Even if you install the rpm or sources from Sun the JRE plugin is not enabled by default under Firefox that shipped with latest OpenSuSE 13.1.
To sort out this just follow the simple steps outlined below.
Step 1: Locate the extenstion in your system. Type:
linux # locate libnpjp2.so
In my exmple the .so file is locate under /opt/java/64/jre1.7.0_51/lib/amd64/libnpjp2.so which is based on Sun JAVA 1.7.0_51 version.
Step 2: Symlink the file and done. Type:
ln -s /opt/java/64/jre1.7.0_51/lib/amd64/libnpjp2.so /usr/lib64/browser-plugins/libnpjp2.so
That's all. Type in your Firefox url tab the following:
and hit enter. You should be able to see something like:
Java(TM) Plug-in 10.51.2
Next Generation Java Plug-in 10.51.2 for Mozilla browsers