Java Servlet Programming, 2nd Edition

Chapter 12. Enterprise Servletsand J2EE

This chapter discusses enterprise servlets. The term enterprise is used all the time with Java these days, but what does it mean? According to my trusty and beat-up copy of The American Heritage Dictionary (so old it’s priced at $1.95) the word enterprise has three definitions:

1. An undertaking, esp. one of some scope and risk

2. A business

3. Readiness to venture; initiative

It’s a surprisingly close definition to what people mean when they say enterprise Java and enterprise servlets. We can merge the traditional definitions to create a modern definition:

1. Readiness to support a business undertaking of large scope

In other words, enterprise servlets are servlets designed to support business-oriented large-scale web sites—high-traffic, high-reliability sites that have extra demands for scalability, load balancing, failover support, and integration with other Java 2, Enterprise Edition (J2EE) technologies.

As servlets have become increasingly popular and robust, and as servlet containers have become more solid and featureful, a growing number of enterprise sites are being built using servlets. Writing servlets for these sites differs from writing servlets for traditional sites, and in this chapter we’ll discuss the special requirements and abilities of these enterprise servlets.

Distributing Load

For high-traffic and/or high-reliability sites, it’s often desirable to distribute the site’s content and processing duties across multiple backend servers. This ...