Java¶

Using Java applications/applets on your XO-AU OS.

Due to space considerations, we do not include a Java runtime in our XO-AU OS. It must be manually installed.

Here we will recognise the Sugar is intended as a learning platform for children based on constructivist principles. Java does not work too well with Sugar for technical reasons, and as a compiled language there is no ability to inspect or modify source code. In practice this is not a problem, as Java is normally used for more 'grown-up' applications. Hence, it makes more sense to use GNOME to run Java code.

These steps will show how to install the OpenJDK package from the Fedora repositories. This will take 90M of space, and you will need at least 350M free in total for the installation to work.

First, some caveats:

• Java can be slow to load and run, especially on an XO-1
• the OpenJDK in Fedora 11 is not quite as compatible as the official Sun/Oracle JRE. If you have problems, try to install the official JDK yourself.

To install:

1. switch to GNOME
2. connect to the Internet
3. open a terminal (Applications > System Tools > Terminal)
4. in the terminal, switch to root
   

   $ su -
   

5. unmount the yum cache directory, as explained on the Updating page
6. now we can install the package:
   

   # yum -y install java-1.6.0-openjdk-plugin
   

7. be patient as the packages download and install

Then you're ready to test your Web browser plug-in:

1. you may need to reboot your XO
2. open Firefox
3. go to the official test page
4. be patient while the applet loads
5. if successful, you should see an applet that says "Your Java is working"