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HFSJ - Web App Deployment - Question 8 (Page 613)  RSS feed

 
Edisandro Bessa
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Hi guys,

Could you please give me some clue on this question telling why option C is NOT correct ?

Which statements about <init-param> DD elements are true ?

a) CORRECT - They are used to declare initialization parameters for a specific servlet.

b) INCORRECT - They are used to declare initialization parameters for an entire web app.

c) INCORRECT - The method that retrieves these parameters returns an Object ?

I know the method this option is referring to is getInitParameter which takes and returns a String. My question is : If this method returns a String, doesn't it return an Object implicitly ?

d) CORRECT - The method that retrieves these parameters takes a String.
 
Firas Zuriekat
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If this method returns a String, doesn't it return an Object implicitly ?


(string instanceof (Object)) is True
(object instanceof (String)) is False.

So an object (an instance of Object) is not a a String.
So getInitParameter() does not return object. This is because Object is neither a subtype nor an implementer of String. If it were, then we could safely say getInitParameter() returns the subtype Object. But it isn't so we can't that.
[ September 10, 2006: Message edited by: Firas Zuriekat ]
 
Niranjan Deshpande
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Please refer to

http://www.oreilly.com/catalog/headservletsjsp/errata/headservletsjsp.confirmed

and search for page {608}. This is a printing mistake.

Hope that helps
 
Edisandro Bessa
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Hum ...

After read the errata you posted above everything makes sense.

Thanks Niranjan for your valuable tip and Firas for your prompt reply.
 
Don't get me started about those stupid light bulbs.
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