Java SOA Cookbook

Chapter 14. Enterprise Service Bus

Introduction

In this chapter, we’ll diverge from the problem/solution format used in the rest of this book in order to present an overview of an enterprise service bus (ESB). We’ll look at what an ESB is and what problems it solves. We’ll also examine some of the popular ESBs in the commercial and open source arenas to give you a solid foundation for selecting one that best suits your environment.

We’ll take a tour of the JBI specification, design patterns that form the foundation of ESB, and some key features of any implementation. We’ll also look at what some of the important players in the ESB space (including free and open source projects) are doing with their products.

Focus of This Chapter

Throughout most of this book, we have focused on standards published by the W3C, OASIS-Open, OAGI, Sun, and other organizations. They allow vendors to implement the specifications or recommendations. Vendors can then add their own proprietary extensions to be more competitive in the marketplace. In some cases, functionality of any specific implementation (such as the deployment of a component) is left entirely to vendors because the specifications are silent on certain matters viewed as beyond its scope. The standards for Java APIs, XML-related technologies, BPEL, and especially WS-* have allowed us to create solutions that, for the most part, are portable across such implementations. A JAX-WS web service will work in roughly the same way in any container that ...