Required Libraries and Tools

In order to write and execute Java servlets, several software packages must be installed onto the machine that will be used to develop and compile the servlets. You will need to download and install the J2EE SDK from the Sun Java website. The servlet libraries will be included in the SDK. Because Java is platform-independent, the servlets don't have to be compiled on the server. It is possible to install the SDK and servlet libraries on another machine and perform the servlet development work there. The server will have to have a JVM installed on it so it can run the servlet.

The final bit of infrastructure to install is a Java web server. A web server is an application that runs in the background on a server and can send things such as HTML pages back to client browsers. A Java web server is one that can also execute Java servlets. There are many commercial Java web servers on the market today. There are also Java web servers that can be acquired without charge. The Tomcat and Apache servers, for instance, can be found at http://jakarta.apache.org.

For the servlet example in this chapter, the Apache web server with the JServ module was installed on an SGI workstation that was used as the server.