Ok, Java4k applets dont really run in your normal Ubuntu (Kubuntu, Mint) etc installation,
since The OpenJDK IcedTea Plugin is … well not capable to run them.
There are several tutorials online showing how to replace the OpenJDK JVM with the one from Oracle.
Anyhow, here my method of using a local Orcale JRE to run Applets on Firefox without replacing your OpenJDK
Manually Installing Orcale(Sun) Java in Ubuntu for Firefox
#1 get the JRE
go to the Oracle Java Downloadsite
download the current Linux release, for example: jre-7u13-linux-i586.tar.gz
extract the *.tar.gz folder into your Homefolder (I just used the normal Archive Manager here)
copy it to:
So you have the all the runtimefiles in your private Homefolder
Ok, its not the “propper” way to install it in you homefolder,
but you have more control over your Java installation this way.
(like your own portable installation)
And can run it independent of your current Java installation.
#2 make a Link to /lib/i386/libnpjp2.so
now you need to make a symbolic link to the
file in the Firefox plugin directory.
go to :
check if the libnpjp2.so link is in this folder, if yes remove it
now create a symbolic link to the file in the Java-runtime folder:
sudo ln -s $HOME/javaInstallations/jre1.7.0_13/lib/i386/libnpjp2.so
this should now run your Oracle Java in FireFox on Ubuntu
#3 Test it
You could run FireFox from a terminal to see the log-output, and verify wich version of the JRE
(when starting a Java Applet at Java4k.com for example)