jdbc连接mysql出现以下警告：
Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
解决方法：
url后面加上 useSSL=false
举个栗子↓
jdbc:mysql://localhost:3306/test?useSSL=false如果还有别的设置（例如时区、字符集啥的，可以用"&"符号连接），举个栗子↓
jdbc:mysql://localhost/test?serverTimezone=UTC&useUnicode=true&characterEncoding=utf8&useSSL=false但如果在xml文件中就不能直接用"&"符号连接了，应该用"&"，举个栗子↓
jdbc:mysql://localhost/test?serverTimezone=UTC&useUnicode=true&characterEncoding=utf8&useSSL=false