在IDEA中使用JDBC获取数据库连接时,有时会报错Sat Dec 19 19:32:18 CST 2020 WARN: 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.
解决办法：
在DriverManager.getConnection()方法的第一次参数的"数据库名称"后加上下方黑体标注内容“？useSSL=false”.
conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/userlogin?useSSL=false","****","******");