Sat May 15 20:00:19 CST 2021 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.
看到这里我们需要特别注意下最后一句话：
You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
意思是：
您需要通过设置useSSL=false显式禁用SSL，或者设置useSSL=true并为服务器证书验证提供信任库。
这时我们只需要在连接数据库的url上设置：useSSL=false就可以了。
值得注意的是当usessl设置为true的时候，虽然项目可以运行，但是会发现执行的速度慢了很多，这个原因不明白，这里记录一下，以后深究。
