JDBC Configuration Errors

You might get errors while configuring a JDBC connection. If you are using MySQL, and the connection URL is incorrect, or the MySQL database is not running, the following error message is generated:

Communications link failure 

If you are using Oracle database, some possible connection configuration errors are listed below:

IO exception: The Network Adapter could not establish the connection IO exception: Connection refused 

The The Network Adapter could not establish the connection exception is caused by one or more of the following configuration errors:

The Connection refused exception is caused by one or more of the following configuration errors:

At the SQL prompt, start the database instance with the startup command.

SQL>startup