownloadAction extends DownloadAction {
   }
 
   @Override
-  protected boolean isSameMedia(DownloadAction other) {
-    if (!(other instanceof ProgressiveDownloadAction)) {
-      return false;
-    }
-    return getCacheKey().equals(((ProgressiveDownloadAction) other).getCacheKey());
+  public boolean isSameMedia(DownloadAction other) {
+    return ((other instanceof ProgressiveDownloadAction)
+        && getCacheKey().equals(((ProgressiveDownloadAction) other).getCacheKey()));
   }
 
   @Override
@@ -94,13 +89,12 @@ public final class ProgressiveDownloadAction extends DownloadAction {
       return false;
     }
     ProgressiveDownloadAction that = (ProgressiveDownloadAction) o;
-    return uri.equals(that.uri) && Util.areEqual(customCacheKey, that.customCacheKey);
+    return Util.areEqual(customCacheKey, that.customCacheKey);
   }
 
   @Override
   public int hashCode() {
     int result = super.hashCode();
-    result = 31 * result + uri.hashCode();
     result = 31 * result + (customCacheKey != null ? customCacheKey.hashCode() : 0);
     return result;
   }
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/offline/SegmentDownloadAction.java b/library/core/src/main/java/com/google/android/exoplayer2/offline/SegmentDownloadAction.java
index c51393fc44..0b7a3220e4 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/offline/SegmentDownloadAction.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/offline/SegmentDownloadAction.java
@@ -21,14 +21,16 @@ import com.google.android.exoplayer2.util.Assertions;
 import java.io.DataInputStream;
 import java.io.DataOutputStream;
 import java.io.IOException;
-import java.util.Arrays;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
 
 /**
  * {@link DownloadAction} for {@link SegmentDownloader}s.
  *
  * @param <K> The type of the representation key object.
  */
-public abstract class SegmentDownloadAction<K extends Comparable> extends DownloadAction {
+public abstract class SegmentDownloadAction<K extends Comparable<K>> extends DownloadAction {
 
   /**
    * Base class for {@link SegmentDownloadAction} {@link Deserializer}s.
@@ -44,78 +46,68 @@ public abstract class SegmentDownloadAction<K extends Comparable> extends Downlo
     @Override
     public final DownloadAction readFromStream(int version, DataInputStream input)
         throws IOException {
+      Uri uri = Uri.parse(input.readUTF());
       boolean isRemoveAction = input.readBoolean();
       String data = input.readUTF();
-      Uri manifestUri = Uri.parse(input.readUTF());
       int keyCount = input.readInt();
-      K[] keys = createKeyArray(keyCount);
+      List<K> keys = new ArrayList<>();
       for (int i = 0; i < keyCount; i++) {
-        keys[i] = readKey(input);
+        keys.add(readKey(input));
       }
-      return createDownloadAction(isRemoveAction, data, manifestUri, keys);
+      return createDownloadAction(uri, isRemoveAction, data, keys);
     }
 
     /** Deserializes a key from the {@code input}. */
     protected abstract K readKey(DataInputStream input) throws IOException;
 
-    /** Returns a key array. */
-    protected abstract K[] createKeyArray(int keyCount);
-
     /** Returns a {@link DownloadAction}. */
     protected abstract DownloadAction createDownloadAction(
-        boolean isRemoveAction, String data, Uri manifestUri, K[] keys);
+        Uri manifestUri, boolean isRemoveAction, String data, List<K> keys);
   }
 
-  protected final Uri manifestUri;
-  protected final K[] keys;
+  public final List<K> keys;
 
   /**
    * @param type The type of the action.
    * @param version The action version.
+   * @param uri The URI of the media being downloaded.
    * @param isRemoveAction Whether the data will be removed. If {@code false} it will be downloaded.
-   * @param data Optional custom data for this action. If null, an empty string is used.
-   * @param manifestUri The {@link Uri} of the manifest to be downloaded.
-   * @param keys Keys of representations to be downloaded. If empty, all representations are
-   *     downloaded. If {@code removeAction} is true, {@code keys} must be an empty array.
+   * @param data Optional custom data for this action.
+   * @param keys Keys of tracks to be downloaded. If empty, all tracks will be downloaded. If {@code
+   *     removeAction} is true, {@code keys} must be empty.
    */
   protected SegmentDownloadAction(
       String type,
       int version,
+      Uri uri,
       boolean isRemoveAction,
       @Nullable String data,
-      Uri manifestUri,
-      K[] keys) {
-    super(type, version, isRemoveAction, data);
-    this.manifestUri = manifestUri;
+      List<K> keys) {
+    super(type, version, uri, isRemoveAction, data);
     if (isRemoveAction) {
-      Assertions.checkArgument(keys.length == 0);
-      this.keys = keys;
+      Assertions.checkArgument(keys.isEmpty());
+      this.keys = Collections.emptyList();
     } else {
-      this.keys = keys.clone();
-      Arrays.sort(this.keys);
+      ArrayList<K> mutableKeys = new ArrayList<>(keys);
+      Collections.sort(mutableKeys);
+      this.keys = Collections.unmodifiableList(mutableKeys);
     }
   }
 
   @Override
   public final void writeToStream(DataOutputStream output) throws IOException {
+    output.writeUTF(uri.toString());
     output.writeBoolean(isRemoveAction);
     output.writeUTF(data);
-    output.writeUTF(manifestUri.toString());
-    output.writeInt(keys.length);
-    for (K key : keys) {
-      writeKey(output, key);
+    output.writeInt(keys.size());
+    for (int i = 0; i < keys.size(); i++) {
+      writeKey(output, keys.get(i));
     }
   }
 
   /** Serializes the {@code key} into the {@code output}. */
   protected abstract void writeKey(DataOutputStream output, K key) throws IOException;
 
-  @Override
-  public boolean isSameMedia(DownloadAction other) {
-    return other instanceof SegmentDownloadAction
-        && manifestUri.equals(((SegmentDownloadAction<?>) other).manifestUri);
-  }
-
   @Override
   public boolean equals(Object o) {
     if (this == o) {
@@ -125,14 +117,13 @@ public abstract class SegmentDownloadAction<K extends Comparable> extends Downlo
       return false;
     }
     SegmentDownloadAction<?> that = (SegmentDownloadAction<?>) o;
-    return manifestUri.equals(that.manifestUri) && Arrays.equals(keys, that.keys);
+    return keys.equals(that.keys);
   }
 
   @Override
   public int hashCode() {
     int result = super.hashCode();
-    result = 31 * result + manifestUri.hashCode();
-    result = 31 * result + Arrays.hashCode(keys);
+    result = 31 * result + keys.hashCode();
     return result;
   }
 
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/offline/SegmentDownloader.java b/library/core/src/main/java/com/google/android/exoplayer2/offline/SegmentDownloader.java
index 915da3f073..30250d6e75 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/offline/SegmentDownloader.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/offline/SegmentDownloader.java
@@ -17,7 +17,6 @@ package com.google.android.exoplayer2.offline;
 
 import android.net.Uri;
 import android.support.annotation.NonNull;
-import android.support.annotation.Nullable;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.upstream.DataSource;
 import com.google.android.exoplayer2.upstream.DataSpec;
@@ -77,20 +76,16 @@ public abstract class SegmentDownloader<M extends FilterableManifest<M, K>, K>
   /**
    * @param manifestUri The {@link Uri} of the manifest to be downloaded.
    * @param constructorHelper a {@link DownloaderConstructorHelper} instance.
-   * @param trackKeys Track keys to select when downloading. If null or empty, all tracks are
-   *     downloaded.
+   * @param trackKeys Track keys to select when downloading. If empty, all tracks are downloaded.
    */
   public SegmentDownloader(
-      Uri manifestUri, DownloaderConstructorHelper constructorHelper, @Nullable K[] trackKeys) {
+      Uri manifestUri, DownloaderConstructorHelper constructorHelper, List<K> trackKeys) {
     this.manifestUri = manifestUri;
     this.cache = constructorHelper.getCache();
     this.dataSource = constructorHelper.buildCacheDataSource(false);
     this.offlineDataSource = constructorHelper.buildCacheDataSource(true);
     this.priorityTaskManager = constructorHelper.getPriorityTaskManager();
-    keys = new ArrayList<>();
-    if (trackKeys != null) {
-      Collections.addAll(this.keys, trackKeys);
-    }
+    keys = new ArrayList<>(trackKeys);
     totalSegments = C.LENGTH_UNSET;
   }
 
diff --git a/library/core/src/test/java/com/google/android/exoplayer2/offline/ActionFileTest.java b/library/core/src/test/java/com/google/android/exoplayer2/offline/ActionFileTest.java
index 3fd794f16b..28ee39a46e 100644
--- a/library/core/src/test/java/com/google/android/exoplayer2/offline/ActionFileTest.java
+++ b/library/core/src/test/java/com/google/android/exoplayer2/offline/ActionFileTest.java
@@ -17,6 +17,7 @@ package com.google.android.exoplayer2.offline;
 
 import static com.google.common.truth.Truth.assertThat;
 
