If you want to program in Java, you'll need the SDK. I actually recommend getting the latest stable/patch release directly from Sun. While the Blackdown (blackdown.org) version is quite good, it lags a bit (obviously) from the Sun version.
If you just want to run Java programs, then just install the JRE by any of the methods mentioned above. The latest JRE RPM seems to be available from Dag's repository.
Linux User #28251 (April '93)
Professional Java Geek :cool: