It’s a good idea to use an abstract class when you need to implement mutable state. As an example, the Java Collections Framework includes the AbstractList class, which uses the state of variables.

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 ...

(See Effective Java, "Prefer interfaces to abstract classes ... or as the base type for an anonymous class. 1 This example uses a form of switch expression -- one that uses patterns as case ...

For this Java Function interface example, we will provide a single method named ... as is the case with object models designed with abstract classes and interfaces. Power through simplicity is exactly ...