先接收离线消息后再通知openfire上线
//获取离线消息 OfflineMessageManager offlineMessageManager=new OfflineMessageManager(connection); Iterator<Message> messages=offlineMessageManager.getMessages(); while (messages.hasNext()){ Message msg=messages.next(); System.out.println(msg.toXML()); }
原文：https://www.cnblogs.com/tiancai/p/10072679.html