This is the original way to
add software to your Java environment, and it works
on a JDK 1.1-based system and
on many Java implementations that
aren't derived from Sun's JDK. You may
prefer this technique if you have to make several
different Java execution environments cooperate -- perhaps one for each IDE and test environment
used for application development. You could also have
your application use its bundled JVM
when it's deployed, rather than whatever the end
user happened to have around.
The details vary from operating system to
operating system, and from installation to
installation, because you may need to ensure that your
CLASSPATH includes libraries internal to the JVM.
Put the CLASSPATH assignment into your login
script (autoexec.bat or your environment variables, .profile, .login, or other file). On Windows, you'll likely need to reboot after you modify autoexec.bat, to ensure that all new JVM instances see the new configuration.