How to install Java so I can run some Paypal Java command line?

Hi,

I'm reading this page by Paypal to make the Paypal buttons more secure:
https://developer.paypal.com/docs/classic/paypal-payments-standard/integration-guide/encryptedwebpayments/#id08A3I0P017Q

by running this command line in Java:
java ButtonEncryption CertFile PKCS12File PPCertFile Password InputFile OutputFile

but I don't have the java command installed.

It's hosted by a VPS server on Godaddy using WHM/cPanel. I'm trying to find out the best way to install Java so I can run that command line.

It's Centos 5.9.

I read this:
http://stackoverflow.com/questions/5104817/how-to-install-java-sdk-on-centos

But this page says to install Tomcat:
http://www.jangro.com/how-to-install-java-on-whm-and-cpanel/

I have limited knowledge of Java (learning it though). Should I install Tomcat via WHM EasyApache? If so, I have this option to install "Mod Ruid2" (see attachment snapshot) in WHM EasyApache.

Or should I use the suggestion by the stackoverflow answer and use yum?

Thank you.
Screenshot-2014-01-13-03.32.05-v.png