JSP compiler needs to use the sun.tools.javac.Main class to translate JSP into servlet code and then compile it into .class file. This class is in tools.jar file.
To make this tool.jar file available to Tomcat,
you need to set Windows environment variable JAVA_HOME.
Tihs can be done in either of the following ways:
1) In MS-DOS, issue: set JAVA_HOME=C:\jdk1.2.2
2) At the very beginning of tomcat.bat,
I took Windows as an example. You owrk on Linux, but things are similar. For instance, you work on tomcat.sh file.
You can visit www.apache.org and find FAQs.