import com.google.api.services.youtube.model.PlaylistListResponse; //导入依赖的package包/类
@Override
protected PlaylistListResponse doInBackground(String[]... params) {

    final String[] playlistIds = params[0];

    PlaylistListResponse playlistListResponse;
    try {
        playlistListResponse = mYouTubeDataApi.playlists()
            .list(YOUTUBE_PLAYLIST_PART)
            .setId(TextUtils.join(",", playlistIds))
            .setFields(YOUTUBE_PLAYLIST_FIELDS)
            .setKey(ApiKey.YOUTUBE_API_KEY)
            .execute();
    } catch (IOException e) {
        e.printStackTrace();
        return null;
    }
     
    return playlistListResponse;
}
 

import com.google.api.services.youtube.model.PlaylistListResponse; //导入依赖的package包/类
private String nextToken() {
  String result = null;

  if (response == null)
    result = ""; // first time
  else {
    // is there a better way of doing this?
    if (response instanceof SearchListResponse) {
      result = ((SearchListResponse) response).getNextPageToken();
    } else if (response instanceof PlaylistItemListResponse) {
      result = ((PlaylistItemListResponse) response).getNextPageToken();
    } else if (response instanceof SubscriptionListResponse) {
      result = ((SubscriptionListResponse) response).getNextPageToken();
    } else if (response instanceof VideoListResponse) {
      result = ((VideoListResponse) response).getNextPageToken();
    } else if (response instanceof PlaylistListResponse) {
      result = ((PlaylistListResponse) response).getNextPageToken();
    } else {
      doHandleExceptionMessage("nextToken bug!");
    }
  }

  return result;
}
 

import com.google.api.services.youtube.model.PlaylistListResponse; //导入依赖的package包/类
/** {@inheritDoc} */
@Override
    public List<Playlist> getNext() throws IOException {
        final List <Playlist> playlists = new ArrayList<>();

        _playlistReq.setPageToken(_nextToken);
        PlaylistListResponse playlistListResponse = _playlistReq.execute();
        playlists.addAll(playlistListResponse.getItems());
        _nextToken = playlistListResponse.getNextPageToken();

        return playlists;
    }
 

import com.google.api.services.youtube.model.PlaylistListResponse; //导入依赖的package包/类
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setRetainInstance(true);
    if (getArguments() != null) {
        mPlaylistIds = getArguments().getStringArray(ARG_YOUTUBE_PLAYLIST_IDS);
    }

    // start fetching the playlist titles
    new GetPlaylistTitlesAsyncTask(mYouTubeDataApi) {
        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            mProgressDialog.show();
        }
        
        @Override
        protected void onPostExecute(PlaylistListResponse playlistListResponse) {
            // if we didn't receive a response for the playlist titles, then there's nothing to update
            if (playlistListResponse == null)
                return;

            mPlaylistTitles = new ArrayList();
            for (com.google.api.services.youtube.model.Playlist playlist : playlistListResponse.getItems()) {
                mPlaylistTitles.add(playlist.getSnippet().getTitle());
            }
            // update the spinner adapter with the titles of the playlists
            ArrayAdapter<List<String>> spinnerAdapter = new ArrayAdapter(getContext(), android.R.layout.simple_spinner_item, mPlaylistTitles);
            spinnerAdapter.setDropDownViewResource(SPINNER_ITEM_DROPDOWN_LAYOUT_ID);
            mPlaylistSpinner.setAdapter(spinnerAdapter);
            mProgressDialog.hide();
        }
    }.execute(mPlaylistIds);
}
 

import com.google.api.services.youtube.model.PlaylistListResponse; //导入依赖的package包/类
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setRetainInstance(true);

    mYouTubeDataApi = new YouTube.Builder(mTransport, mJsonFactory, null)
            .setApplicationName(getResources().getString(R.string.app_name))
            .build();

    mInterstitialAd = new InterstitialAd(mActivity);
    mInterstitialAd.setAdUnitId(getString(R.string.interstitial_ad_unit_id));

    mInterstitialAd.loadAd(new AdRequest.Builder().addTestDevice("121EC3F83A2EAFBD46DB00F1773A13A0").build());
    mInterstitialAd.setAdListener(new AdListener() {
        @Override
        public void onAdClosed() {
            // Load the next interstitial.
            mInterstitialAd.loadAd(new AdRequest.Builder().addTestDevice("121EC3F83A2EAFBD46DB00F1773A13A0").build());
        }

    });

    if (getArguments() != null) {
        mPlaylistIds = getArguments().getStringArray(ARG_PLAYLIST_IDS);
    }

    // start fetching the playlist titles
    new GetPlaylistTitlesAsyncTask(mYouTubeDataApi) {
        @Override
        protected void onPostExecute(PlaylistListResponse playlistListResponse) {
            // if we didn't receive a response for the playlist titles, then there's nothing to update
            if (playlistListResponse == null)
                return;

            mPlaylistTitles = new ArrayList();
            for (com.google.api.services.youtube.model.Playlist playlist : playlistListResponse.getItems()) {
                mPlaylistTitles.add(playlist.getSnippet().getTitle());
            }
            // update the spinner adapter with the titles of the playlists
            if(mActivity==null){
                return;
            }
            ArrayAdapter<List<String>> spinnerAdapter = new ArrayAdapter(mActivity, android.R.layout.simple_spinner_item, mPlaylistTitles);
            spinnerAdapter.setDropDownViewResource(SPINNER_ITEM_DROPDOWN_LAYOUT_ID);
            mPlaylistSpinner.setAdapter(spinnerAdapter);
        }
    }.execute(mPlaylistIds);
}