Install Sun Java Packages
Ubuntu may use OpenJDK by default, but I note that some web services such as ezyZip.com might need the Sun Java Runtime Environment (JRE) to be installed in the system for running the services properly. If you would like to get the proprietary Sun Java packages for your system, you can download and install them from the Canonical Partner Repository with the steps below:
Go to Applications (or Main Menu) > Accessories > Terminal.
Enter sudo add-apt-repository "deb http://archive.canonical.com/ lucid partner" to add the partner repository.
Enter sudo apt-get update to update the source list.
Enter sudo apt-get install sun-java6-jre sun-java6-plugin sun-java6-fonts to download and install the Sun Java packages. (If asked to accept the Distributor License for Java (DLJ) terms, use the left/right key to navigate and select Yes, then press the Enter key for installation).
Enter sudo java -version to check the version of the Java used in the system.
Enter sudo update-alternatives --config java to choose the default Java for use in the system when necessary.