doFilter method of the Filter is called by the portlet container each time a resource request/response pair is passed through the chain due to a client request for a portlet method at the end of the chain. The FilterChain passed in to this method allows the Filter to pass on the resource request and response to the next component in the chain.
The doFilter method of a filter will typically be implemented following this or some subset of the following pattern:
ResourceRequestWrapper in order to modify request data.doFilter method with a customized implementation of the response wrapper ResourceResponseWrapper to modify response data.doFilter method on the FilterChain object, and passing in the request and response with which it was called or passing in wrapped versions it may have created. The filter chain�s implementation of the doFilter method, provided by the portlet container, must locate the next component in the filter chain and invoke its doFilter method, passing in the appropriate request and response objects. Alternatively, the filter chain can block the request by not making the call to invoke the next component, leaving the filter responsible for filling out the response object.UnavailableException during its doFilter processing, the portlet container must not attempt continued processing down the filter chain. It may choose to retry the whole chain at a later time if the exception is not marked permanent. | |
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