Looking inside the Object class

I finished reading the Joshua Bloch's chapter on "Methods common to all objects", from his book "Effective java programming language". The chapter is online: http://www.dcs.qmul.ac.uk/~mmh/APD/bloch/chapter3.pdf

It expalins succintly about the methods that are common to all java objects, with a fantastic explanation about how the equals() method should be implemented. Barbara Liskov, the MIT professor who is a bigshot on object oriented programming, has a different opinion on overwriting the equals method - which is based on mutable and immutable type.s

Bloch also explains the close() and the hashcode() methods clearly. A book worth reading.