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Request Attribute confusion

 
Joe Harry
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Guys,

I tried the following,

My test.jsp,


But if I comment Line 1, I'm getting a null pointer?? I know the request.getAttribute("jothi") in the System.out.println(request.getAttribute("jothi")) gets a call to toString90 method but why the other throws a null pointer??
 
Srinivasan thoyyeti
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Hi Jyothi,


When you first request the jsp file

1. jsp converted to servlet and in service attribute jyothi placed.
2. and in response html form sent.
3. your request ends here.(that means your request,response objects gone).


secondly when user submits the form

1. control reaches servlet
2. tries to find jyothi in request scope.
finally gives up return null.

[ May 11, 2007: Message edited by: Srinivasan thoyyeti ]
 
Christophe Verré
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Try the following :


You are using a java1.5 feature called unboxing, which converts an Integer into an int.
But you are trying to convert null into an int, which fails.
It would work with Integer i = (Integer)request.getAttribute("jothi");

Maybe you'd better use SDK1.4 to practice for this exam.
 
Joe Harry
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Satou,

You are really amazing. No words to praise you man. You point out my mistakes elegantly. Thanks!
 
Joe Harry
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Consider the code as below,



I'm confused as when I run this I'm getting shanar as the o/p. Shouldn't the forward call in includedjsp.jsp ignore anything that we set???

 
It is sorta covered in the JavaRanch Style Guide.
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