Twain device (scanner) control in Java

I want to scan a number of papers through Java. I found the mm's computing twain library.

When I run the example TwainExample.java at the site, I receive this error.

uk.co.mmscomputing.device.twain.TwainIOException: Cannot load Twain Source Manager.

On the other hand, almost the same code works with ImageJ as a plugin. Yet, when I used this code by itself I still receive the same exception.

I wonder why this is not working.