异常错误：Communications link failure The last packet successfully received from the server was 3,544 milliseconds ago
解决方法：
找到application-druid.yml文件
将testOnBorrow: false
修改为
testOnBorrow: true
连接mysql报错：Communications link failure The last packet successfully received from the server was 3,544 milliseconds ago
原文：https://www.cnblogs.com/object360/p/13391412.html
