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Re: Using Jigsaw as proxy to another proxy ?

From: Yves Lafon <ylafon@w3.org>
Date: Tue, 25 May 1999 19:24:40 +0200 (MET DST)
To: rob sanders <rsanders@draper.com>
cc: "www-jigsaw@w3.org" <www-jigsaw@w3.org>
Message-ID: <Pine.GSO.4.10.9905251915250.111-100000@tarantula.inria.fr>
On Mon, 24 May 1999, rob sanders wrote:

> I have been trying to understand how to customize my proxy for about a
> week now. Trying to figure out how to proxy all URLs except one
> corresponding to a servlet on the proxy configured Jigsaw server.
> I tried modifying the lookup mechanism in ProxyFrame class.
> I tried adding a ErrorFilter class and modifying the ingoing filter
> class.

If you have a proxy reachable at http://myproxy.com:8008/ for example, 
you may still access http://myproxy.com:8008/Doc/ directly, as if it was
not a proxy. This may access what you want to do.
in your case calling directly http://myproxy.com:8008/servlet/myServlet
should work directly.

> example rule file. I think my file would be:
> -------------------------------------
> #Make all acess to local proxy
> * proxy http://localHost:8001/
> #Access my servlet URL directly
> localHost:8001/servlet/* direct
> -------------------------------------

Well, proxydispatcher rules have not this granularity (yet) and its
filtering scheme is based on hosts only.
* are not handled but are implicit
ex foo.org match *.foo.org also, but you can have a rule for foo.org and
one for bar.foo.org, this rule is more specific than foo.org so it will be
taken first.
There is no notions of path in it. We may do that later, if we manage to
find a regexp pattern that fits two goals (efficiency and... compatible
license ;) ).

> I've opened JigAdmin and don't see how to add ProxyDispatcher to the
> ProxyFrame. the ProxyDispatcher filter class did not show up in the list
> of options when I tried to add it. When I tried to type in the class
> name directly:
>     org.w3c.www.protocol.http.proxy.ProxyDispatcher
> I got the error message "invalid frame class".

That's normal, ProxyDispatcher is not a server side filter but a client
side filter. See the image in 5) of
and more information on the proxy property at

> I also don't see how to indicate to ProxyDispatcher where my rule file
> is once I figure out how to integrate it into the server.
> I looked in the http-server.prop file and did not see anything
> resembling a proxyDispatcher rule file entry. I'm not sure what I am
> supposed to manually edit in the prop file.

You should have a ProxyDispatcher property added after you set it. (and
used it once to initialize it). But it can be done directly by editing the
config file (see

> Questions:
> 1) will this approach allow my server to proxy all URLs except local
> servlets and instead locate and activate the local servlets on the proxy
> configured Jigsaw server?
> 2) should ProxyDispatcher filter appear in the list of available
> resources in JigAdmin?
> thanks,
> -rob

      /\          - Yves Lafon - World Wide Web Consortium - 
  /\ /  \        Architecture Domain - Jigsaw Activity Leader
 /  \    \/\    
/    \   /  \   http://www.w3.org/People/Lafon - ylafon@w3.org    
Received on Tuesday, 25 May 1999 13:24:45 UTC

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