EJB 3 Transactions

Sun, 28 Jan 2007 15:00:00 EST

Much of the work surrounding the design and development of enterprise applications involves decisions about how to coordinate the flow of persistent data. This includes when and where to cache data, when to apply it to a persistent store (typically the database), how to resolve simultaneous attempts to access the same data and how to resolve errors that might occur while data in the database is in an inconsistent state. A reliable database is capable of handling these issues at a low level in the database tier, but these same issues can exist in the middle (application server) and client tiers as well, and typically require special application logic.

Java Feature — Inheritance Hierarchies in JPA

Mon, 23 Oct 2006 13:45:00 EDT

The persistence model introduced in EJB 3.0 as a replacement for entity beans is known as the Java Persistence API (JPA). The JPA borrows from both proprietary and open source models, such as Oracle TopLink, Hibernate, Spring, and other frameworks, which have gained traction as popular alternatives to the often heavyweight and cumbersome persistence directives required by earlier EJB revisions. Among the new features introduced in EJB 3.0 through the JPA is support for entity inheritance. In this article, we will examine inheritance strategies supported by the JPA and apply these strategies to a simple entity hierarchy, exploring the strengths and weaknesses of each approach. This comparison is intended to help you understand how to set up entity hierarchies, and to decide which mapping approach to take for the entity hierarchies in your own application.

Latest News from Jonathan Wetherbee

EJB 3 Transactions

Java Feature — Inheritance Hierarchies in JPA