Classes, fields, methods, constructors, and objects are the building blocks of object-based Java applications. This Java tutorial teaches you how to declare classes, describe attributes via fields ...

Java uses empty interfaces to tag, that is, mark object classes that are to be singled out for special treatment. Empty interface examples include Cloneable, Serializable, and UIResource.

However, the Java Platform provides a data structure that greatly simplifies the use of reference objects like this, called the java.util.WeakHashMap class. WeakHashMap works exactly like a hash ...