Failed to obtain JDBC Connection; nested exception is 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.
Caused by: java.sql.SQLException: The server time zone value=问题解决，由于使用了新版mysql等数据库
解决：在jdbc连接的url后面添加serverTimezone=CST
例如：
jdbc:mysql://localhost:3306/demo改为
jdbc:mysql://localhost:3306/demo?serverTimezone=CST
原因：使用mysql的jdbc驱动最新版（6.0+）时，会遇到数据库和系统时区差异引起的问题。
注：CST代表的是中国上海时间（与北京时间，东八区相同）。
改后：
spring:
datasource:
driver-class-name: com.mysql.cj.jdbc.Driver
username: root
password: 1234
url: jdbc:mysql://localhost:3306/mydatabase?serverTimezone=CST&useUnicode=true&characterEncoding=UTF-8&zeroDateTimeBehavior=convertToNull&useSSL=true