import com.google.api.services.drive.model.ChangeList; //导入依赖的package包/类
/**
 * Gets the drive changes info in the My Tracks folder, including deleted
 * files.
 * 
 * @param changeId the largest change id
 * @param changes a map of drive id to file for the changes
 * @return an updated largest change id
 */
private long getDriveChangesInfo(long changeId, Map<String, File> changes) throws IOException {
  Changes.List request = drive.changes().list().setStartChangeId(changeId + 1);
  do {
    ChangeList changeList = request.execute();
    long newId = changeList.getLargestChangeId().longValue();

    for (Change change : changeList.getItems()) {
      if (change.getDeleted()) {
        changes.put(change.getFileId(), null);
      } else {
        File file = change.getFile();
        if (file.getLabels().getTrashed()) {
          changes.put(change.getFileId(), null);
        } else {
          changes.put(change.getFileId(), file);
        }
      }
    }
    if (newId > changeId) {
      changeId = newId;
    }
    request.setPageToken(changeList.getNextPageToken());
  } while (request.getPageToken() != null && request.getPageToken().length() > 0);
  Log.d(TAG, "Got drive changes: " + changes.size() + " " + changeId);
  return changeId;
}
 

import com.google.api.services.drive.model.ChangeList; //导入依赖的package包/类
public List<Change> getChanges(Long startChangeId) throws IOException {
	List<Change> changes = new ArrayList<Change>();
	Changes.List request = drive.changes().list();
	if (startChangeId != null) {
		request.setStartChangeId(startChangeId);
	}
	do {
		ChangeList changeList = request.execute();
		changes.addAll(changeList.getItems());
		request.setPageToken(changeList.getNextPageToken());
	} while (request.getPageToken() != null && request.getPageToken().length() > 0);
	return changes;
}
 

import com.google.api.services.drive.model.ChangeList; //导入依赖的package包/类
public List<String> getNewDiffs() throws Exception {
    getDeviceFolderId(true); // required
    Log.d(TAG, "Looking for updates in the device folder...");
    List<String> result = new ArrayList<String>();
    long lcid = session.driveLastChangeID();
    ChangeList changes;
    File file;
    Changes.List request = service.changes().list().setIncludeDeleted(false).setIncludeSubscribed(
        false).setFields("items/file,largestChangeId,nextPageToken").setStartChangeId(lcid + 1);
    do {
        try {
            changes = request.execute();
            for (Change change: changes.getItems()) {
                file = change.getFile();
                if (!file.getTitle().endsWith(".diff"))
                    continue;
                // check for deleted (looks like List.setIncludeDeleted(false) has no effects)
                Boolean deleted = change.getDeleted();
                if (deleted != null && deleted)
                    continue;
                deleted = file.getExplicitlyTrashed();
                if (deleted != null && deleted)
                    continue;
                for (ParentReference parent: file.getParents())
                    if (parent.getId().equals(deviceId)) {
                        result.add(file.getId());
                        break;
                    }
            }
            lcid = changes.getLargestChangeId();
            request.setPageToken(changes.getNextPageToken());
        } catch (Exception err) {
            Log.e(TAG, "getNewDiffs", err);
            request.setPageToken(null);
        }
    } while (request.getPageToken() != null && request.getPageToken().length() > 0);
    session.setDriveLastChangeID(lcid);
    Log.i(TAG, "Found " + Integer.toString(result.size()) + " diffs since last check.");
    return result;
}
 

import com.google.api.services.drive.model.ChangeList; //导入依赖的package包/类
public Changes(ChangeList changes) {
    largestChangeId = changes.getLargestChangeId();
    items = Lists.transform(changes.getItems(), new Function<com.google.api.services.drive.model.Change, Change>() {
        @Override
        public Change apply(com.google.api.services.drive.model.Change change) {
            return new Change(change);
        }
    });
}
 

import com.google.api.services.drive.model.ChangeList; //导入依赖的package包/类
public Long getLargestChangeId() throws IOException {
	Changes.List request = drive.changes().list();
	request.setMaxResults(1);
	ChangeList changeList = request.execute();
	return changeList.getLargestChangeId();		
}