Load HCL Informix® JDBC Driver

try 
    {
    Class.forName("com.informix.jdbc.IfxDriver");
    } 
catch (Exception e)
    {
    System.out.println("ERROR: failed to load Informix JDBC driver.");
    e.printStackTrace();
    return;
    }

The Class.forName() method loads the Informix® implementation of the Driver class, IfxDriver. IfxDriver then creates an instance of the driver and registers it with the DriverManager class.

After you have loaded Informix® JDBC Driver, you are ready to connect to the Informix® database or database server.

If you are writing an applet to be viewed with Microsoft™ Internet Explorer, you might need to explicitly register Informix® JDBC Driver to avoid platform incompatibilities.

DriverManager.registerDriver(com.informix.jdbc.IfxDriver) 
   Class.forName("com.informix.jdbc.IfxDriver").newInstance());

This method might register Informix® JDBC Driver twice, which does not cause a problem.