javax.xml.parsers.DocumentBuilderFactory,static newInstance's concrete implementation.

[Punya Pratap Singh]

javax.xml.parsers.DocumentBuilderFactory is a Abstract class .It has a newInstance method which returns a instance of type DocumentBuilderFactory .
how does this static method finds implementing concrete class.
Java have already gone through java docs and asking for simple and easy in depth explanation.

please explain ? Thanks

[Seetharaman Venkatasamy]

probably, newInstance method is instantiate a class[subclass of DocumentBuilderFactory] which is implementation of DocumentBuilderFactory.
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also, google for static factory method
</edit>

[Rob Spoor]

Inside the JDK installation folder there is a file called src.zip. You can open that to see the source code of most classes.

In this case, it uses a system property for the actual class name. If the system property is not found a default one will be used.