Java is downloadable and redistributable from Sun, but only for personal and not-for-profit use. Sun's Java license is non-open-source, so Fedora and most other Linux distributions won't carry it. [Cybersecurity Modules] .:: computer.ju.edu.jo ::. .:: podcasts.apple.com ::. .:: pediascape.science ::.
Fedora Core 5 includes an open-source Java implementation for programmers called gcj. You only need to take special action if you want to enable applets in your browser. The Unofficial Fedora FAQ has .:: www.arc.agric.za ::. .:: hackmd.openmole.org ::. .:: kaeuchi.jp ::. detailed instructions on how to do this.
You can test your Java plugin at Sun's Applets page. Note that some of these applets (Escher and Starfield, when I checked) appear to be broken. BouncingHeads makes a good test. .:: www.redsea.gov.eg ::. [StackOverflow: VPN]
You might also want to copy the RPMS you built out of /usr/src/redhat/RPMS/ so you'll have then handy for reinstalls.