+import android.net.Uri;
 import com.google.android.exoplayer2.offline.DownloadAction.Deserializer;
 import com.google.android.exoplayer2.util.Util;
 import java.io.DataInputStream;
@@ -236,7 +237,7 @@ public class ActionFileTest {
     public static final int VERSION = 0;
 
     private FakeDownloadAction(String type, String data) {
-      super(type, VERSION, /* isRemoveAction= */ false, data);
+      super(type, VERSION, Uri.parse("http://test.com"), /* isRemoveAction= */ false, data);
     }
 
     @Override
@@ -244,37 +245,11 @@ public class ActionFileTest {
       output.writeUTF(data);
     }
 
-    @Override
-    protected boolean isSameMedia(DownloadAction other) {
-      return false;
-    }
-
     @Override
     protected Downloader createDownloader(DownloaderConstructorHelper downloaderConstructorHelper) {
       return null;
     }
 
-    // auto generated code
-
-    @Override
-    public boolean equals(Object o) {
-      if (this == o) {
-        return true;
-      }
-      if (o == null || getClass() != o.getClass()) {
-        return false;
-      }
-      FakeDownloadAction that = (FakeDownloadAction) o;
-      return version == that.version && data.equals(that.data) && type.equals(that.type);
-    }
-
-    @Override
-    public int hashCode() {
-      int result = type.hashCode();
-      result = 31 * result + version;
-      result = 31 * result + data.hashCode();
-      return result;
-    }
   }
 
 }
diff --git a/library/core/src/test/java/com/google/android/exoplayer2/offline/DownloadManagerTest.java b/library/core/src/test/java/com/google/android/exoplayer2/offline/DownloadManagerTest.java
index 53cb7e3cdf..39f0a0fb18 100644
--- a/library/core/src/test/java/com/google/android/exoplayer2/offline/DownloadManagerTest.java
+++ b/library/core/src/test/java/com/google/android/exoplayer2/offline/DownloadManagerTest.java
@@ -18,8 +18,8 @@ package com.google.android.exoplayer2.offline;
 import static com.google.common.truth.Truth.assertThat;
 import static org.junit.Assert.fail;
 
+import android.net.Uri;
 import android.os.ConditionVariable;
-import android.support.annotation.Nullable;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.offline.DownloadManager.DownloadListener;
 import com.google.android.exoplayer2.offline.DownloadManager.TaskState;
@@ -62,14 +62,20 @@ public class DownloadManagerTest {
 
   private static final int MIN_RETRY_COUNT = 3;
 
-  private DownloadManager downloadManager;
+  private Uri uri1;
+  private Uri uri2;
+  private Uri uri3;
+  private DummyMainThread dummyMainThread;
   private File actionFile;
   private TestDownloadListener testDownloadListener;
-  private DummyMainThread dummyMainThread;
+  private DownloadManager downloadManager;
 
   @Before
   public void setUp() throws Exception {
     MockitoAnnotations.initMocks(this);
+    uri1 = Uri.parse("http://abc.com/media1");
+    uri2 = Uri.parse("http://abc.com/media2");
+    uri3 = Uri.parse("http://abc.com/media3");
     dummyMainThread = new DummyMainThread();
     actionFile = Util.createTempFile(RuntimeEnvironment.application, "ExoPlayerTest");
     testDownloadListener = new TestDownloadListener();
@@ -85,17 +91,17 @@ public class DownloadManagerTest {
 
   @Test
   public void testDownloadActionRuns() throws Throwable {
-    doTestActionRuns(createDownloadAction("media 1"));
+    doTestActionRuns(createDownloadAction(uri1));
   }
 
   @Test
   public void testRemoveActionRuns() throws Throwable {
-    doTestActionRuns(createRemoveAction("media 1"));
+    doTestActionRuns(createRemoveAction(uri1));
   }
 
   @Test
   public void testDownloadRetriesThenFails() throws Throwable {
-    FakeDownloadAction downloadAction = createDownloadAction("media 1");
+    FakeDownloadAction downloadAction = createDownloadAction(uri1);
     downloadAction.post();
     FakeDownloader fakeDownloader = downloadAction.getFakeDownloader();
     fakeDownloader.enableDownloadIOException = true;
@@ -110,11 +116,11 @@ public class DownloadManagerTest {
 
   @Test
   public void testDownloadNoRetryWhenCanceled() throws Throwable {
-    FakeDownloadAction downloadAction = createDownloadAction("media 1").ignoreInterrupts();
+    FakeDownloadAction downloadAction = createDownloadAction(uri1).ignoreInterrupts();
     downloadAction.getFakeDownloader().enableDownloadIOException = true;
     downloadAction.post().assertStarted();
 
-    FakeDownloadAction removeAction = createRemoveAction("media 1").post();
+    FakeDownloadAction removeAction = createRemoveAction(uri1).post();
 
     downloadAction.unblock().assertCanceled();
     removeAction.unblock();
@@ -124,7 +130,7 @@ public class DownloadManagerTest {
 
   @Test
   public void testDownloadRetriesThenContinues() throws Throwable {
-    FakeDownloadAction downloadAction = createDownloadAction("media 1");
+    FakeDownloadAction downloadAction = createDownloadAction(uri1);
     downloadAction.post();
     FakeDownloader fakeDownloader = downloadAction.getFakeDownloader();
     fakeDownloader.enableDownloadIOException = true;
@@ -143,7 +149,7 @@ public class DownloadManagerTest {
   @Test
   @SuppressWarnings({"NonAtomicVolatileUpdate", "NonAtomicOperationOnVolatileField"})
   public void testDownloadRetryCountResetsOnProgress() throws Throwable {
-    FakeDownloadAction downloadAction = createDownloadAction("media 1");
+    FakeDownloadAction downloadAction = createDownloadAction(uri1);
     downloadAction.post();
     FakeDownloader fakeDownloader = downloadAction.getFakeDownloader();
     fakeDownloader.enableDownloadIOException = true;
@@ -163,41 +169,41 @@ public class DownloadManagerTest {
 
   @Test
   public void testDifferentMediaDownloadActionsStartInParallel() throws Throwable {
-    doTestActionsRunInParallel(createDownloadAction("media 1"), createDownloadAction("media 2"));
+    doTestActionsRunInParallel(createDownloadAction(uri1), createDownloadAction(uri2));
   }
 
   @Test
   public void testDifferentMediaDifferentActionsStartInParallel() throws Throwable {
-    doTestActionsRunInParallel(createDownloadAction("media 1"), createRemoveAction("media 2"));
+    doTestActionsRunInParallel(createDownloadAction(uri1), createRemoveAction(uri2));
   }
 
   @Test
   public void testSameMediaDownloadActionsStartInParallel() throws Throwable {
-    doTestActionsRunInParallel(createDownloadAction("media 1"), createDownloadAction("media 1"));
+    doTestActionsRunInParallel(createDownloadAction(uri1), createDownloadAction(uri1));
   }
 
   @Test
   public void testSameMediaRemoveActionWaitsDownloadAction() throws Throwable {
-    doTestActionsRunSequentially(createDownloadAction("media 1"), createRemoveAction("media 1"));
+    doTestActionsRunSequentially(createDownloadAction(uri1), createRemoveAction(uri1));
   }
 
   @Test
   public void testSameMediaDownloadActionWaitsRemoveAction() throws Throwable {
-    doTestActionsRunSequentially(createRemoveAction("media 1"), createDownloadAction("media 1"));
+    doTestActionsRunSequentially(createRemoveAction(uri1), createDownloadAction(uri1));
   }
 
   @Test
   public void testSameMediaRemoveActionWaitsRemoveAction() throws Throwable {
-    doTestActionsRunSequentially(createRemoveAction("media 1"), createRemoveAction("media 1"));
+    doTestActionsRunSequentially(createRemoveAction(uri1), createRemoveAction(uri1));
   }
 
   @Test
   public void testSameMediaMultipleActions() throws Throwable {
-    FakeDownloadAction downloadAction1 = createDownloadAction("media 1").ignoreInterrupts();
-    FakeDownloadAction downloadAction2 = createDownloadAction("media 1").ignoreInterrupts();
-    FakeDownloadAction removeAction1 = createRemoveAction("media 1");
-    FakeDownloadAction downloadAction3 = createDownloadAction("media 1");
-    FakeDownloadAction removeAction2 = createRemoveAction("media 1");
+    FakeDownloadAction downloadAction1 = createDownloadAction(uri1).ignoreInterrupts();
+    FakeDownloadAction downloadAction2 = createDownloadAction(uri1).ignoreInterrupts();
+    FakeDownloadAction removeAction1 = createRemoveAction(uri1);
+    FakeDownloadAction downloadAction3 = createDownloadAction(uri1);
+    FakeDownloadAction removeAction2 = createRemoveAction(uri1);
 
     // Two download actions run in parallel.
     downloadAction1.post().assertStarted();
@@ -229,9 +235,9 @@ public class DownloadManagerTest {
 
   @Test
   public void testMultipleRemoveActionWaitsLastCancelsAllOther() throws Throwable {
-    FakeDownloadAction removeAction1 = createRemoveAction("media 1").ignoreInterrupts();
-    FakeDownloadAction removeAction2 = createRemoveAction("media 1");
-    FakeDownloadAction removeAction3 = createRemoveAction("media 1");
+    FakeDownloadAction removeAction1 = createRemoveAction(uri1).ignoreInterrupts();
+    FakeDownloadAction removeAction2 = createRemoveAction(uri1);
+    FakeDownloadAction removeAction3 = createRemoveAction(uri1);
 
     removeAction1.post().assertStarted();
     removeAction2.post().assertDoesNotStart();
@@ -247,9 +253,9 @@ public class DownloadManagerTest {
 
   @Test
   public void testGetTasks() throws Throwable {
-    FakeDownloadAction removeAction = createRemoveAction("media 1");
-    FakeDownloadAction downloadAction1 = createDownloadAction("media 1");
-    FakeDownloadAction downloadAction2 = createDownloadAction("media 1");
+    FakeDownloadAction removeAction = createRemoveAction(uri1);
+    FakeDownloadAction downloadAction1 = createDownloadAction(uri1);
+    FakeDownloadAction downloadAction2 = createDownloadAction(uri1);
 
     removeAction.post().assertStarted();
     downloadAction1.post().assertDoesNotStart();
@@ -264,9 +270,9 @@ public class DownloadManagerTest {
 
   @Test
   public void testMultipleWaitingDownloadActionStartsInParallel() throws Throwable {
-    FakeDownloadAction removeAction = createRemoveAction("media 1");
-    FakeDownloadAction downloadAction1 = createDownloadAction("media 1");
-    FakeDownloadAction downloadAction2 = createDownloadAction("media 1");
+    FakeDownloadAction removeAction = createRemoveAction(uri1);
+    FakeDownloadAction downloadAction1 = createDownloadAction(uri1);
+    FakeDownloadAction downloadAction2 = createDownloadAction(uri1);
 
     removeAction.post().assertStarted();
     downloadAction1.post().assertDoesNotStart();
@@ -283,9 +289,9 @@ public class DownloadManagerTest {
 
   @Test
   public void testDifferentMediaDownloadActionsPreserveOrder() throws Throwable {
-    FakeDownloadAction removeAction = createRemoveAction("media 1").ignoreInterrupts();
-    FakeDownloadAction downloadAction1 = createDownloadAction("media 1");
-    FakeDownloadAction downloadAction2 = createDownloadAction("media 2");
+    FakeDownloadAction removeAction = createRemoveAction(uri1).ignoreInterrupts();
+    FakeDownloadAction downloadAction1 = createDownloadAction(uri1);
+    FakeDownloadAction downloadAction2 = createDownloadAction(uri2);
 
     removeAction.post().assertStarted();
     downloadAction1.post().assertDoesNotStart();
@@ -302,9 +308,9 @@ public class DownloadManagerTest {
 
   @Test
   public void testDifferentMediaRemoveActionsDoNotPreserveOrder() throws Throwable {
-    FakeDownloadAction downloadAction = createDownloadAction("media 1").ignoreInterrupts();
-    FakeDownloadAction removeAction1 = createRemoveAction("media 1");
-    FakeDownloadAction removeAction2 = createRemoveAction("media 2");
+    FakeDownloadAction downloadAction = createDownloadAction(uri1).ignoreInterrupts();
+    FakeDownloadAction removeAction1 = createRemoveAction(uri1);
+    FakeDownloadAction removeAction2 = createRemoveAction(uri2);
 
     downloadAction.post().assertStarted();
     removeAction1.post().assertDoesNotStart();
@@ -321,11 +327,11 @@ public class DownloadManagerTest {
 
   @Test
   public void testStopAndResume() throws Throwable {
-    FakeDownloadAction download1Action = createDownloadAction("media 1");
-    FakeDownloadAction remove2Action = createRemoveAction("media 2");
-    FakeDownloadAction download2Action = createDownloadAction("media 2");
-    FakeDownloadAction remove1Action = createRemoveAction("media 1");
-    FakeDownloadAction download3Action = createDownloadAction("media 3");
+    FakeDownloadAction download1Action = createDownloadAction(uri1);
+    FakeDownloadAction remove2Action = createRemoveAction(uri2);
+    FakeDownloadAction download2Action = createDownloadAction(uri2);
+    FakeDownloadAction remove1Action = createRemoveAction(uri1);
+    FakeDownloadAction download3Action = createDownloadAction(uri3);
 
     download1Action.post().assertStarted();
     remove2Action.post().assertStarted();
@@ -371,9 +377,9 @@ public class DownloadManagerTest {
   @Test
   public void testResumeBeforeTotallyStopped() throws Throwable {
     setUpDownloadManager(2);
-    FakeDownloadAction download1Action = createDownloadAction("media 1").ignoreInterrupts();
-    FakeDownloadAction download2Action = createDownloadAction("media 2");
-    FakeDownloadAction download3Action = createDownloadAction("media 3");
+    FakeDownloadAction download1Action = createDownloadAction(uri1).ignoreInterrupts();
+    FakeDownloadAction download2Action = createDownloadAction(uri2);
+    FakeDownloadAction download3Action = createDownloadAction(uri3);
 
     download1Action.post().assertStarted();
     download2Action.post().assertStarted();
@@ -481,12 +487,12 @@ public class DownloadManagerTest {
     testDownloadListener.blockUntilTasksCompleteAndThrowAnyDownloadError();
   }
 
-  private FakeDownloadAction createDownloadAction(String mediaId) {
-    return new FakeDownloadAction(/* isRemoveAction= */ false, mediaId);
+  private FakeDownloadAction createDownloadAction(Uri uri) {
+    return new FakeDownloadAction(uri, /* isRemoveAction= */ false);
   }
 
-  private FakeDownloadAction createRemoveAction(String mediaId) {
-    return new FakeDownloadAction(/* isRemoveAction= */ true, mediaId);
+  private FakeDownloadAction createRemoveAction(Uri uri) {
+    return new FakeDownloadAction(uri, /* isRemoveAction= */ true);
   }
 
   private void runOnMainThread(final Runnable r) throws Throwable {
@@ -530,28 +536,20 @@ public class DownloadManagerTest {
 
   private class FakeDownloadAction extends DownloadAction {
 
-    private final String mediaId;
     private final FakeDownloader downloader;
     private final BlockingQueue<Integer> states;
 
-    private FakeDownloadAction(boolean isRemoveAction, @Nullable String mediaId) {
-      super("FakeDownloadAction", /* version= */ 0, isRemoveAction, mediaId);
-      this.mediaId = mediaId;
+    private FakeDownloadAction(Uri uri, boolean isRemoveAction) {
+      super("Fake", /* version= */ 0, uri, isRemoveAction, /* data= */ null);
       this.downloader = new FakeDownloader(isRemoveAction);
       this.states = new ArrayBlockingQueue<>(10);
     }
 
     @Override
-    protected void writeToStream(DataOutputStream output) throws IOException {
+    protected void writeToStream(DataOutputStream output) {
       // do nothing.
     }
 
-    @Override
-    protected boolean isSameMedia(DownloadAction other) {
-      return other instanceof FakeDownloadAction
-          && mediaId.equals(((FakeDownloadAction) other).mediaId);
-    }
-
     @Override
     protected Downloader createDownloader(DownloaderConstructorHelper downloaderConstructorHelper) {
       return downloader;
diff --git a/library/core/src/test/java/com/google/android/exoplayer2/offline/ProgressiveDownloadActionTest.java b/library/core/src/test/java/com/google/android/exoplayer2/offline/ProgressiveDownloadActionTest.java
index 81e061b3df..bc3732e3d3 100644
--- a/library/core/src/test/java/com/google/android/exoplayer2/offline/ProgressiveDownloadActionTest.java
+++ b/library/core/src/test/java/com/google/android/exoplayer2/offline/ProgressiveDownloadActionTest.java
@@ -49,20 +49,20 @@ public class ProgressiveDownloadActionTest {
 
   @Test
   public void testDownloadActionIsNotRemoveAction() throws Exception {
-    ProgressiveDownloadAction action = new ProgressiveDownloadAction(false, null, uri1, null);
+    ProgressiveDownloadAction action = new ProgressiveDownloadAction(uri1, false, null, null);
     assertThat(action.isRemoveAction).isFalse();
   }
 
