Abstract classes and interfaces in Java serve fundamentally ... class when you need to implement mutable state. As an example, the Java Collections Framework includes the AbstractList class ...

If you’ve read my Java 101 tutorial ... or you might abstract these details into a common superclass. Alternatively, you could leverage Listing 1’s Addressable interface.

For this Java Function interface example, we will provide a single method named ... a method that takes something and returns something else seems to be so incredibly vague and abstract that is almost ...

Interfaces, however, support multiple inheritances where abstract classes don't. Implementation is done similarly in Java. For example, using the keyword implements will make a Java interface, while ...