import com.google.samples.apps.iosched.sync.userdata.AbstractUserDataSyncHelper; //导入依赖的package包/类
@Override
public void run(final Context context, final Callback callback) {
    new AsyncTask<Context, Void, Void>() {
        @Override
        protected Void doInBackground(Context... params) {
            final AbstractUserDataSyncHelper syncer = UserDataSyncHelperFactory.buildSyncHelper(
                    context, AccountUtils.getActiveAccountName(context));
            syncer.sync();
            return null;
        }

        @Override
        protected void onPostExecute(Void aVoid) {
            callback.done(true, "Sync done");
        }
    }.execute(context);

}
 

import com.google.samples.apps.iosched.sync.userdata.AbstractUserDataSyncHelper; //导入依赖的package包/类
/**
 * Checks if there are changes on User's Data to sync with/from remote AppData folder.
 *
 * @return Whether or not data was changed.
 * @throws IOException if there is a problem uploading the data.
 */
private boolean doUserDataSync(String accountName) throws IOException {
    if (!isOnline()) {
        LOGD(TAG, "Not attempting userdata sync because device is OFFLINE");
        return false;
    }

    LOGD(TAG, "Starting user data sync.");

    AbstractUserDataSyncHelper helper = UserDataSyncHelperFactory.buildSyncHelper(
            mContext, accountName);
    boolean modified = helper.sync();
    if (modified) {
        // Schedule notifications for the starred sessions.
        Intent scheduleIntent = new Intent(
                SessionAlarmService.ACTION_SCHEDULE_ALL_STARRED_BLOCKS,
                null, mContext, SessionAlarmService.class);
        mContext.startService(scheduleIntent);
    }
    return modified;
}
 

import com.google.samples.apps.iosched.sync.userdata.AbstractUserDataSyncHelper; //导入依赖的package包/类
/**
 * Checks if there are changes on MySchedule to sync with/from remote AppData folder.
 *
 * @return Whether or not data was changed.
 * @throws IOException if there is a problem uploading the data.
 */
private boolean doUserScheduleSync(String accountName) throws IOException {
    if (!isOnline()) {
        LOGD(TAG, "Not attempting myschedule sync because device is OFFLINE");
        return false;
    }

    LOGD(TAG, "Starting user data (myschedule) sync.");

    AbstractUserDataSyncHelper helper = UserDataSyncHelperFactory.buildSyncHelper(
            mContext, accountName);
    boolean modified = helper.sync();
    if (modified) {
        // schedule notifications for the starred sessions
        Intent scheduleIntent = new Intent(
                SessionAlarmService.ACTION_SCHEDULE_ALL_STARRED_BLOCKS,
                null, mContext, SessionAlarmService.class);
        mContext.startService(scheduleIntent);
    }
    return modified;
}
 

import com.google.samples.apps.iosched.sync.userdata.AbstractUserDataSyncHelper; //导入依赖的package包/类
/**
 * Checks if there are changes on User's Data to sync with/from remote AppData folder.
 *
 * @return Whether or not data was changed.
 * @throws IOException if there is a problem uploading the data.
 */
private boolean doUserDataSync(SyncResult syncResult) throws IOException {
    if (!ConnectivityUtils.isConnected(mContext)) {
        LOGD(TAG, "Not attempting userdata sync because device is OFFLINE");
        return false;
    }

    String accountName = AccountUtils.getActiveAccountName(mContext);
    if (TextUtils.isEmpty(accountName)) {
        LOGD(TAG, "Not attempting userdata sync because user is not signed in");
        return false;
    }

    LOGD(TAG, "Starting user data sync.");

    AbstractUserDataSyncHelper helper = UserDataSyncHelperFactory.buildSyncHelper(
            mContext, accountName);
    boolean modified = helper.sync();

    if (modified) {
        // Schedule notifications for the starred sessions.
        Intent scheduleIntent = new Intent(
                SessionAlarmService.ACTION_SCHEDULE_ALL_STARRED_BLOCKS,
                null, mContext, SessionAlarmService.class);
        mContext.startService(scheduleIntent);
    }
    syncResult.stats.numIoExceptions += helper.getIoExcpetions();
    return modified;
}