实现功能：(1)客户端开机自动琐定，输入帐号、密码后进行验证登陆并开始计费。或控制端远程解锁上机。 (2).控制端能够对上网的客户端进行远程控制，比如：远程关机、注销、锁定、远程结帐后又自动锁定计算机等功能。 (3）能对客户端发送消息。 (4）客户端在上机过程中能够随时查看消费状态，比如：预缴金额、上机时间、上机金额等。 MySql表结构： desc user; +----------+-------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +----------+-------------+------+-----+---------+-------+ | uid | varchar(30) | NO | PRI | 0 | | | password | varchar(30) | NO | | 0 | | | balance | double | NO | | 0 | | | isvip | int(2) | NO | | 0 | | +----------+-------------+------+-----+---------+-------+ 4 rows in set (0.00 sec) desc userhistory; +-----------+-------------+------+-----+-------------------+-------+ | Field | Type | Null | Key | Default | Extra | +-----------+-------------+------+-----+-------------------+-------+ | cid | varchar(30) | NO | | 0 | | | uid | varchar(30) | NO | MUL | 0 | | | isvip | int(2) | NO | | 0 | | | logintime | timestamp | NO | | CURRENT_TIMESTAMP | | | usetime | varchar(30) | NO | | 00:00:00 | | | cost | double | NO | | 0 | | +-----------+-------------+------+-----+-------------------+-------+ 6 rows in set (0.00 sec) 涉及知识点：swing，socket和serverSocket，jdbc，多线程，心跳包建立长连接，通信消息封装为xml。。。。