Doubt in requestScope

[raja ram]

Hi,
I have the following code

<%request.setAttribute("name","To test thekey and attribute differences");%>
<p>requestScope["name"]--------->${requestScope["name"]}</p>

This works fine also this.
<p>name--------->${name}</p>
but this doesnt work.

<%request.setAttribute("name","To test thekey and attribute differences");%>
<p>requestScope[name]--------->${requestScope[name]}</p>

I know that requestScope is a map containing all the request scoped attributes in it.
why does it fail when. I pass an attribute rather than a string.

Thanks
[ November 10, 2008: Message edited by: raja ram ]

[Christophe Verré]

Did you post the same code twice ? I can't see any difference.

[raja ram]

Hi,

I have edited the post.

Thanks

[Seetharaman Venkatasamy]

Originally posted by raja ram:


I know that requestScope is a map containing all the request scoped attributes in it.

you know , it is a map right? then how come it(below one ) will work?

   
 <p>requestScope[name]--------->${requestScope[name]}</p>
 
 

this will work

   
requestScope[name]--------->${requestScope.name}//  but  use ${requestScope["name"]} this,it  is  a  standard  way
 
 

Hope this helps

[Deepak Jain]

Code #1 uses requestScope["name"] to access the request attribute name. This will work as expected.
However requestScope[name] , Here name is without quotes so the

1) container will now search for a attribute "name" in all the 4 scopes one after other and it will find name in request scope with a value "To test thekey and attribute differences"

2) Container will now convert this to
requestScope["To test thekey and attribute differences"] and it will search again a attribute with name = "To test thekey and attribute differences" in all the 4 scopes and it will find none and since EL handles null gracefully it will return empty string.

To confirm the above explanation try this EL empty operator.

<%request.setAttribute("name","To test thekey and attribute differences");%>
<p>requestScope["name"]--------->${requestScope["name"]}</p>
<p>requestScope[name]--------->${empty requestScope[name]}</p>

Result:
requestScope["name"]--------->To test thekey and attribute differences
requestScope[name]--------->true

Hope its clear

[raja ram]

Hi,

Thanks for clearing my doubt.