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    <p>Here's my opinion.</p> <p>First of all, the Abstract Factory pattern is not intended to be a factory of factories. The key aspect of this pattern is that there is an accessible interface with an underlying (probably inaccessible) factory implementation through which you can get accessible interfaces of (probably inaccessible) object implementations. I know, is a long nasty wordplay of how I understand some of the applicability conditions of this pattern in Gamma's book:</p> <blockquote> <ul> <li>a system should be independent of how its products are created, composed, and represented</li> <li>you want to provide a class library of products, and you want to reveal just their interfaces, not their implementations.</li> </ul> </blockquote> <p>At the end you're getting objects, not factories.</p> <p>Second, I wouldn't make 1:1 relationships between pattern concepts and language keywords. "Abstract Factory" does not necessarily always translate to the Java <code>abstract class</code> or <code>interface</code> constructs. You can still have a regular, extendable, instantiable class that represents an "Abstract Factory" as long as you somehow guarantee that the client code is independent of the underlying factory and object implementations. This is the case of <code>java.lang.Class</code>, which is not abstract nor an interface, but does the job at hiding the parameterless constructor implementation of the type it represents through the <code>newInstance()</code> method. It's probably clearer if you use it like:</p> <pre><code>Object o = Class.forName(type).newInstance(); </code></pre> <p><code>Class</code> plays the "Abstract Factory", and <code>Object</code> plays the "Abstract Product" to the type implementation. </p> <p>Last, <code>newInstance()</code> is not a static factory method, I think because this pattern is intended to return instances of the class it is implemented on. <code>newInstance()</code> does not return instances of <code>Class</code> nor sub-<code>Class</code>es. It returns instances of the type it represents. It neither is a "Factory Method" just as Bloch states in his book.</p>
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    1. PODoes Class.newInstance() follow the "Abstract factory" design pattern?
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    1. PODoes Class.newInstance() follow the "Abstract factory" design pattern?
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    1. COBingo! That is what I was looking for. Thanks for the detailed explanation.
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      1. USdivesh premdeep
    2. CO*[Class] does the job at hiding the parameterless constructor implementation of the type it represents.* I completely disagree, `newInstance()` hides nothing. To call the constructor directly, you need to know that a no-arg, visible constructor exists. To instantiate using `newInstance()`, you need to know that a no-arg, visible constructor exists. The behaviour of `newInstance()` is well specified, so it really *can't* encapsulate anything of consequence. And in neither case do you need to be aware of the actual *implementation* of the constructor itself.
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      1. USMark Peters
    3. COMark, I agree with your statement that `Class.newInstance()` does not hide anything, i.e. the caller of this method must ensure that a no-arg constructor exists for the specified class instance. Applying the same line of thought to the factory pattern, if a client obtains a reference to a factory implementation (say, through injection) and invokes a method on it, shouldn't the client be sure that the injected factory instance does not simply implement all the factory interface methods to throw an `UnsupportedException`? In my opinion, rarely is anything *truly* transparent.
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