Caused by: com.mysql.cj.exceptions.CJCommunicationsException: Communications link failure The last packet successfully received from the server was 0 milliseconds ago. The last packet sent successfully to the server was 0 milliseconds ago.二 解决方法
看了一位老哥的办法，直接秒解决。
jdbc:mysql://111.111.111.111:3306/yyds?useUnicode=true&characterEncoding=UTF-8&serverTimezone=UTC后面加上&useSSL=false，
即jdbc:mysql://111.111.111.111:3306/yyds?useUnicode=true&characterEncoding=UTF-8&serverTimezone=UTC&useSSL=false
