com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
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 reasons, such as:
- The MySQL server is not running.
- The MySQL server is not listening on the correct port.
- The MySQL server is not accessible due to a firewall or network issue.
- The MySQL client library is not properly installed or configured.
To troubleshoot this issue, you can try the following:
- Make sure that the MySQL server is running and that you can connect to it using the MySQL command line client or a GUI tool like MySQL Workbench.
- Check the MySQL server logs for any error messages that might help diagnose the issue.
- Make sure that the MySQL server is listening on the correct port and that it is accessible from the machine where your Java program is running.
- Make sure that the MySQL client library (e.g.,
mysql-connector-java) is properly installed and configured.
I hope this helps! Let me know if you have any questions.