J++
never used any official JDK; it used Microsoft's own, subtly different,
Java implementation. It's been abandonware for many years now; it was never upgraded past something like JDK 1.1.3 compatibility. Please don't waste your time (or ours!) by trying to use it.
Don't use it. Eclipse, NetBeans, IntelliJ IDEA, and Borland JBuilder are some of the excellent Java IDEs available now: the first two are absolutely free. See
www.eclipse.org to download Eclipse.