   @Test
   public void testRemoveActionisRemoveAction() throws Exception {
-    ProgressiveDownloadAction action2 = new ProgressiveDownloadAction(true, null, uri1, null);
+    ProgressiveDownloadAction action2 = new ProgressiveDownloadAction(uri1, true, null, null);
     assertThat(action2.isRemoveAction).isTrue();
   }
 
   @Test
   public void testCreateDownloader() throws Exception {
     MockitoAnnotations.initMocks(this);
-    ProgressiveDownloadAction action = new ProgressiveDownloadAction(false, null, uri1, null);
+    ProgressiveDownloadAction action = new ProgressiveDownloadAction(uri1, false, null, null);
     DownloaderConstructorHelper constructorHelper = new DownloaderConstructorHelper(
         Mockito.mock(Cache.class), DummyDataSource.FACTORY);
     assertThat(action.createDownloader(constructorHelper)).isNotNull();
@@ -70,75 +70,75 @@ public class ProgressiveDownloadActionTest {
 
   @Test
   public void testSameUriCacheKeyDifferentAction_IsSameMedia() throws Exception {
-    ProgressiveDownloadAction action1 = new ProgressiveDownloadAction(true, null, uri1, null);
-    ProgressiveDownloadAction action2 = new ProgressiveDownloadAction(false, null, uri1, null);
+    ProgressiveDownloadAction action1 = new ProgressiveDownloadAction(uri1, true, null, null);
+    ProgressiveDownloadAction action2 = new ProgressiveDownloadAction(uri1, false, null, null);
     assertSameMedia(action1, action2);
   }
 
   @Test
   public void testNullCacheKeyDifferentUriAction_IsNotSameMedia() throws Exception {
-    ProgressiveDownloadAction action3 = new ProgressiveDownloadAction(true, null, uri2, null);
-    ProgressiveDownloadAction action4 = new ProgressiveDownloadAction(false, null, uri1, null);
+    ProgressiveDownloadAction action3 = new ProgressiveDownloadAction(uri2, true, null, null);
+    ProgressiveDownloadAction action4 = new ProgressiveDownloadAction(uri1, false, null, null);
     assertNotSameMedia(action3, action4);
   }
 
   @Test
   public void testSameCacheKeyDifferentUriAction_IsSameMedia() throws Exception {
-    ProgressiveDownloadAction action5 = new ProgressiveDownloadAction(true, null, uri2, "key");
-    ProgressiveDownloadAction action6 = new ProgressiveDownloadAction(false, null, uri1, "key");
+    ProgressiveDownloadAction action5 = new ProgressiveDownloadAction(uri2, true, null, "key");
+    ProgressiveDownloadAction action6 = new ProgressiveDownloadAction(uri1, false, null, "key");
     assertSameMedia(action5, action6);
   }
 
   @Test
   public void testSameUriDifferentCacheKeyAction_IsNotSameMedia() throws Exception {
-    ProgressiveDownloadAction action7 = new ProgressiveDownloadAction(true, null, uri1, "key");
-    ProgressiveDownloadAction action8 = new ProgressiveDownloadAction(false, null, uri1, "key2");
+    ProgressiveDownloadAction action7 = new ProgressiveDownloadAction(uri1, true, null, "key");
+    ProgressiveDownloadAction action8 = new ProgressiveDownloadAction(uri1, false, null, "key2");
     assertNotSameMedia(action7, action8);
   }
 
   @Test
   public void testSameUriNullCacheKeyAction_IsNotSameMedia() throws Exception {
-    ProgressiveDownloadAction action1 = new ProgressiveDownloadAction(true, null, uri1, "key");
-    ProgressiveDownloadAction action2 = new ProgressiveDownloadAction(false, null, uri1, null);
+    ProgressiveDownloadAction action1 = new ProgressiveDownloadAction(uri1, true, null, "key");
+    ProgressiveDownloadAction action2 = new ProgressiveDownloadAction(uri1, false, null, null);
     assertNotSameMedia(action1, action2);
   }
 
   @Test
   public void testEquals() throws Exception {
-    ProgressiveDownloadAction action1 = new ProgressiveDownloadAction(true, null, uri1, null);
+    ProgressiveDownloadAction action1 = new ProgressiveDownloadAction(uri1, true, null, null);
     assertThat(action1.equals(action1)).isTrue();
 
-    ProgressiveDownloadAction action2 = new ProgressiveDownloadAction(true, null, uri1, null);
-    ProgressiveDownloadAction action3 = new ProgressiveDownloadAction(true, null, uri1, null);
+    ProgressiveDownloadAction action2 = new ProgressiveDownloadAction(uri1, true, null, null);
+    ProgressiveDownloadAction action3 = new ProgressiveDownloadAction(uri1, true, null, null);
     assertThat(action2.equals(action3)).isTrue();
 
-    ProgressiveDownloadAction action4 = new ProgressiveDownloadAction(true, null, uri1, null);
-    ProgressiveDownloadAction action5 = new ProgressiveDownloadAction(false, null, uri1, null);
+    ProgressiveDownloadAction action4 = new ProgressiveDownloadAction(uri1, true, null, null);
+    ProgressiveDownloadAction action5 = new ProgressiveDownloadAction(uri1, false, null, null);
     assertThat(action4.equals(action5)).isFalse();
 
-    ProgressiveDownloadAction action6 = new ProgressiveDownloadAction(true, null, uri1, null);
-    ProgressiveDownloadAction action7 = new ProgressiveDownloadAction(true, null, uri1, "key");
+    ProgressiveDownloadAction action6 = new ProgressiveDownloadAction(uri1, true, null, null);
+    ProgressiveDownloadAction action7 = new ProgressiveDownloadAction(uri1, true, null, "key");
     assertThat(action6.equals(action7)).isFalse();
 
-    ProgressiveDownloadAction action8 = new ProgressiveDownloadAction(true, null, uri1, "key2");
-    ProgressiveDownloadAction action9 = new ProgressiveDownloadAction(true, null, uri1, "key");
+    ProgressiveDownloadAction action8 = new ProgressiveDownloadAction(uri1, true, null, "key2");
+    ProgressiveDownloadAction action9 = new ProgressiveDownloadAction(uri1, true, null, "key");
     assertThat(action8.equals(action9)).isFalse();
 
-    ProgressiveDownloadAction action10 = new ProgressiveDownloadAction(true, null, uri1, null);
-    ProgressiveDownloadAction action11 = new ProgressiveDownloadAction(true, null, uri2, null);
+    ProgressiveDownloadAction action10 = new ProgressiveDownloadAction(uri1, true, null, null);
+    ProgressiveDownloadAction action11 = new ProgressiveDownloadAction(uri2, true, null, null);
     assertThat(action10.equals(action11)).isFalse();
   }
 
   @Test
   public void testSerializerGetType() throws Exception {
-    ProgressiveDownloadAction action = new ProgressiveDownloadAction(false, null, uri1, null);
+    ProgressiveDownloadAction action = new ProgressiveDownloadAction(uri1, false, null, null);
     assertThat(action.type).isNotNull();
   }
 
   @Test
   public void testSerializerWriteRead() throws Exception {
-    doTestSerializationRoundTrip(new ProgressiveDownloadAction(false, null, uri1, null));
-    doTestSerializationRoundTrip(new ProgressiveDownloadAction(true, null, uri2, "key"));
+    doTestSerializationRoundTrip(new ProgressiveDownloadAction(uri1, false, null, null));
+    doTestSerializationRoundTrip(new ProgressiveDownloadAction(uri2, true, null, "key"));
   }
 
   private void assertSameMedia(
diff --git a/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/offline/DashDownloadAction.java b/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/offline/DashDownloadAction.java
index 61e063cf91..8ebd137009 100644
--- a/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/offline/DashDownloadAction.java
+++ b/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/offline/DashDownloadAction.java
@@ -24,11 +24,12 @@ import com.google.android.exoplayer2.source.dash.manifest.RepresentationKey;
 import java.io.DataInputStream;
 import java.io.DataOutputStream;
 import java.io.IOException;
+import java.util.List;
 
 /** An action to download or remove downloaded DASH streams. */
 public final class DashDownloadAction extends SegmentDownloadAction<RepresentationKey> {
 
-  private static final String TYPE = "DashDownloadAction";
+  private static final String TYPE = "dash";
   private static final int VERSION = 0;
 
   public static final Deserializer DESERIALIZER =
@@ -39,30 +40,28 @@ public final class DashDownloadAction extends SegmentDownloadAction<Representati
           return new RepresentationKey(input.readInt(), input.readInt(), input.readInt());
         }
 
