Posts

Enforce non-instantiability with private constructors

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Use Java enum to create Singletons

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Using Builder Pattern with Class Hierarchies

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Static Factory Method

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The Builder Pattern (using immutability)

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The Beauty of the Null Object Pattern

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Before we start... Let me start by saying this: NEVER dismiss an idea without giving it any consideration. That was the mistake I made when I first encountered an article about this design pattern many years ago. I was thrown off by the name and without even attempting to find out what this design pattern was all about, I moved on to other things. That was a huge mistake that I am not afraid to admit. I urge you not to make that mistake. And if you have already, never make that mistake again. Trust me, you will thank me later. For now, let me tell you my story and attempt to explain when to use it along with a simple example on how to implement this pattern. The Null Object Pattern By definition, the main purpose of this pattern is to an Object-Oriented alternative to the absence of objects by creating objects that display only "do nothing" behavior. That sounds like a mouthful. In simplest terms, it is meant to provide a mechanism to replace null object references