Introduction

In this chapter

This Book Is for You

How This Book Is Organized

Conventions Used in This Book

Welcome to Enterprise JavaBeans 2.0! As part of the Java 2 Enterprise Edition (J2EE), the Enterprise JavaBeans architecture has become the accepted standard for the development of distributed, mission-critical business applications. The Enterprise JavaBeans (EJB) specification turns J2EE application servers into a foundation for building applications that are secure, transactional, scalable, and portable. If you develop large-scale business systems and you've never used EJB, now is the time to join the momentum that's thriving on an ever-growing number of success stories. If you already use EJB, the 2.0 Specification offers you even more in the way of productivity and component portability.

What is EJB? EJB is a specification for a server-side component architecture. Not to be confused with regular JavaBeans, EJBs are industrial-strength components that encapsulate reusable business logic and access to external resources such as relational databases for an enterprise. Foremost among the goals for EJB is that it makes it possible for developers to focus on business logic without having to worry about the low-level details of the life cycle, transactional, security, and persistence needs of their applications. These requirements are handled for you in a way that enables you to create components that are portable across application servers ”thus meeting another goal of the architecture. On top of everything else, EJB takes stock in the fact that the value of a component often is measured in terms of its reusability. EJB takes a declarative approach for deploying applications that supports extensive customization of components without requiring changes to the code.

The EJB specification was first introduced by Sun Microsystems alone, but it has now matured to its current form through the Java Community Process (JCP). Benefiting from the participation of the leading application server and software vendors , EJB 2.0 will almost certainly continue the success of the architecture.