-        @Override
-        protected RepresentationKey[] createKeyArray(int keyCount) {
-          return new RepresentationKey[keyCount];
-        }
-
         @Override
         protected DownloadAction createDownloadAction(
-            boolean isRemoveAction, String data, Uri manifestUri, RepresentationKey[] keys) {
-          return new DashDownloadAction(isRemoveAction, data, manifestUri, keys);
+            Uri uri, boolean isRemoveAction, String data, List<RepresentationKey> keys) {
+          return new DashDownloadAction(uri, isRemoveAction, data, keys);
         }
       };
 
   /**
-   * @see SegmentDownloadAction#SegmentDownloadAction(String, int, boolean, String, Uri,
-   *     Comparable[])
+   * @param uri The DASH manifest URI.
+   * @param isRemoveAction Whether the data will be removed. If {@code false} it will be downloaded.
+   * @param data Optional custom data for this action. If null, an empty string is used.
+   * @param keys Keys of representations to be downloaded. If empty, all representations are
+   *     downloaded. If {@code removeAction} is true, {@code keys} must be empty.
    */
   public DashDownloadAction(
-      boolean isRemoveAction, @Nullable String data, Uri manifestUri, RepresentationKey... keys) {
-    super(TYPE, VERSION, isRemoveAction, data, manifestUri, keys);
+      Uri uri, boolean isRemoveAction, @Nullable String data, List<RepresentationKey> keys) {
+    super(TYPE, VERSION, uri, isRemoveAction, data, keys);
   }
 
   @Override
   protected DashDownloader createDownloader(DownloaderConstructorHelper constructorHelper) {
-    return new DashDownloader(manifestUri, constructorHelper, keys);
+    return new DashDownloader(uri, constructorHelper, keys);
   }
 
   @Override
diff --git a/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/offline/DashDownloader.java b/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/offline/DashDownloader.java
index b7c94731c8..7bc26d5ea3 100644
--- a/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/offline/DashDownloader.java
+++ b/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/offline/DashDownloader.java
@@ -49,8 +49,11 @@ import java.util.List;
  *     new DownloaderConstructorHelper(cache, factory);
  * // Create a downloader for the first representation of the first adaptation set of the first
  * // period.
- * DashDownloader dashDownloader = new DashDownloader(
- *     manifestUrl, constructorHelper, new RepresentationKey[] {new RepresentationKey(0, 0, 0)});
+ * DashDownloader dashDownloader =
+ *     new DashDownloader(
+ *         manifestUrl,
+ *         constructorHelper,
+ *         Collections.singletonList(new RepresentationKey(0, 0, 0)));
  * // Perform the download.
  * dashDownloader.download();
  * // Access downloaded data using CacheDataSource
@@ -60,11 +63,11 @@ import java.util.List;
  */
 public final class DashDownloader extends SegmentDownloader<DashManifest, RepresentationKey> {
 
-  /** @see SegmentDownloader#SegmentDownloader(Uri, DownloaderConstructorHelper, Object[]) */
+  /** @see SegmentDownloader#SegmentDownloader(Uri, DownloaderConstructorHelper, List) */
   public DashDownloader(
       Uri manifestUri,
       DownloaderConstructorHelper constructorHelper,
-      @Nullable RepresentationKey[] trackKeys) {
+      List<RepresentationKey> trackKeys) {
     super(manifestUri, constructorHelper, trackKeys);
   }
 
diff --git a/library/dash/src/test/java/com/google/android/exoplayer2/source/dash/offline/DashDownloadActionTest.java b/library/dash/src/test/java/com/google/android/exoplayer2/source/dash/offline/DashDownloadActionTest.java
index 5ec952fb10..0a14b2a2c2 100644
--- a/library/dash/src/test/java/com/google/android/exoplayer2/source/dash/offline/DashDownloadActionTest.java
+++ b/library/dash/src/test/java/com/google/android/exoplayer2/source/dash/offline/DashDownloadActionTest.java
@@ -28,6 +28,8 @@ import java.io.ByteArrayOutputStream;
 import java.io.DataInputStream;
 import java.io.DataOutputStream;
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collections;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -51,141 +53,120 @@ public class DashDownloadActionTest {
   }
 
   @Test
-  public void testDownloadActionIsNotRemoveAction() throws Exception {
-    DashDownloadAction action =
-        new DashDownloadAction(/* isRemoveAction= */ false, /* data= */ null, uri1);
+  public void testDownloadActionIsNotRemoveAction() {
+    DashDownloadAction action = newAction(uri1, /* isRemoveAction= */ false, /* data= */ null);
     assertThat(action.isRemoveAction).isFalse();
   }
 
   @Test
-  public void testRemoveActionisRemoveAction() throws Exception {
-    DashDownloadAction action2 =
-        new DashDownloadAction(/* isRemoveAction= */ true, /* data= */ null, uri1);
+  public void testRemoveActionisRemoveAction() {
+    DashDownloadAction action2 = newAction(uri1, /* isRemoveAction= */ true, /* data= */ null);
     assertThat(action2.isRemoveAction).isTrue();
   }
 
   @Test
-  public void testCreateDownloader() throws Exception {
+  public void testCreateDownloader() {
     MockitoAnnotations.initMocks(this);
-    DashDownloadAction action =
-        new DashDownloadAction(/* isRemoveAction= */ false, /* data= */ null, uri1);
+    DashDownloadAction action = newAction(uri1, /* isRemoveAction= */ false, /* data= */ null);
     DownloaderConstructorHelper constructorHelper = new DownloaderConstructorHelper(
         Mockito.mock(Cache.class), DummyDataSource.FACTORY);
     assertThat(action.createDownloader(constructorHelper)).isNotNull();
   }
 
   @Test
-  public void testSameUriDifferentAction_IsSameMedia() throws Exception {
-    DashDownloadAction action1 =
-        new DashDownloadAction(/* isRemoveAction= */ true, /* data= */ null, uri1);
-    DashDownloadAction action2 =
-        new DashDownloadAction(/* isRemoveAction= */ false, /* data= */ null, uri1);
+  public void testSameUriDifferentAction_IsSameMedia() {
+    DashDownloadAction action1 = newAction(uri1, /* isRemoveAction= */ true, /* data= */ null);
+    DashDownloadAction action2 = newAction(uri1, /* isRemoveAction= */ false, /* data= */ null);
     assertThat(action1.isSameMedia(action2)).isTrue();
   }
 
   @Test
-  public void testDifferentUriAndAction_IsNotSameMedia() throws Exception {
-    DashDownloadAction action3 =
-        new DashDownloadAction(/* isRemoveAction= */ true, /* data= */ null, uri2);
-    DashDownloadAction action4 =
-        new DashDownloadAction(/* isRemoveAction= */ false, /* data= */ null, uri1);
+  public void testDifferentUriAndAction_IsNotSameMedia() {
+    DashDownloadAction action3 = newAction(uri2, /* isRemoveAction= */ true, /* data= */ null);
+    DashDownloadAction action4 = newAction(uri1, /* isRemoveAction= */ false, /* data= */ null);
     assertThat(action3.isSameMedia(action4)).isFalse();
   }
 
   @SuppressWarnings("EqualsWithItself")
   @Test
-  public void testEquals() throws Exception {
-    DashDownloadAction action1 =
-        new DashDownloadAction(/* isRemoveAction= */ true, /* data= */ null, uri1);
+  public void testEquals() {
+    DashDownloadAction action1 = newAction(uri1, /* isRemoveAction= */ true, /* data= */ null);
     assertThat(action1.equals(action1)).isTrue();
 
-    DashDownloadAction action2 =
-        new DashDownloadAction(/* isRemoveAction= */ true, /* data= */ null, uri1);
-    DashDownloadAction action3 =
-        new DashDownloadAction(/* isRemoveAction= */ true, /* data= */ null, uri1);
+    DashDownloadAction action2 = newAction(uri1, /* isRemoveAction= */ true, /* data= */ null);
+    DashDownloadAction action3 = newAction(uri1, /* isRemoveAction= */ true, /* data= */ null);
     assertEqual(action2, action3);
 
-    DashDownloadAction action4 =
-        new DashDownloadAction(/* isRemoveAction= */ true, /* data= */ null, uri1);
-    DashDownloadAction action5 =
-        new DashDownloadAction(/* isRemoveAction= */ false, /* data= */ null, uri1);
+    DashDownloadAction action4 = newAction(uri1, /* isRemoveAction= */ true, /* data= */ null);
+    DashDownloadAction action5 = newAction(uri1, /* isRemoveAction= */ false, /* data= */ null);
     assertNotEqual(action4, action5);
 
-    DashDownloadAction action6 =
-        new DashDownloadAction(/* isRemoveAction= */ false, /* data= */ null, uri1);
+    DashDownloadAction action6 = newAction(uri1, /* isRemoveAction= */ false, /* data= */ null);
     DashDownloadAction action7 =
-        new DashDownloadAction(
-            /* isRemoveAction= */ false, /* data= */ null, uri1, new RepresentationKey(0, 0, 0));
+        newAction(
+            uri1, /* isRemoveAction= */ false, /* data= */ null, new RepresentationKey(0, 0, 0));
     assertNotEqual(action6, action7);
 
