It needs having installed on your system a Sun Java 5 compatible compiler.
You can install it parallel to the usual open-jdk, usually already present on your machine.
Check that's not already on your machine for any reason with:
You have to follow some easy steps:
sudo apt-get install sun-java6-jdk
sudo update-alternatives --config java and chose the sun-java one
Set two values into your
~/.bash_profile or your
~/.bashrc (according to your system you could find any of them) :
export JAVA_HOME=<path to the folder of your jdk>(ex. )
export PATH=$PATH:<path to the bin folder within your jdk's dir>(ex. )