Re: How to Call Servlets, CGIs on your server and other servers; Servlet Chaining

[Stefano Mazzocchi <st...@apache.org>]

Robin Green wrote:
> 
> A lot of people have asked about this recently. It's really SO SO simple
> (and it's going in the new FAQ which is effectively a rewrite).
> 
> Unfortunately the 'answer' (or lack thereof) given in the current FAQ about
> "servlet chaining" is either very misleading or just plain wrong, I don't
> know which. Stefano?
> 
> What you DON'T do is use ProducerFromRequest - that's a security risk, as
> noted in the recent Security Advisory which I can email to anyone who wants
> it (it's also in the mail archives).
> 
> [A]. If the servlet or whatever you're calling returns XML, you can just do
> this: (If not see [B] below).
> 
> 1. Get the latest Cocoon from xml.apache.org/from-cvs or just from CVS
> directly. 1.7.4 and below have a bug which prevents this from working.
> 
> 2. Make an XSP page like this:
> 
> <?cocoon-process type="xsp"?>
> <xsp:page xmlns:xsp="http://www.apache.org/1999/XSP/Core"
>            xmlns:util="http://www.apache.org/1999/XSP/Util">
> <page>
>   <util:include-uri href="http://myserver.com/servlets/foo"/>
> </page>
> </xsp:page>
> 
> To build the URL dynamically just do something like this (if I remember
> correctly):
> 
> <util:include-uri>
> <util:href><xsp:expr>"http://myserver.com/servlets/foo?x=" + request.
> getParameter ("foo")</xsp:expr></util:href>
> </util:include-uri>
> 
> To include static XML files you can even use <util:include-file> (which is
> faster), but only if the file is on the filesystem(s) of your server. There
> are other options like XInclude and XML entities, but these should work
> fine.
> 
> [B] To get data from non-XML sources, just do like in any Java program:
> 
> Object content = new URL ("http://myserver.com/foobar").getContent ();
> 
> or openStream(), or whatever is most appropriate (inside a Producer or
> preferably an XSP page). Read the Javadocs for Java - it pays dividends!
> 
> To include static non-XML files which exist on your own server, it's faster
> to just do as A above but replace util:include-uri href= with
> util:get-file-contents name=

Yes, your answer is much better than the one in the FAQ... I think we
should update it.

-- 
Stefano Mazzocchi      One must still have chaos in oneself to be
                          able to give birth to a dancing star.
<st...@apache.org>                             Friedrich Nietzsche
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