When you execute the Java code with the MySQL database connectivity in your machine or server and sometimes you may get an error as below,

Tue Feb 19 19:15:14 IST 2019 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 verifyServerCertifica 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.

Turning on the SSL=true with the database connectivity like below,
con = DriverManager.getConnection("jdbc:mysql://localhost:3306/DB_NAME?verifyServerCertificate=false&useSSL=true","dbuser","password");

or if you would like to turning off SSL server verification,
con = DriverManager.getConnection("jdbc:mysql://localhost:3306/DB_NAME?autoReconnect=true&useSSL=false","dbuser","password");