Abstract classes and interfaces are plentiful in Java code, and even in the Java Development Kit (JDK) itself. Each code element serves a fundamental purpose: Many developers believe that ...

This protects code from being used incorrectly. Abstract classes require subclasses to further define ... For example, using the keyword implements will make a Java interface, while the keyword ...

There are times when you need to associate metadata, or data that describes data, with classes, methods, or other elements in your Java code ... Using @interface to declare annotation types ...

So a more concise lambda expression that implements this Java Function interface would look like this: When the code implements Java Function ... as is the case with object models designed with ...