java.sql.SQLException: The server time zone value 'xxx' is unrecognized or represents more than one
java.sql.SQLException: The server time zone value 'xxx' is unrecognized or represents more than one time zone.
时区不对，因为mysql-connection-java版本导致时区的问题。
解决方式：
不加版本号或者版本号为6以上，解决方式：在连接数据库的配置文件中加上以下，时区亚洲/上海，添加代码&serverTimezone=Asia/Shanghai
如下：jdbc:mysql://localhost:3306/renren_fast?useUnicode=true&characterEncoding=UTF-8&serverTimezone=Asia/Shanghai