Closing the loop with a Java interface for rdfDB.

Hi,

I am happy to announce a Java interface to rdfDB and also an example
where RDF is drawn to and from a database.

Disclaimer:
To see it working, you'll have to accept reading some French...

I am now producing three complete RDF/RSS 1.0 channels with all the
articles available on XMLfr.

These channels are available at:
 
http://xmlfr.org/actualites/xmlfr/channel.rss10, 
http://xmlfr.org/actualites/decid/channel.rss10 and 
http://xmlfr.org/actualites/tech/channel.rss10. 

The articles are written using XMLNews-Story and have enough meta
information to generate (through a XSLT transformation) all the items
information that you see in these channels.

These 3 channels have been loaded into a rdfDB database which is queried
using the JrdfDB published on 4xt to generate dynamic pages available at
the same URIs than the one used for the taxonomy.

Some examples are:

http://xmlfr.org/index/object.title/RDF/
http://xmlfr.org/index/object.title/RSS/
http://xmlfr.org/index/person/Rael_Dornfest/
http://xmlfr.org/index/person/Dan_Connolly/

In the future, I plan to add more information on these pages which
include a list of all the articles mentioning the selected "object".

In the examples included on 4xt download section, I have also included
an example showing how RDF/RSS channels can be generated from the rdfDB:

input:  http://4xt.org/downloads/JrdfDB/2rss.in
xslt:   http://4xt.org/downloads/JrdfDB/2rss.xsl
output: http://4xt.org/downloads/JrdfDB/2rss.out

This example is closing the loop, showing how data taken from RSS
channels can be exported back as RSS channels.

I hope you'll enjoy it !

Eric

PS: many thanks to Guha for his rdfDB.
-- 
------------------------------------------------------------------------
Eric van der Vlist       Dyomedea                    http://dyomedea.com
http://xmlfr.org         http://4xt.org              http://ducotede.com
------------------------------------------------------------------------

attached mail follows:

Java interface for rdfDB 
A new Java interface for rdfDB is available on 4xt, allowing to send a 
request and get the results back in plain Java and/or from a XT  XSLT 
transformation. 
By Eric van der Vlist  , Dyomedea (vdv@dyomedea.com). 
--------------- 
Read this article online : 
(http://4xt.org/news/000919-0001.xml). 
--------------- 

RdfDB is "a simple, scalable, open-source database for RDF" developed 
by R.V. Guha  . 

This new interface allows querying the database using its query 
language and to get the results back row by row and column by column in 
plain Java and/or as a result tree fragment in a XT   XSLT 
transformation. 

It is currently used on XMLfr, where a full site summary has been 
loaded into rdfDB as three RSS 1.0 channel using the DC and taxonomy 
modules. 

These channels are available as 
http://xmlfr.org/actualites/xmlfr/channel.rss10, 
http://xmlfr.org/actualites/decid/channel.rss10 and 
http://xmlfr.org/actualites/tech/channel.rss10. 

The syntax used is a variant recently proposed by Edd Dumbill  on 
rss-dev. 

Dynamic pages are generated by a XT Servlet with a list of articles for 
each keyword. 

As an example, you can have a look at 
http://xmlfr.org/index/object.title/Java/, for instance, where you'll 
find a list of articles mentioning Java. 

The URIs of these pages are also used to identify the keywords in the 
taxonomy of the RSS channels. 

One of the examples provided in our download section (2rss) shows how 
specific RSS channels for a topic can easily be generated using the 
interface, allowing to close the loop: the rdfDB fed by RSS channels 
can generate RSS channels. 

Copyright Eric van der Vlist. 

--------------------------------------------------------- 
Generated by FormatedTextOutputHandler 4xt 
(http://4xt.org/downloads/examples/outputhandlers/formatedtext/).