I have a JList in a ScrollPane and i'd like to be able to return the index value of the list when the enter key is pressed. I am trying to understand the overall concept of listeners, but i'm ...

For more information about this topic, read the How to Write a Mouse Listener lesson of The Java Tutorial. Adapters aren’t limited to mouse listening.

The Observable design pattern is found in many Java APIs and in reactive programming. Here's an introduction to the timeless Observable pattern in Java.