Who is asking? A human being (who can poke around the filesystem looking for it, just this once, and then know where it is, after that), or an application already running inside the JVM (that has to try finding it every time the application executes)?



Perhaps check if the "JAVA_HOME" environment variable is set; or look in the typical/usual places (what's the default, I forget? /usr/local/java? /usr/java? /opt/java? etc.); or use the RPM pkg mgr (pkginfo?), to see if it was installed via a package which records the location.