Among the types of functionality available to the developer needing to use filters are the following:
� The accessing of a resource before a request to it is invoked.
� The processing of the request for a resource before it is invoked.
� The modification of request headers and data by wrapping the request in customized versions of the request object.
� The modification of response headers and response data by providing customized versions of the response object.
� The interception of an invocation of a resource after its call.
� Actions on a servlet, on groups of servlets, or static content by zero, one, or more filters in a specifiable order.
Here is sthing that I extract from the
Servlet 2.4 Specification... Hope it helps you...
Co-author of SCMAD Exam Guide, Author of JMADPlus
SCJP1.2, CCNA, SCWCD1.4, SCBCD1.3, SCMAD1.0, SCJA1.0, SCJP6.0