A little help please with private server

Ok well I'm working on learning to make my own server but unfortunantely I am ignorant to getting everything started. The part I'm having trouble is figuring out what java jdk I have because all I have found at the main site are jdk's mixed with other programs etc. and when I try to download a older version like java jdk 1.6.0_18 it takes me to the new versions or it takes me to sites just talking about java jdk no actual downloads.

So if anyone can help me with this problem I will be very thankful

 

JDK: (This is where the download sends me) https://cds.sun.com/is-bin/INTERSHO...ProductRef=jdk-6u23-oth-JPR@CDS-CDS_Developer

Then you will need to download a source and a client. The source is the coding for the game, the client is the window in which people can play it. You need both of these to run a server.

www.moparscape.org (go to the Forums section)
www.runelocus.com

Both of these websites have sources and clients for download.