Advanced BlockPopulator to create caves and ore veins

Hello,
I have done some really nice stuff with my own WorldGenerator, and I have added a block populator that randomly replaces stone with ores.
Now I want to go a step further: I want to have caves and realistic ore veins but I do not have a clue how to make such a block populator...

I know that people asking for stuff like "How can I do such and such" are kind of annoying, but I really searched on google and on BukkitDev and here in the Plugin Development Section, but all i found was an API that had a Dropbox downloadlink that has been taken down for "Too many traffic". Problem: The user who postet the API wasn't online for like a year or so.

So I would be really pleased if somebody could just give me an example code for how to place a cave or ore vein somewhere, I can change the code to fit into my world.

Thank you for being interested in this topic (because you have read so far)
jojohnson1

 

I think you could add the caves in your world generator using noise. About the veins you could probably do something like whenever you place an ore have a random select a boolean and if it is true place another ore next to it and so on until it returns false.