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/goods/BrandMapper.java (best guess)

The error may involve com.goods.dao.BrandMapper.selectAll

The error occurred while executing a query

Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Failed to obtain JDBC Connection; nested exception is 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.] with root cause

在如上报错，调试后的经验，希望对各位有帮助：

useSSL=false