This error message may include the following text also:
“The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.”
When we try to connect to a MySQL server “Communications link failure” error may occur for any of the following errors:
- MySQL server is not running. Check for this and run the sever if it is stopped.
- Host name is wrong: If the server is running in the same computer, the correct host name is localhost otherwise it is a valid IP address or computer name.
- Wrong port no given : By default MySQL server runs in port 3306. If it is different, check that correct port no is given.
Sumber : http://java-error-messages.blogspot.com/2011/04/commysqljdbcexceptionsjdbc4communicatio.html