(Dude, chill! He obviously hasn't got a technical bone in his body!)
Java is not server based, it's just a runtime environment. It's got nothing to do with DirectX.
You can run Java on a client, with absolutely no access restrictions, in the form of applications; or you can run Java in a special restricted form using Java Web Start, which assigns specific permissions based on a server's trusted certificates; or you can run in fully-restricted client form, as an applet embedded in a web-page, where you have access only back to the server you got the applet from.
In the case of a gambling site I would be certain to refuse download of any gambling application that required access to my harddrive because I don't trust the f**kers. I'd even be dubious about accepting a signed application over Webstart, such is my level of distrust of these scumsuckers. But an applet would be acceptable because I'm fairly convinced that it's secure.
Anyone non-technical, like yourself, would probably happily download any old trojan/virus/spyware and type your credit card details into it so it may be a moot point.
Server side, you can do pretty much whatever you want in Java. DirectX of course is not a server technology.