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<jsp:useBean> unexpected behavior

 
Shwetha Sharma
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Eclipse IDE Java MySQL Database
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In servlet if we have


jsp code :


In the generated servlet:


Runtime exception is thrown



and in case we have something apart from null in the request attribute:


the generated servlet has:


Why the null condition has diffeent behaviour in both cases in the generated servlet?
 
Royston Monteiro
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Whooaah! Very strange.

From what I have learnt, I think the generated servlet for a given jsp should be the same irrespective of what some other servlet does before calling it.

Could someone please clarify.

ps: which container are you using?
 
Chinmaya Chowdary
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Hi, Shwetha.

Can you please post, how you are accessing jsp:useBean in the above case?
 
Shwetha Sharma
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I missed the difference in usage.

If we dont specify the class attribute for the jsp:use bean, then Instanciation Exception is thrown in case the bean is not present in session or its null




results in



and in case we give class attribute


results in


 
Adeel Ansari
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From the syntax ref:

The <jsp:useBean> element locates or instantiates a JavaBeans component. <jsp:useBean> first attempts to locate an instance of the Bean. If the Bean does not exist, <jsp:useBean> instantiates it from a class or serialized template.
 
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