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Modifying Parameters with Filters

Drew Lane
Ranch Hand

Joined: May 13, 2001
Posts: 296
I've been playing around with Filters trying to intercept/modify some parameters that get sent in by an HTML Form.

I can get the parameter with request.getParameter(), but how do I set it?

I can use request.getSession().setAttribute(), but I don't think this is the same thing.

I'm guessing I need to modify the request before calling doFilter().

Any help?


William Brogden
Author and all-around good cowpoke

Joined: Mar 22, 2000
Posts: 13036
You can't modify request parameters - what you have to do is make a custom HttpServletRequestWrapper extension. In your custom getParameter() and related methods, provide for catching the name of the parameter you want to "modify"
In the filter, replace the original request with the wrapped request.
I agree. Here's the link:
subject: Modifying Parameters with Filters
jQuery in Action, 3rd edition