Classes and objects in Java must be initialized before they are used. You’ve previously learned that class fields are initialized to default values when classes are loaded, and that objects are ...

The Jakarta Persistence API (JPA) is a specification that defines a standardized framework for data persistence. Persistence is the fundamental mechanism for saving and retrieving data over time. In ...

This article is excerpted from Rails for Java Developers, by Stuart Halloway and Justin Gehtland, with permission of The Pragmatic Programmers. All rights reserved ...