There isn't a
single way to install a java program, and some you don't even have to "install" at all. Some you can just install like any other rpm from the "add software" tool in Mandriva.
Some java programs come with an installer, some don't. If you tell us which java program you'd like to install, we can try to help.
But it looks like you have a java runtime installed, so you can use that to run any java program you've downloaded. Usually this is done with the command
CODE
java ClassName
where "ClassName" is the name of the class you want to launch. Or if the program is packed in a jar file, you can do
CODE
java -jar myjavaprogram.jar
But usually any program you install via rpm will have a shell script or something to launch it, just look at each program's instructions.