How-to articles, tricks, and solutions about JDBC
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure is an exception that is thrown when there is a failure in the communication link between your Java program and the MySQL database. This can happen for a variety of reason
To find out your MySQL connection details, you will need to look in your MySQL configuration files. The specific location of these files will depend on how you installed MySQL, but common locations include /etc/my.cnf,
A java.sql.SQLException: Access denied for user 'root'@'localhost' (using password: YES) error typically indicates that the MySQL server is unable to authenticate the user with the provided username and password.