public void sendNotifcationToTags( String apiKey, String tag, String title, String message, String uri, boolean save) { Set<String> usernameSet = sessionManager.getUsernameSet(tag); if (usernameSet == null) { return; } Iterator<String> iterator = usernameSet.iterator(); while (iterator.hasNext()) { String username = (String) iterator.next(); System.out.println("sendNotifcationToTags--username:" + username); sendNotifcationToUser(apiKey, username, title, message, uri, save); } }