java.sql.SQLException: The server time zone value ‘�й���׼ʱ��’ is 
unrecognized or represents more than one time zone. You must configure either 
the server or JDBC driver (via the serverTimezone configuration property) to use 
a more specifc time zone value if you want to utilize time zone support.

SpringBoot在连接数据库的时候会出现这种情况，大家不必惊慌，只需修改一下代码就行。
解决方法：
在URL上加上：?serverTimezone=GMT%2B8&useUnicode=true&characterEncoding=utf-8