What is the difference between listeners and adapters?

Question

I\'m trying to differentiate between listeners and adapters.

Are they pretty much the same but in listeners you have to implement all the methods in the interface, but w

Answer 1

There is another aspect which is not addressed in other answers: API evolution. Providing adapter classes (a.k.a empty or default implementations of interfaces) makes introducing new methods in interfaces less painful. If an API provides only interfaces then clients are forced to implement them and if a new method is added to the interfaces then all implementing classes will break. However, if default implementations are provided then clients have the chance to extend those instead which, apart from being convenient, helps them upgrading to newer API version. With default methods of Java 8 default/empty implementation have become less important but they might be handy in older versions.