1) I assume you downloaded the file with a .bin extension. Simply open a terminal, and type ./jdk1.3.1_16.bin - or whatever the name of the file is. You will need to be root, an install it to /usr/local.
2) Edit the file /etc/profile as root. Add the line
Where you have installed java to /usr/local/java.
3) Log out and back in again, and try the command
, and you should get Java's version printed on the screen.
Just some queries:
1) I hope you're not running as root all the time. This is really bad - set up a normal user, and only use the root account when you really need to.
2) Why are you installing Java 1.3? I think the latest version is 1.5.
I hope this helps