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 has been very active lately in improving its concurrency model, and some of the improvements are inspired by Kotlin’s coroutines. Coroutines give you a different kind of access to threading.

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