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Please answer the following HF question (Page 703) on filters

 
Firas Zuriekat
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Which about filters are true?

A- Filters may be used to create request or response wrappers
B- Wrappers may be used to create request or response filters

Correct answer is A (answer is on page 703)

Why is the answer is A? On what page should I look in order to see an example that Filters may be used to create request or response wrappers. I only see that you could extend wrappers.

I don't know if it's related but on page 689 it also shows that by extending an HttpServletResponseWrapper, the filter could get custom Response object that it sends to the servlet. Then that servlet could write output to that custom Response. So p689 doesn't try to show that filters may be used to create response wrappers.
[ December 24, 2006: Message edited by: Firas Zuriekat ]
 
Sayak Banerjee
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Yeah...even I'm confused....how can a Filter be used to create Wrappers....as far as I know, you can subclass one of these Wrapper classes to obtain a custom response or request object which you pass to the chain.doFilter() method? That's it....I really fail to understand how Filter's can be used to create Wrapper's.

Could anyone please explain....Many thanks in advance.
 
Renu Radhika
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By extending wrapper classes,we are creating custom wrapper classes.

So if you have specified a filter which extends these wrappers then you are using filters to create custom wrappers
 
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