报错误信息
org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (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.)
原因：本地测试连接的mysql数据库版本5.7,生产上用的还是老版本的mysql 5.6，包冲突了
解决：
pom.xml
mysql mysql-connector-java 5.1.9
改成5.1.40
