The other important environment variable is called CLASSPATH. The CLASSPATH variable helps the Java runtime find various classes needed by an application. Usually, these Java classes are grouped together in a single JAR (Java Archive) file. Tomcat has several such JAR files that include classes for XML parsing, Servlets, and the JSP compiler. You can find them in the "lib" directory. Tomcat automatically appends the location of its jar files to your existing CLASSPATH.
Warning: Sometimes the process of appending the jar file location to your CLASSPATH environment variable causes the variable size to exceed the maximum allowable size. The tomcat.bat file contains a description of how to make the appropriate modifications manually.
Another point to consider is that JSP pages must be compiled the very first time someone accesses the JSP page. This compilation process converts the JSP page into a Servlet. This requires access to the Java compiler. Tomcat will not be able to call the Java compiler if the directory path to the Java compiler includes spaces. To avoid the problem, install the JDK in a directory with a name that contains no spaces, such as JDK1.3.
After starting Tomcat, open your browser and type the following URL: http://localhost:8080. Tomcat uses port 8080 by default, so make sure that port is not being used by another server, such as Internet Information Server (IIS). If there is a port conflict, you can change Tomcat's default port by modifying the file server.xml in the conf directory. Search for the number 8080 in the file and change it to an unused port number. When Tomcat starts successfully, you will see an introduction page in your browser similar to Figure 2
There are two links towards the middle of the page pointing to Servlet and JSP examples. You should click on a few examples to make sure everything is working correctly.