I needed to get Java working with Firefox on my CentOS box. The primary reason was to do some additional NAC testing with Linux. I’ve been having a much harder time getting it installed than I originally thought. I finally got it working and wanted to share my steps and links.
1. Download the Java RPM from http://www.java.com. I used the self extracting file.
2. Create the /usr/java directory and place self extracting file there
3. Change the file to make it executable with “chmod a+x jre-6u21-linux-i586.bin”
4. Execute the file by typing “./jre-6u21-linux-i586.bin”
5. cd to the “/usr/lib/mozilla/plugins” directory
6. Create the following two symbolic links within that directory
ln -s /usr/java/jre1.6.0_21/plugin/i386/ns7/libjavaplugin_oji.so
ln -s /usr/java/jre1.6.0_21/lib/i386/libnpjp2.so
7. Close any open Firefox web browsers
8. Open a Firefox web browser
9. In the URL field, type “about:plugins”. You should see references to Java plugins.
There are a lot of references on the internet that have the first symbolic link shown above, but the only reference I found to the second symbolic link was the second reference below. That was the final step that made it work for me.