The difference between abstract classes and interfaces has long vexed Java developers. Find out how Java 8's default methods introduce both new complexity and new options to that familiar ...

An abstract class can declare fields, constructors, and non-abstract methods in addition to or instead of abstract methods. For example, an abstract Vehicle class might declare fields describing ...

There is a reason why Java method modifiers exist. If you call public methods internally and don't understand why, your developers could face major class issues.