It's useful to have an implementation of java installed for two reasons:
(1) To view java based applications in a web browser using a plugin
(2) To run native applications such as the molecule viewer jmol
In the past I've used Blackdown Java for Linux, and I see no reason to change now. The current version is, so go to one of the download sites and find the JDK-1.4.2/i386/rc11.4.2, and then download the appropriate software development or runtime environment file. This time I downloaded j2sdk-1.4.2-rc1-linux-i586-gcc3.2.bin (SDK includes the runtime environment). Make the downloaded file executable.
To install:
cd to the directory where java is to be installed, and execute the bin file:
$ cd /home/local/share $ ./j2sdk-1.4.2-rc1-linux-i586-gcc3.2.binThis creates a directory /home/local/share/j2sdk1.4.2, and puts all the executables into /home/local/share/j2sdk1.4.2/bin. Add the later directory to the path. Test the installation by seeing if jmol runs.
For the plugin, follow the notes in j2sdk1.4.2/INSTALL. For MozillaFirebird use the Mozilla directions, which amount to:
# cd /usr/local/MozillaFirebird/plugins/ # ln -s /home/local/share/j2sdk1.4.2/jre/plugin/i386/mozilla/libjavaplugin_oji.so .Test this by going to, say this page describing the cubic Laves crystal structure, and click on the visualize the structure link. If a window pops up and you can move the atoms around, things work. (Note: need javascript and java enabled in MozillaFirebird.)