局域网即时聊天系统，C/S模式；java TCP Socket；多线程程序设计；java图形界面设计；私聊；群聊；更新用户列表；上、下线提醒；脏话过滤-LAN instant messaging system, C/S mode java TCP Socket multi-threaded programming java graphical user interface design whisper group chat update the user list on the a