[java] How can I use pointers in Java?

As others have said, the short answer is "No".

Sure, you could write JNI code that plays with Java pointers. Depending on what you're trying to accomplish, maybe that would get you somewhere and maybe it wouldn't.

You could always simulate pointes by creating an array and working with indexes into the array. Again, depending on what you're trying to accomplish, that might or might not be useful.