Create packages, import packaged classes and interfaces into your programs, move packages, and encapsulate them in jar files.

The Java Tutorial goes on to list bullets for when an abstract class should be considered and for when an interface should be considered. Unsurprisingly, these are derived from the previously ...

Okay, so you have an interface Monitor.How would you name classes that monitor Files and Bird Movement? How about in general?Since we have had a few style question recently, it came to mind.

Sealed classes in Java let developers limit the creation and use of subclasses and preserve the class hierarchy. Here is how sealed classes in Java work.