Apache: The Definitive Guide, 3rd Edition

Chapter 18. mod_jserv and Tomcat

Since the advent of the Servlets API, Java developers have been able to work behind a web server interface. For reasons of price, convenience, and ready availability, Apache has long been a popular choice for Java developers, holding its own in a programming world otherwise largely dominated by commercial tools.

The Apache-approved method for adding Java support to Apache is to use Tomcat. This is an open source version of the Java servlet engine that installs itself into Apache. The interpreter is always available, without being loaded at each call, to run your scripts. The old way to run Java with Apache was via JServ — which is now (again, in theory) obsolete on its own. JServ and Tomcat are both Java applications that talk to Apache via an Apache module (mod_jserv for JServ and mod_jk for Tomcat), using a socket to get from Apache to the JVM.

In practice, we had considerable difficulty with Tomcat. Since mod_jserv is still maintained and is not (all that) difficult to install, Java enthusiasts might like to try it. We will describe JServ first and then Tomcat. For more on Servlet development in general, see Jason Hunter’s Java Servlet Programming (O’Reilly, 2001).