implimenting interface methods

Posted on 2006-11-23
Last Modified: 2008-02-01
hi experts

if i have  5 methods in an interface , in my implimentation class do i have to impliment all the 5 methods of that interface?
or can i impliment less than 5

Question by:jaggernat
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LVL 14

Assisted Solution

hoomanv earned 35 total points
ID: 18004474
If you don't implement all of them, your class becomes abstract and you wont be able to create a complete instance
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Author Comment

ID: 18004495
so do u think i should impliment all 5 methods?
LVL 12

Accepted Solution

enachemc earned 65 total points
ID: 18004515
yes, this is the point of interfaces. You must implement all methods. If you provide an empty implementation of a method, just throw an uncked exception (NotSupported, NotImplemented) ...
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LVL 10

Expert Comment

ID: 18004522
Yes, although for some java interfaces there are adapters, from which you can extend. These implement the interface in a default way. For example:

class WListener extends WindowsAdapter implements WindowListener

Now you can override only those methods that you want to implement.

Notice that this requires an adapter class. Other solution is as sketch by hoomanv.

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Author Comment

ID: 18004533
>>>If you provide an empty implementation of a method, just throw an uncked exception (NotSupported, NotImplemented)

what is uncked exception?

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Expert Comment

ID: 18004575
an exception that you do not have to declare that you throw and you are not obligated to catch.
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Author Comment

ID: 18004590

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