org.w3c.jigsaw.http
Interface HTTPFilter

public interface HTTPFilter

Method Summary

Reply	exceptionFilter(Request request, ProtocolException ex, HTTPFilter[] filters, int fidx)
Reply	ingoingFilter(Request request, HTTPFilter[] filters, int fidx) The filter's ingoing method is called before any request processing is done by the target resource.
boolean	lookup(LookupState ls, LookupResult lr) The lookup stage filtering.
Reply	outgoingFilter(Request request, Reply reply, HTTPFilter[] filters, int fidx) The filter's outgoing method is called once the target resource has computed a reply.
java.io.OutputStream	outputFilter(Request request, Reply reply, java.io.OutputStream output)

Method Detail

lookup

boolean lookup(LookupState ls,
               LookupResult lr)
               throws ProtocolException

The lookup stage filtering. This filter is invoked during lookup, it can cancel the lookup operation in progress, by either throwing an exception (in case of error), or by returning true, in which case, the filter has perform the whole lookup operation itself.

Parameters:

ls - The current lookup state, describing the state of the lookup operation in progress.

lr - The current lookup result, describing the already computed part of the lookup operation.

Returns:

A boolean, true if lookup has been completed by the filter, and nothing else need to be done to complete it. Otherwise lookup should continue normally, and the filter returns false.

Throws:

ProtocolException - If some error occurs, and the whole lookup operation cannot be continued normally.

ingoingFilter

Reply ingoingFilter(Request request,
                    HTTPFilter[] filters,
                    int fidx)
                    throws ProtocolException

The filter's ingoing method is called before any request processing is done by the target resource.

This method can (if able) compute the whole request's reply, and return it. If processing should continue normally, then the filter must return null.

If a filter's ingoingFilter method gets called, then it is guaranteed that either its outgoingFilter method or its exceptionFilter method gets called.

Parameters:

request - The request being processed.

filters - The whole array of filters to be applied before actually continuing the process.

fidx - The index in the above array of the filter being called.

Returns:

A Reply instance, if the filter knows how to compute it, or null if the request processing should continue normally.

Throws:

ProtocolException - If the filter fails.

outgoingFilter

Reply outgoingFilter(Request request,
                     Reply reply,
                     HTTPFilter[] filters,
                     int fidx)
                     throws ProtocolException

The filter's outgoing method is called once the target resource has computed a reply.

This method can return a Reply instance, in which case, the processing should be aborted, and the returned reply should be emited back to the client. Otherwise, if the filter returns null the processing continues normally.

Parameters:

request - The request being processed.

reply - The original reply, as emited by the target resource, and which has already been processed by the first filters.

filters - The whole array of filters to be applied before actually continuing the process.

fidx - The index in the above array of the filter being called.

Throws:

ProtocolException - If the filter fails.

outputFilter

java.io.OutputStream outputFilter(Request request,
                                  Reply reply,
                                  java.io.OutputStream output)
                                  throws java.io.IOException

Throws:

java.io.IOException

exceptionFilter

Reply exceptionFilter(Request request,
                      ProtocolException ex,
                      HTTPFilter[] filters,
                      int fidx)

Parameters:

request - The request being processed.

ex - The exception that occured during processing the request. and which has already been processed by the first filters.

filters - The whole array of filters to be applied before actually continuing the process.

fidx - The index in the above array of the filter being called.