“com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failureLast packet sent to the server was 0 ms ago.” 解决方式:
上述问题是由mysql5数据库的配置引起的。mysql5将其连接的等待时间(wait_timeout)缺省为8小时。在其客户程序中可以这样来查看其值:
mysql﹥ show global variables like 'wait_timeout';
+---------------+---------+
| Variable_name | Value |
+---------------+---------+
| wait_timeout | 28800 |
+---------------+---------+
1 row in set (0.00 sec)
28800 seconds,也就是8小时。