what is the difference between == operator and equals()? (with hashcode() ???)

Question

I was learning hashcode in more depth and figured that:

1. If you override equals(), you must override hashcode() too.

2. To find if

Answer 1

If you don't already have a copy; buy a copy of Effective Java by Joshua Bloch.

This is the de facto reference for Java developers and has a lot of information on this (and many other) subject.