Introduction

Contents:

Enterprise Computing Defined
Enterprise Computing Demystified
The Java Enterprise APIs
Enterprise Computing Scenarios
Java Enterprise APIs Versus Jini

This tutorial is an introduction to, and quick reference for, the Java Enterprise APIs. Some of these APIs are a core part of the Java platform, while others are standard extensions to the platform. Together, however, they enable Java programs to use and interact with a suite of distributed network services that are commonly used in enterprise computing.

Just before this tutorial went to press, Sun announced a new Java platform for enterprise computing. Java 2 Platform, Enterprise version, or J2EE, is the standard Java 2 platform with a number of extensions for enterprise computing. As of this writing, J2EE is still in its alpha stages; it will be some time before a complete specification and implementation are delivered. From the preliminary specifications, however, it appears that most of the enterprise-computing technologies that will be part of J2EE are already documented in this tutorial. In the months ahead, you will undoubtedly hear quite a bit about Java 2 Platform, Enterprise version. Although you won't find that name used explicitly here, you can rest assured that this tutorial documents the building blocks of J2EE.

Enterprise Computing Defined

Before we go any further, let's be clear. The term enterprise computing is simply a synonym for distributed computing: computation done by groups of programs interacting over a network.

Anyone can write distributed applications: you don't have to work for a major corporation, university, government agency, or any other kind of large-scale "enterprise" to program with the Java Enterprise APIs. Small businesses may not have the same enterprise-scale distributed computing needs large organizations have, but most still engage in plenty of distributed computing. With the explosive growth of the Internet and of network services, just about anyone can find a reason to write distributed applications. One such reason is that it is fun. When distributed computing is used to leverage the power of the network, the results can be amazingly cool!

So, if the Java Enterprise APIs aren't used exclusively by enterprises, why aren't they called the Java Distributed Computing APIs? The reasons are simple. First, enterprise is a hot buzzword these days--everyone in the networking industry wants to be doing enterprise something. Second, large enterprises have lots of money to spend on costly hardware for running their expensive network server software. Since the enterprise is where the money is, we get the word enterprise in the APIs.