java连接mysql数据库的时候，提示：
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
解决方法：
（1）
检查url地址是否正确,ip地址要写成127.0.0.1或者写成localhost，端口号为3306。
（2）
修改mysql的配置参数
$sudo vim /etc/mysql/my.cnf
添加以下内容
[mysqld]
wait_timeout=31536000
intercative_timeout=31536000
(3)重启mysql
$service mysql restart
