The below steps should allow you to get standard Java setup on your Ubuntu box:

Add the repository
First create a new .list file for the repository

sudo gedit /etc/apt/sources.list.d/java.list

Paste in the following

deb http://archive.canonical.com/ lucid partner

Now update all repositories and install Java

sudo apt-get update && sudo apt-get install sun-java6-jre sun-java6-fonts sun-java6-plugin

Now you need to make sure that the version of Java you just installed is selected as the default Java installation on your system:

sudo update-alternatives --config java

Choose the version of Java you just installed.

Finally, we need to install the Java plugin in Firefox:

mkdir -p ~/.mozilla/plugins

Make a symlink to the Java plugin:

ln -s /usr/lib/jvm/java-6-sun/jre/lib/i386/libnpjp2.so ~/.mozilla/plugins/libnpjp2.so

Finally, you may want to implement the following fix which resolves the problem of Chinese characters displaying as 口口 boxes in Java applications:

cd /usr/lib/jvm/java-6-sun/jre/lib/fonts
sudo mkdir fallback
cd fallback
sudo ln -s /usr/share/fonts/truetype/arphic/uming.ttc .
sudo ln -s /usr/share/fonts/truetype/arphic/uming.ttc uming.ttf

Now restart Firefox and everything should be working OK! If you do run into any problems, you may want to consider uninstalling OpenJDK completely as well as the Icedtea Java plugin using Synaptic package manager.

Thanks to Felix Yan’s and Buckynasty’s original posts.

Many of you will already be familiar with reCAPTCHA via other websites – where it is often used to block spam comments on blogs or on user registration forms. Basically, it requires you to recognize two words in a picture and to type them into an input box as a means of proving that you are a human and not a spambot. You can see an example of reCAPTCHA in action in the screenshot provided.

I currently have the plugin setup so that it is activated on:

• New user registration
• Creation of new pages
• Anonymous edits that contain new external links
• Brute-force password cracking

If you are interested in implementing the plugin on your own blog, there is more information available here. It is a very straightforward and simple procedure.