Java2 Standard Edition 1.4.2 SDK
If you are on Windows, Linux or Solaris, download J2SE 1.4.2 SDK from Sun. For other platforms, refer to the website for your platform. Make sure to download the SDK and not the JRE, as the Java Runtime Enviroment cannot be used to compile JSP files.
The following screendumps shows how to install J2SE 1.4.2_x SDK on Windows XP:
Now restart your server. If installing on Linux or Unix, it is normally not necessary to reboot the server after a Java install, unless your server vendor says otherwise. Also, on Unix/Linux it is necessary to set the JAVA_HOME enviroment variable in your shell to point to the directory where you just installed Java.