public void syncLocalToDropbox(DbxClient client) throws DbxException, IOException {
logger.debug("Started synchronization from local to Dropbox ...");
Map<String, Long> dropboxEntries = new HashMap<String, Long>();
WithChildren metadata = client.getMetadataWithChildren("/");
File dropboxEntryFile = new File(contentDir + DROPBOX_ENTRIES_FILE_NAME);
if (!dropboxEntryFile.exists() || !metadata.hash.equals(lastHash)) {
collectDropboxEntries(client, dropboxEntries, "/");
serializeDropboxEntries(dropboxEntryFile, dropboxEntries);
lastHash = metadata.hash;