What is the purpose of a listener in Java?

Question

I looked for this online, but couldn\'t find an adequate explanation to what it exactly does. What I saw was a Java Interface and it was passed as a parameter in another cla

Answer 1

Listeners are used for notify about state changes. You can think about Listeners in most of time as Observers, so every time something interesting happen your listener will be called.

You can read more about patterns in Java on following websites:

http://www.journaldev.com/1739/observer-design-pattern-in-java-example-tutorial

http://www.developer.com/java/implementing-behavioral-patterns-in-java.html