So you’ve decided that identity isn’t enough for you and wrote a nice equals implementation? Great! But now you have to implement hashCode as well. Let’s see why and how to do it correctly.

It’s default implementation simply checks the object references of two objects to verify their equality. By default, two objects are equal if and only if they refer to the same memory location. Most ...

If you are fortunate enough to be using JDK 7 , the newly available Objects class is the obvious ( at least to me ) choice for implementing the "common" Java object methods such as equals (Object ...

The HashMap tutorial also includes some useful code snippets that help developers understand what's going on with a Java HashMap under the covers. For example, the following code used in the tutorial ...