     DashDownloadAction action8 =
-        new DashDownloadAction(
-            /* isRemoveAction= */ false, /* data= */ null, uri1, new RepresentationKey(1, 1, 1));
+        newAction(
+            uri1, /* isRemoveAction= */ false, /* data= */ null, new RepresentationKey(1, 1, 1));
     DashDownloadAction action9 =
-        new DashDownloadAction(
-            /* isRemoveAction= */ false, /* data= */ null, uri1, new RepresentationKey(0, 0, 0));
+        newAction(
+            uri1, /* isRemoveAction= */ false, /* data= */ null, new RepresentationKey(0, 0, 0));
     assertNotEqual(action8, action9);
 
-    DashDownloadAction action10 =
-        new DashDownloadAction(/* isRemoveAction= */ true, /* data= */ null, uri1);
-    DashDownloadAction action11 =
-        new DashDownloadAction(/* isRemoveAction= */ true, /* data= */ null, uri2);
+    DashDownloadAction action10 = newAction(uri1, /* isRemoveAction= */ true, /* data= */ null);
+    DashDownloadAction action11 = newAction(uri2, /* isRemoveAction= */ true, /* data= */ null);
     assertNotEqual(action10, action11);
 
     DashDownloadAction action12 =
-        new DashDownloadAction(
+        newAction(
+            uri1,
             /* isRemoveAction= */ false,
             /* data= */ null,
-            uri1,
             new RepresentationKey(0, 0, 0),
             new RepresentationKey(1, 1, 1));
     DashDownloadAction action13 =
-        new DashDownloadAction(
+        newAction(
+            uri1,
             /* isRemoveAction= */ false,
             /* data= */ null,
-            uri1,
             new RepresentationKey(1, 1, 1),
             new RepresentationKey(0, 0, 0));
     assertEqual(action12, action13);
 
     DashDownloadAction action14 =
-        new DashDownloadAction(
-            /* isRemoveAction= */ false, /* data= */ null, uri1, new RepresentationKey(0, 0, 0));
+        newAction(
+            uri1, /* isRemoveAction= */ false, /* data= */ null, new RepresentationKey(0, 0, 0));
     DashDownloadAction action15 =
-        new DashDownloadAction(
+        newAction(
+            uri1,
             /* isRemoveAction= */ false,
             /* data= */ null,
-            uri1,
             new RepresentationKey(1, 1, 1),
             new RepresentationKey(0, 0, 0));
     assertNotEqual(action14, action15);
 
-    DashDownloadAction action16 =
-        new DashDownloadAction(/* isRemoveAction= */ false, /* data= */ null, uri1);
-    DashDownloadAction action17 =
-        new DashDownloadAction(
-            /* isRemoveAction= */ false, /* data= */ null, uri1, new RepresentationKey[0]);
+    DashDownloadAction action16 = newAction(uri1, /* isRemoveAction= */ false, /* data= */ null);
+    DashDownloadAction action17 = newAction(uri1, /* isRemoveAction= */ false, /* data= */ null);
     assertEqual(action16, action17);
   }
 
   @Test
-  public void testSerializerGetType() throws Exception {
-    DashDownloadAction action =
-        new DashDownloadAction(/* isRemoveAction= */ false, /* data= */ null, uri1);
+  public void testSerializerGetType() {
+    DashDownloadAction action = newAction(uri1, /* isRemoveAction= */ false, /* data= */ null);
     assertThat(action.type).isNotNull();
   }
 
   @Test
   public void testSerializerWriteRead() throws Exception {
+    doTestSerializationRoundTrip(newAction(uri1, /* isRemoveAction= */ false, /* data= */ null));
+    doTestSerializationRoundTrip(newAction(uri1, /* isRemoveAction= */ true, /* data= */ null));
     doTestSerializationRoundTrip(
-        new DashDownloadAction(/* isRemoveAction= */ false, /* data= */ null, uri1));
-    doTestSerializationRoundTrip(
-        new DashDownloadAction(/* isRemoveAction= */ true, /* data= */ null, uri1));
-    doTestSerializationRoundTrip(
-        new DashDownloadAction(
+        newAction(
+            uri2,
             /* isRemoveAction= */ false,
             /* data= */ null,
-            uri2,
             new RepresentationKey(0, 0, 0),
             new RepresentationKey(1, 1, 1)));
   }
@@ -214,4 +195,10 @@ public class DashDownloadActionTest {
     assertThat(action).isEqualTo(action2);
   }
 
+  private static DashDownloadAction newAction(
+      Uri uri, boolean isRemoveAction, String data, RepresentationKey... keys) {
+    ArrayList<RepresentationKey> keysList = new ArrayList<>();
+    Collections.addAll(keysList, keys);
+    return new DashDownloadAction(uri, isRemoveAction, data, keysList);
+  }
 }
diff --git a/library/dash/src/test/java/com/google/android/exoplayer2/source/dash/offline/DashDownloaderTest.java b/library/dash/src/test/java/com/google/android/exoplayer2/source/dash/offline/DashDownloaderTest.java
index a38f920b83..a096a4d4c2 100644
--- a/library/dash/src/test/java/com/google/android/exoplayer2/source/dash/offline/DashDownloaderTest.java
+++ b/library/dash/src/test/java/com/google/android/exoplayer2/source/dash/offline/DashDownloaderTest.java
@@ -38,6 +38,8 @@ import com.google.android.exoplayer2.upstream.cache.SimpleCache;
 import com.google.android.exoplayer2.util.Util;
 import java.io.File;
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collections;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
@@ -302,7 +304,14 @@ public class DashDownloaderTest {
   }
 
   private DashDownloader getDashDownloader(Factory factory, RepresentationKey... keys) {
-    return new DashDownloader(TEST_MPD_URI, new DownloaderConstructorHelper(cache, factory), keys);
+    return new DashDownloader(
+        TEST_MPD_URI, new DownloaderConstructorHelper(cache, factory), keysList(keys));
+  }
+
+  private static ArrayList<RepresentationKey> keysList(RepresentationKey... keys) {
+    ArrayList<RepresentationKey> keysList = new ArrayList<>();
+    Collections.addAll(keysList, keys);
+    return keysList;
   }
 
 }
diff --git a/library/dash/src/test/java/com/google/android/exoplayer2/source/dash/offline/DownloadManagerDashTest.java b/library/dash/src/test/java/com/google/android/exoplayer2/source/dash/offline/DownloadManagerDashTest.java
index 44df905a44..3b6d4d0136 100644
--- a/library/dash/src/test/java/com/google/android/exoplayer2/source/dash/offline/DownloadManagerDashTest.java
+++ b/library/dash/src/test/java/com/google/android/exoplayer2/source/dash/offline/DownloadManagerDashTest.java
@@ -22,6 +22,7 @@ import static com.google.android.exoplayer2.testutil.CacheAsserts.assertCachedDa
 import static com.google.common.truth.Truth.assertThat;
 
 import android.content.Context;
+import android.net.Uri;
 import android.os.ConditionVariable;
 import com.google.android.exoplayer2.offline.DownloadManager;
 import com.google.android.exoplayer2.offline.DownloaderConstructorHelper;
@@ -36,6 +37,8 @@ import com.google.android.exoplayer2.upstream.cache.NoOpCacheEvictor;
 import com.google.android.exoplayer2.upstream.cache.SimpleCache;
 import com.google.android.exoplayer2.util.Util;
 import java.io.File;
+import java.util.ArrayList;
+import java.util.Collections;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Ignore;
@@ -244,11 +247,11 @@ public class DownloadManagerDashTest {
   }
 
   private void handleDownloadAction(RepresentationKey... keys) {
-    downloadManager.handleAction(new DashDownloadAction(false, null, TEST_MPD_URI, keys));
+    downloadManager.handleAction(newAction(TEST_MPD_URI, false, null, keys));
   }
 
   private void handleRemoveAction() {
-    downloadManager.handleAction(new DashDownloadAction(true, null, TEST_MPD_URI));
+    downloadManager.handleAction(newAction(TEST_MPD_URI, true, null));
   }
 
