These instructions are for i386 and AMD64 computers only. For PowerPC machines, see Ubuntu Help Online.
Install sun-java5-jdk (see Add Applications).
Read the Java licence presented. You must accept it to continue.
To get your system to use Sun Java instead of the open-source (but less functional) GIJ that is installed by default, run:
sudo update-alternatives --config java
and choose the option that has j2re1.5-sun
in it.
Java 1.6 is also available, and can be installed by following the above directions, swapping all instances of 1.5 to 1.6.
The Eclipse platform provides a complete, extensible Java development environment.
Install the eclipse package (see Add Applications).
Press → → .