在ubuntu中运行的后台报错，就是数据库连接问题，但不知道是程序问题还是虚拟机没连上windows的mysql：
primary - Exception during pool initialization.
com.mysql.cj.jdbc.exceptions.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.
windows中mysql用的账号不是root，是自定义的账号，账号的主机是%,不是localhost，所以远程应该也开了，怎么测试linux是不是连接到了windows的mysql呢？我不知道现在后台连不上是因为程序问题还是单纯的没连上mysql