   private void createDownloadManager() {
@@ -272,4 +275,11 @@ public class DownloadManagerDashTest {
           }
         });
   }
+
+  private static DashDownloadAction newAction(
+      Uri uri, boolean isRemoveAction, String data, RepresentationKey... keys) {
+    ArrayList<RepresentationKey> keysList = new ArrayList<>();
+    Collections.addAll(keysList, keys);
+    return new DashDownloadAction(uri, isRemoveAction, data, keysList);
+  }
 }
diff --git a/library/dash/src/test/java/com/google/android/exoplayer2/source/dash/offline/DownloadServiceDashTest.java b/library/dash/src/test/java/com/google/android/exoplayer2/source/dash/offline/DownloadServiceDashTest.java
index 1118e1fac6..bd375aac03 100644
--- a/library/dash/src/test/java/com/google/android/exoplayer2/source/dash/offline/DownloadServiceDashTest.java
+++ b/library/dash/src/test/java/com/google/android/exoplayer2/source/dash/offline/DownloadServiceDashTest.java
@@ -23,6 +23,7 @@ import static com.google.android.exoplayer2.testutil.CacheAsserts.assertCachedDa
 import android.app.Notification;
 import android.content.Context;
 import android.content.Intent;
+import android.net.Uri;
 import android.support.annotation.Nullable;
 import com.google.android.exoplayer2.offline.DownloadManager;
 import com.google.android.exoplayer2.offline.DownloadManager.TaskState;
@@ -43,6 +44,8 @@ import com.google.android.exoplayer2.util.ConditionVariable;
 import com.google.android.exoplayer2.util.Util;
 import java.io.File;
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collections;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Ignore;
@@ -219,11 +222,11 @@ public class DownloadServiceDashTest {
   }
 
   private void removeAll() throws Throwable {
-    callDownloadServiceOnStart(new DashDownloadAction(true, null, TEST_MPD_URI));
+    callDownloadServiceOnStart(newAction(TEST_MPD_URI, true, null));
   }
 
-  private void downloadKeys(RepresentationKey... keys) throws Throwable {
-    callDownloadServiceOnStart(new DashDownloadAction(false, null, TEST_MPD_URI, keys));
+  private void downloadKeys(RepresentationKey... keys) {
+    callDownloadServiceOnStart(newAction(TEST_MPD_URI, false, null, keys));
   }
 
   private void callDownloadServiceOnStart(final DashDownloadAction action) {
@@ -238,4 +241,11 @@ public class DownloadServiceDashTest {
           }
         });
   }
+
+  private static DashDownloadAction newAction(
+      Uri uri, boolean isRemoveAction, String data, RepresentationKey... keys) {
+    ArrayList<RepresentationKey> keysList = new ArrayList<>();
+    Collections.addAll(keysList, keys);
+    return new DashDownloadAction(uri, isRemoveAction, data, keysList);
+  }
 }
diff --git a/library/hls/src/main/java/com/google/android/exoplayer2/source/hls/offline/HlsDownloadAction.java b/library/hls/src/main/java/com/google/android/exoplayer2/source/hls/offline/HlsDownloadAction.java
index c4578853f5..4bb05bae74 100644
--- a/library/hls/src/main/java/com/google/android/exoplayer2/source/hls/offline/HlsDownloadAction.java
+++ b/library/hls/src/main/java/com/google/android/exoplayer2/source/hls/offline/HlsDownloadAction.java
@@ -24,11 +24,12 @@ import com.google.android.exoplayer2.source.hls.playlist.RenditionKey;
 import java.io.DataInputStream;
 import java.io.DataOutputStream;
 import java.io.IOException;
+import java.util.List;
 
 /** An action to download or remove downloaded HLS streams. */
 public final class HlsDownloadAction extends SegmentDownloadAction<RenditionKey> {
 
-  private static final String TYPE = "HlsDownloadAction";
+  private static final String TYPE = "hls";
   private static final int VERSION = 0;
 
   public static final Deserializer DESERIALIZER =
@@ -41,30 +42,28 @@ public final class HlsDownloadAction extends SegmentDownloadAction<RenditionKey>
           return new RenditionKey(renditionGroup, trackIndex);
         }
 
-        @Override
-        protected RenditionKey[] createKeyArray(int keyCount) {
-          return new RenditionKey[keyCount];
-        }
-
         @Override
         protected DownloadAction createDownloadAction(
-            boolean isRemoveAction, String data, Uri manifestUri, RenditionKey[] keys) {
-          return new HlsDownloadAction(isRemoveAction, data, manifestUri, keys);
+            Uri uri, boolean isRemoveAction, String data, List<RenditionKey> keys) {
+          return new HlsDownloadAction(uri, isRemoveAction, data, keys);
         }
       };
 
   /**
-   * @see SegmentDownloadAction#SegmentDownloadAction(String, int, boolean, String, Uri,
-   *     Comparable[])
+   * @param uri The HLS playlist URI.
+   * @param isRemoveAction Whether the data will be removed. If {@code false} it will be downloaded.
+   * @param data Optional custom data for this action.
+   * @param keys Keys of renditions to be downloaded. If empty, all renditions are downloaded. If
+   *     {@code removeAction} is true, {@code keys} must empty.
    */
   public HlsDownloadAction(
-      boolean isRemoveAction, @Nullable String data, Uri manifestUri, RenditionKey... keys) {
-    super(TYPE, VERSION, isRemoveAction, data, manifestUri, keys);
+      Uri uri, boolean isRemoveAction, @Nullable String data, List<RenditionKey> keys) {
+    super(TYPE, VERSION, uri, isRemoveAction, data, keys);
   }
 
   @Override
   protected HlsDownloader createDownloader(DownloaderConstructorHelper constructorHelper) {
-    return new HlsDownloader(manifestUri, constructorHelper, keys);
+    return new HlsDownloader(uri, constructorHelper, keys);
   }
 
   @Override
diff --git a/library/hls/src/main/java/com/google/android/exoplayer2/source/hls/offline/HlsDownloader.java b/library/hls/src/main/java/com/google/android/exoplayer2/source/hls/offline/HlsDownloader.java
index a46ca91997..9b06d81ff4 100644
--- a/library/hls/src/main/java/com/google/android/exoplayer2/source/hls/offline/HlsDownloader.java
+++ b/library/hls/src/main/java/com/google/android/exoplayer2/source/hls/offline/HlsDownloader.java
@@ -37,9 +37,11 @@ import java.util.List;
 /** A downloader for HLS streams. */
 public final class HlsDownloader extends SegmentDownloader<HlsMasterPlaylist, RenditionKey> {
 
-  /** @see SegmentDownloader#SegmentDownloader(Uri, DownloaderConstructorHelper, Object[]) */
+  /** @see SegmentDownloader#SegmentDownloader(Uri, DownloaderConstructorHelper, List) */
   public HlsDownloader(
-      Uri manifestUri, DownloaderConstructorHelper constructorHelper, RenditionKey[] trackKeys) {
+      Uri manifestUri,
+      DownloaderConstructorHelper constructorHelper,
+      List<RenditionKey> trackKeys) {
     super(manifestUri, constructorHelper, trackKeys);
   }
 
diff --git a/library/hls/src/test/java/com/google/android/exoplayer2/source/hls/offline/HlsDownloaderTest.java b/library/hls/src/test/java/com/google/android/exoplayer2/source/hls/offline/HlsDownloaderTest.java
index 8af5119776..342f7a0ab0 100644
--- a/library/hls/src/test/java/com/google/android/exoplayer2/source/hls/offline/HlsDownloaderTest.java
+++ b/library/hls/src/test/java/com/google/android/exoplayer2/source/hls/offline/HlsDownloaderTest.java
@@ -35,7 +35,6 @@ import static com.google.android.exoplayer2.testutil.CacheAsserts.assertCachedDa
 import static com.google.common.truth.Truth.assertThat;
 
 import android.net.Uri;
-import android.support.annotation.Nullable;
 import com.google.android.exoplayer2.offline.DownloaderConstructorHelper;
 import com.google.android.exoplayer2.source.hls.playlist.RenditionKey;
 import com.google.android.exoplayer2.testutil.FakeDataSet;
@@ -44,6 +43,8 @@ import com.google.android.exoplayer2.upstream.cache.NoOpCacheEvictor;
 import com.google.android.exoplayer2.upstream.cache.SimpleCache;
 import com.google.android.exoplayer2.util.Util;
 import java.io.File;
+import java.util.ArrayList;
+import java.util.List;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
@@ -78,7 +79,7 @@ public class HlsDownloaderTest {
   }
 
   @After
-  public void tearDown() throws Exception {
+  public void tearDown() {
     Util.recursiveDelete(tempFolder);
   }
 
@@ -132,7 +133,7 @@ public class HlsDownloaderTest {
         .setRandomData(MEDIA_PLAYLIST_3_DIR + "fileSequence1.ts", 14)
         .setRandomData(MEDIA_PLAYLIST_3_DIR + "fileSequence2.ts", 15);
 
-    HlsDownloader downloader = getHlsDownloader(MASTER_PLAYLIST_URI, null);
+    HlsDownloader downloader = getHlsDownloader(MASTER_PLAYLIST_URI, getKeys());
     downloader.download();
 
     assertCachedData(cache, fakeDataSet);
@@ -152,7 +153,7 @@ public class HlsDownloaderTest {
 
