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, ...

Object-oriented systems are usually partitioned into layers of related responsibilities and only dependencies in one direction are allowed, from higher layers (more specific, less reusable) to lower ...

Persistence is one of the greatest challenges for building applications. There are many options for building persistence layers. Data Access Objects (DAO) is a popular design pattern for building the ...

Method references are a shorthand way to write lambda expressions that call a single method. Rather than implementing a method in a functional interface, a method reference simply points to an ...