- To use UninstallJava, you first need to load J/Link using Needs["JLink`"].
- UninstallJava is provided mainly for developers who are actively recompiling Java classes for use in Mathematica and therefore need to shut down and restart the Java runtime to reload the modified classes.
- Users generally have no reason to call UninstallJava. The Java runtime is a shared resource used by potentially many Mathematica programs. You should leave it running unless you are absolutely sure you need to shut it down.