   @Test
   public void testDownloadMediaPlaylist() throws Exception {
-    HlsDownloader downloader = getHlsDownloader(MEDIA_PLAYLIST_1_URI);
+    HlsDownloader downloader = getHlsDownloader(MEDIA_PLAYLIST_1_URI, getKeys());
     downloader.download();
 
     assertCachedData(
@@ -175,21 +176,21 @@ public class HlsDownloaderTest {
             .setRandomData("fileSequence1.ts", 11)
             .setRandomData("fileSequence2.ts", 12);
 
-    HlsDownloader downloader = getHlsDownloader(ENC_MEDIA_PLAYLIST_URI);
+    HlsDownloader downloader = getHlsDownloader(ENC_MEDIA_PLAYLIST_URI, getKeys());
     downloader.download();
     assertCachedData(cache, fakeDataSet);
   }
 
-  private HlsDownloader getHlsDownloader(String mediaPlaylistUri, @Nullable RenditionKey... keys) {
+  private HlsDownloader getHlsDownloader(String mediaPlaylistUri, List<RenditionKey> keys) {
     Factory factory = new Factory(null).setFakeDataSet(fakeDataSet);
     return new HlsDownloader(
         Uri.parse(mediaPlaylistUri), new DownloaderConstructorHelper(cache, factory), keys);
   }
 
-  private static RenditionKey[] getKeys(int... variantIndices) {
-    RenditionKey[] renditionKeys = new RenditionKey[variantIndices.length];
-    for (int i = 0; i < variantIndices.length; i++) {
-      renditionKeys[i] = new RenditionKey(RenditionKey.GROUP_VARIANTS, variantIndices[i]);
+  private static ArrayList<RenditionKey> getKeys(int... variantIndices) {
+    ArrayList<RenditionKey> renditionKeys = new ArrayList<>();
+    for (int variantIndex : variantIndices) {
+      renditionKeys.add(new RenditionKey(RenditionKey.GROUP_VARIANTS, variantIndex));
     }
     return renditionKeys;
   }
diff --git a/library/smoothstreaming/src/main/java/com/google/android/exoplayer2/source/smoothstreaming/offline/SsDownloadAction.java b/library/smoothstreaming/src/main/java/com/google/android/exoplayer2/source/smoothstreaming/offline/SsDownloadAction.java
index 9c90f92938..5623d40c79 100644
--- a/library/smoothstreaming/src/main/java/com/google/android/exoplayer2/source/smoothstreaming/offline/SsDownloadAction.java
+++ b/library/smoothstreaming/src/main/java/com/google/android/exoplayer2/source/smoothstreaming/offline/SsDownloadAction.java
@@ -24,11 +24,12 @@ import com.google.android.exoplayer2.source.smoothstreaming.manifest.TrackKey;
 import java.io.DataInputStream;
 import java.io.DataOutputStream;
 import java.io.IOException;
+import java.util.List;
 
 /** An action to download or remove downloaded SmoothStreaming streams. */
 public final class SsDownloadAction extends SegmentDownloadAction<TrackKey> {
 
-  private static final String TYPE = "SsDownloadAction";
+  private static final String TYPE = "ss";
   private static final int VERSION = 0;
 
   public static final Deserializer DESERIALIZER =
@@ -39,30 +40,28 @@ public final class SsDownloadAction extends SegmentDownloadAction<TrackKey> {
           return new TrackKey(input.readInt(), input.readInt());
         }
 
-        @Override
-        protected TrackKey[] createKeyArray(int keyCount) {
-          return new TrackKey[keyCount];
-        }
-
         @Override
         protected DownloadAction createDownloadAction(
-            boolean isRemoveAction, String data, Uri manifestUri, TrackKey[] keys) {
-          return new SsDownloadAction(isRemoveAction, data, manifestUri, keys);
+            Uri uri, boolean isRemoveAction, String data, List<TrackKey> keys) {
+          return new SsDownloadAction(uri, isRemoveAction, data, keys);
         }
       };
 
   /**
-   * @see SegmentDownloadAction#SegmentDownloadAction(String, int, boolean, String, Uri,
-   *     Comparable[])
+   * @param uri The SmoothStreaming manifest URI.
+   * @param isRemoveAction Whether the data will be removed. If {@code false} it will be downloaded.
+   * @param data Optional custom data for this action.
+   * @param keys Keys of tracks to be downloaded. If empty, all tracks are downloaded. If {@code
+   *     removeAction} is true, {@code keys} must be empty.
    */
   public SsDownloadAction(
-      boolean isRemoveAction, @Nullable String data, Uri manifestUri, TrackKey... keys) {
-    super(TYPE, VERSION, isRemoveAction, data, manifestUri, keys);
+      Uri uri, boolean isRemoveAction, @Nullable String data, List<TrackKey> keys) {
+    super(TYPE, VERSION, uri, isRemoveAction, data, keys);
   }
 
   @Override
   protected SsDownloader createDownloader(DownloaderConstructorHelper constructorHelper) {
-    return new SsDownloader(manifestUri, constructorHelper, keys);
+    return new SsDownloader(uri, constructorHelper, keys);
   }
 
   @Override
diff --git a/library/smoothstreaming/src/main/java/com/google/android/exoplayer2/source/smoothstreaming/offline/SsDownloader.java b/library/smoothstreaming/src/main/java/com/google/android/exoplayer2/source/smoothstreaming/offline/SsDownloader.java
index c23c50e296..69f6f9e7cf 100644
--- a/library/smoothstreaming/src/main/java/com/google/android/exoplayer2/source/smoothstreaming/offline/SsDownloader.java
+++ b/library/smoothstreaming/src/main/java/com/google/android/exoplayer2/source/smoothstreaming/offline/SsDownloader.java
@@ -42,8 +42,11 @@ import java.util.List;
  * DownloaderConstructorHelper constructorHelper =
  *     new DownloaderConstructorHelper(cache, factory);
  * // Create a downloader for the first track of the first stream element.
- * SsDownloader ssDownloader = new SsDownloader(
- *     manifestUrl, constructorHelper, new TrackKey[] {new TrackKey(0, 0)});
+ * SsDownloader ssDownloader =
+ *     new SsDownloader(
+ *         manifestUrl,
+ *         constructorHelper,
+ *         Collections.singletonList(new TrackKey(0, 0)));
  * // Perform the download.
  * ssDownloader.download();
  * // Access downloaded data using CacheDataSource
@@ -53,9 +56,9 @@ import java.util.List;
  */
 public final class SsDownloader extends SegmentDownloader<SsManifest, TrackKey> {
 
-  /** @see SegmentDownloader#SegmentDownloader(Uri, DownloaderConstructorHelper, Object[]) */
+  /** @see SegmentDownloader#SegmentDownloader(Uri, DownloaderConstructorHelper, List) */
   public SsDownloader(
-      Uri manifestUri, DownloaderConstructorHelper constructorHelper, TrackKey[] trackKeys) {
+      Uri manifestUri, DownloaderConstructorHelper constructorHelper, List<TrackKey> trackKeys) {
     super(SsUtil.fixManifestUri(manifestUri), constructorHelper, trackKeys);
   }
 
@@ -69,7 +72,7 @@ public final class SsDownloader extends SegmentDownloader<SsManifest, TrackKey>
 
   @Override
   protected List<Segment> getSegments(
-      DataSource dataSource, SsManifest manifest, boolean allowIncompleteList) throws IOException {
+      DataSource dataSource, SsManifest manifest, boolean allowIncompleteList) {
     ArrayList<Segment> segments = new ArrayList<>();
     for (StreamElement streamElement : manifest.streamElements) {
       for (int i = 0; i < streamElement.formats.length; i++) {
diff --git a/playbacktests/src/androidTest/java/com/google/android/exoplayer2/playbacktests/gts/DashDownloadTest.java b/playbacktests/src/androidTest/java/com/google/android/exoplayer2/playbacktests/gts/DashDownloadTest.java
index 5bf962a3b4..c5ac2131f3 100644
--- a/playbacktests/src/androidTest/java/com/google/android/exoplayer2/playbacktests/gts/DashDownloadTest.java
+++ b/playbacktests/src/androidTest/java/com/google/android/exoplayer2/playbacktests/gts/DashDownloadTest.java
@@ -123,8 +123,7 @@ public final class DashDownloadTest extends ActivityInstrumentationTestCase2<Hos
     }
     DownloaderConstructorHelper constructorHelper =
         new DownloaderConstructorHelper(cache, httpDataSourceFactory);
-    return new DashDownloader(
-        MANIFEST_URI, constructorHelper, keys.toArray(new RepresentationKey[keys.size()]));
+    return new DashDownloader(MANIFEST_URI, constructorHelper, keys);
   }
 
 }