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Re: sending xml response from servlet

From: Erik Bruchez <ebruchez@orbeon.com>
Date: Tue, 20 Feb 2007 22:00:20 +0100
Message-ID: <45DB6164.9000205@orbeon.com>
To: www-forms <www-forms@w3.org>

Leigh & all,

A correction: if you use the media type application/xml, which is the 
recommended media type for XML, i.e. you produce the header:

Content-Type: application/xml

then you must not add an encoding (charset) to that, because charset is 
defined for text media types. XML is actually not a text format in the 
usual sense, because of the XML declaration which can contain the 
encoding (and the default to UTF-8 if you don't have an XML declaration 
or no encoding in the declaration).

In short, this is what I recommend:

o Use application/xml

o If you want to specify an output encoding other than UTF-8, do it
   by setting the appropriate parameter on your XML serialization API.

o Always use the API to serialize XML to a binary stream rather than
   a text stream.

-Erik

Klotz, Leigh wrote:
> Iņaki,
> Whatever API you use, when you serialize, you will need to tell the 
> serializer what encoding to use, and specify that same value as the 
> charset in the HTTP response header.
> ISO-8859-1 will work, but you must tell JDOM to use it; otherwise it 
> will likely default to something else.
> XML that starts wtih <?xml version="1.0" ?> is UTF-8 by definition and 
> so is the default.
> So you really have 3 places to worry about but the XML API you use will 
> handle two of them (the XML declaration and the actual characters 
> themselves).
> You must make sure that the HTTP response header has the right value in it.
> If this isn't clear, please ask me.
> Leigh.
> 
> ------------------------------------------------------------------------
> *From:* www-forms-request@w3.org [mailto:www-forms-request@w3.org] *On 
> Behalf Of *Iņaki Salinas Bueno
> *Sent:* Monday, February 19, 2007 12:25 PM
> *To:* www-forms
> *Subject:* Re: sending xml response from servlet
> 
> Thanks all.
> 
> I did so many things and I had to change the code so many times trying 
> different forms to implement my application that I do not know which 
> code I have used. But I am very happy with the help you gave to me.
> 
> I tried to do it with JDOM library and I embroiled with it. I know why I 
> embroiled now (ignorance of how to use the Java language), I will try it 
> again later maybe.
> 
> Referring to the last comment of Leigh, I suppose that 
> charset=ISO-8859-1 works too. And thanks for your comments about 
> improving efficiency. It is not relevant for what I have to do but I 
> will consider it if efficiency turns relevant.
> 
> Regards,
> Iņaki
> 
> 
> 
> 2007/2/19, Erik Bruchez <ebruchez@orbeon.com <mailto:ebruchez@orbeon.com>>:
> 
> 
>     Iņaki,
> 
>     We have a very simple example in JSP in our CVS (scroll past the
>     tags...):
> 
>     http://cvs.forge.objectweb.org/cgi-bin/viewcvs.cgi/ops/orbeon/src/examples-jsp/flickr-search/service-search.jsp?rev=1.1&content-type=text/vnd.viewcvs-markup
>     <http://cvs.forge.objectweb.org/cgi-bin/viewcvs.cgi/ops/orbeon/src/examples-jsp/flickr-search/service-search.jsp?rev=1.1&content-type=text/vnd.viewcvs-markup>
> 
>     This example uses dom4j to read the submitted XML.
> 
>     BTW, I recommend you look at the eXist database instead of Xindice. This
>     will also allow you to have your forms directly talk with the database
>     using REST, instead of using a Java layer in the middle:
> 
>        http://exist.sourceforge.net/
> 
>     We have examples on our web site on how to access eXist from XForms,
>     including in our tutorial:
> 
>        http://www.orbeon.com/ops/doc/intro-tutorial
>        http://www.orbeon.com/ops/xforms-bookcast/
> 
>     Our Government Forms example also uses REST to directly talk to eXist:
> 
>        http://www.orbeon.com/ops/forms/
> 
>     I hope this helps,
> 
>     -Erik
> 
>     Iņaki Salinas Bueno wrote:
>      > Hello,
>      >
>      > Can someone recommend me a set of libraries that allow a servlet
>      > receive/send XML documents from/to xforms? I have found several
>      > libraries, but I don't know which is more adapted for what I want
>     to do.
>      >
>      > I'm using xforms in client side and a servlet for xindice (DB
>     manager)
>      > calls in server side.
>      >
>      > The servlet gets the xml document from xforms and add it in the DB
>      > correctly (I used a Xindice web application example and the tip
>     'Xforms
>      > tip: Accepting XForms data in Java
>      >
>     <http://www-128.ibm.com/developerworks/java/library/x-xformstipjava/index.html>'
>      > for its construction), but I don't know how can I get a XML document
>      > from DB and put it in the response object of the servlet.
>      >
>      > The example of the tip works with strings, so following it for the
>      > response I would have to take the XML document of the DB,
>     transform it
>      > into a string, and then send it. Cannot be the XML document sent as
>      > application/xml without transforming it into a string?
>      >
>      > Maybe questions are more java related than xforms, but they are
>      > working-with-xml related so I think that I can found help in this
>     forum.
>      >
>      > Thanks
>      > Iņaki
> 
> 
>     --
>     Orbeon Forms - Web Forms for the Enterprise Done the Right Way
>     http://www.orbeon.com/
> 
> 


-- 
Orbeon Forms - Web Forms for the Enterprise Done the Right Way
http://www.orbeon.com/
Received on Tuesday, 20 February 2007 21:00:38 GMT

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