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Why base class's static method shows up in derived class?

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  Why base class's static method shows up in derived class? Stone Zhong <stone.zhong@gmail.com> - 2015-01-04 23:52 -0800
    Re: Why base class's static method shows up in derived class? Patrick Roemer <sangamon@netcologne.de> - 2015-01-05 13:07 +0100
    Re: Why base class's static method shows up in derived class? v_borchert@despammed.com (Volker Borchert) - 2015-01-05 22:12 +0000

#30629 — Why base class's static method shows up in derived class?

Hi there,

Can anyone share some experiences with this weird behavior:

With the code snipped below:

        for (Method method: HttpClientContext.class.getMethods()) {
            if (method.getName().equals("create")) {
                System.out.printf("%s%n", method);
            }
        }


I got output:
public static org.apache.http.client.protocol.HttpClientContext org.apache.http.client.protocol.HttpClientContext.create()
public static org.apache.http.protocol.HttpCoreContext org.apache.http.protocol.HttpCoreContext.create()


HttpClientContext derived from HttpCoreContext. Both class has a static method "create" with no parameter. 

Why HttpCoreContext.create shows up as HttpClientContext's method? I am expecting only "public static org.apache.http.client.protocol.HttpClientContext org.apache.http.client.protocol.HttpClientContext.create()" to show up, am I missing anthing?

Thanks,
Stone

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#30630

Responding to Stone Zhong:
> With the code snipped below:
> 
>         for (Method method: HttpClientContext.class.getMethods()) {
>             if (method.getName().equals("create")) {
>                 System.out.printf("%s%n", method);
>             }
>         }
> 
> 
> I got output:
> public static org.apache.http.client.protocol.HttpClientContext org.apache.http.client.protocol.HttpClientContext.create()
> public static org.apache.http.protocol.HttpCoreContext org.apache.http.protocol.HttpCoreContext.create()
> 
> 
> HttpClientContext derived from HttpCoreContext. Both class has a static
> method "create" with no parameter. 
> 
> Why HttpCoreContext.create shows up as HttpClientContext's method? I am
> expecting only "public static org.apache.http.client.protocol.HttpClientContext
> org.apache.http.client.protocol.HttpClientContext.create()" to show up,
> am I missing anthing?

Class#getMethods() returns (public) methods inherited from superclasses
and interfaces as well. Static methods from direct superclasses are
inherited just as instance methods. So in general it's fine that static
methods of the superclass show up in the output of #getMethods().

What puzzles me in this specific case is that both methods have the same
signature. To my understanding, according to JLS8 §8.4.8, the
superclass' #create() method should not be inherited because of the
subsignature relationship...

Best regards,
Patrick

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#30637

Stone Zhong wrote:

> [ ... ] am I missing anthing?

Yes - Class.getDeclaredMethods()

-- 

"I'm a doctor, not a mechanic." Dr Leonard McCoy <mccoy@ncc1701.starfleet.fed>
"I'm a mechanic, not a doctor." Volker Borchert  <v_borchert@despammed.com>

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