@Tencent KJAVAWEB后台编写中，web程序与mysql数据库连接时遇到的问题
**org.apache.ibatis.exceptions.PersistenceException:

Error querying database. Cause: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.

The error may exist in com/hrbeu/mapper/AccountMapper.xml

The error may involve com.hrbeu.mapper.AccountMapper.selByAccnoPwd

The error occurred while executing a query

Cause: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure**

经过各种排查

			<property name="url" value="jdbc:mysql://localhost:306/managesystem"/>

url中端口号写错