Where can I find the best reference to learn Design Patterns in Java?

Standard

Design Patterns in Java Tutorial Design patterns represent the best practices used by experienced object-oriented software developers. Design patterns are solutions to general problems that software developers faced during software development. These solutions were obtained by trial and error by numerous software developers over quite a substantial period of time. This tutorial will take you through step by step approach and examples using Java while learning Design Pattern concepts.

Prerequisites Before you start proceeding with this tutorial, I’m making an assumption that you are already aware about basic java programming concepts. If you are not well aware of these concepts then I will suggest to go through our short tutorial on Java Programming.

Reference:
Design Patterns Tutorial in PDF