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Why can't interfaces define a static method

Anupam Sinha
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Joined: Apr 13, 2003
Posts: 1088
Why can't interfaces define static methods?
Peter Chase
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Joined: Oct 30, 2001
Posts: 1970
The simple answer to all such questions is "because the Java Language Specification says so".

In many such questions, it would be possible to imagine how the feature under discussion might have been allowed. The language designers had to make judgements about what features would be useful, understandable, easy to implement in compilers/JVMs, and encourage good programming. Static methods in interfaces would fall down on several of those criteria.


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Ådne Brunborg
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Joined: Aug 05, 2005
Posts: 208
Another answer is that they can. But such interfaces are called "abstract classes" and not "Interfaces" . Abstract classes and Interfaces are very similar in nature - they are both abstract (i.e. cannot be instantiated), and defines method signatures.

The difference is mainly that abstract classes can define method implementations as well - including static methods.


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Ilja Preuss
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Joined: Jul 11, 2001
Posts: 14112
All methods in an interface are abstract. Static methods cannot be abstract, because they aren't polymorphic.


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Anupam Sinha
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Joined: Apr 13, 2003
Posts: 1088
Thanks to all of you for your replies. It was helpful.
 
 
subject: Why can't interfaces define a static method