import com.google.samples.apps.iosched.provider.ScheduleContract.Announcements; //导入依赖的package包/类
public ArrayList<ContentProviderOperation> fetchAndParse() throws IOException {
    final ArrayList<ContentProviderOperation> batch = Lists.newArrayList();

    // Set up the HTTP transport and JSON factory
    HttpTransport httpTransport = new NetHttpTransport();
    JsonFactory jsonFactory = new AndroidJsonFactory();

    // Set up the main Google+ class
    Plus plus = new Plus.Builder(httpTransport, jsonFactory, null)
            .setApplicationName(NetUtils.getUserAgent(mContext))
            .setGoogleClientRequestInitializer(
                    new CommonGoogleClientRequestInitializer(Config.API_KEY))
            .build();

    ActivityFeed activities;
    try {
        activities = plus.activities().list(Config.ANNOUNCEMENTS_PLUS_ID, "public")
                .setMaxResults(100l)
                .execute();
        if (activities == null || activities.getItems() == null) {
            throw new IOException("Activities list was null.");
        }

    } catch (IOException e) {
        LOGE(TAG, "Error fetching announcements", e);
        return batch;
    }

    LOGI(TAG, "Updating announcements data");

    // Clear out existing announcements
    batch.add(ContentProviderOperation
            .newDelete(ScheduleContract.addCallerIsSyncAdapterParameter(
                    Announcements.CONTENT_URI))
            .build());

    StringBuilder sb = new StringBuilder();
    for (Activity activity : activities.getItems()) {
        // Filter out anything not including the conference hashtag.
        sb.setLength(0);
        appendIfNotEmpty(sb, activity.getAnnotation());
        if (activity.getObject() != null) {
            appendIfNotEmpty(sb, activity.getObject().getContent());
        }

        if (!sb.toString().contains(Config.CONFERENCE_HASHTAG)) {
            continue;
        }

        // Insert announcement info
        batch.add(ContentProviderOperation
                .newInsert(ScheduleContract
                        .addCallerIsSyncAdapterParameter(Announcements.CONTENT_URI))
                .withValue(SyncColumns.UPDATED, System.currentTimeMillis())
                .withValue(Announcements.ANNOUNCEMENT_ID, activity.getId())
                .withValue(Announcements.ANNOUNCEMENT_DATE, activity.getUpdated().getValue())
                .withValue(Announcements.ANNOUNCEMENT_TITLE, activity.getTitle())
                .withValue(Announcements.ANNOUNCEMENT_ACTIVITY_JSON, activity.toPrettyString())
                .withValue(Announcements.ANNOUNCEMENT_URL, activity.getUrl())
                .build());
    }

    return batch;
}