public interface EventFilter extends PortletFilter
EventFilter
is an object that performs filtering
tasks on either the event request to a portlet, or on the event response from
a portlet, or both.
Filters perform filtering in the doFilter
method. Every Filter has
access to a FilterConfig
object from which it can obtain
its initialization parameters, a reference to the PortletContext
which it can use, for example, to load resources needed for filtering tasks.
Filters are configured in the portlet deployment descriptor of a portlet application.
Modifier and Type | Method and Description |
---|---|
void |
doFilter(EventRequest request,
EventResponse response,
FilterChain chain)
The
doFilter method of the Filter is called by the
portlet container each time a event request/response pair is passed
through the chain due to a client request for a portlet method
at the end of the chain. |
destroy, init
void doFilter(EventRequest request, EventResponse response, FilterChain chain) throws IOException, PortletException
doFilter
method of the Filter is called by the
portlet container each time a event 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 event 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:
ActionRequestWrapper
in order to modify request data.doFilter
method with a customized implementation
of the response wrapper ActionResponseWrapper
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.request
- the current event requestresponse
- the current event responsechain
- the remaining filter chainIOException
- if an IO error occurred in the filter processingPortletException
- if a portlet exception occurred in the filter processingJava Portlet 3.0 API Specification. See the Copyright and License provided with this distribution. Use is subject to license terms.