@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