For compiling servlet code download
Java(TM) 2 SDK, Enterprise Edition which contains an implementation of the Java Servlet 2.3 specification
from
http://java.sun.com/j2ee/sdk_1.3/ Then edit /etc/profile file in Linux
add <j2ee_home_directory>/lib/j2ee.jar to the classpath environment variable
present in /etc/profile
eg:
if initially file cotains
classpath=".;$JAVA_HOME/bin"
make it
classpath=".;$JAVA_HOME/bin;/usr/j2ee/lib/j2ee.jar"