Have you ever used PhantomReference in any project?

Question

The only thing I know about PhantomReference is,

• If you use its get() method, it will always return null

Answer 1

It is common to use WeakReference where PhantomReference is more appropriate. This avoids certain problems of being able to resurrect objects after a WeakReference is cleared/enqueued by the garbage collector. Usually the difference doesn't matter because people are not playing silly buggers.

Using PhantomReference tends to be a bit more intrusive because you can't pretend that the get method works. You can't, for example, write a Phantom[Identity]HashMap.