My First Semantic Web Program
I have create my first slightly interesting, to me anyway, program that uses some semantic web technology. Of course I’ll look back on this in a year and cringe, but for now it represents my understanding of a small set of features from Jena and Pellet.
The basis for the program is an example program that is described in Hebler, Fischer et al’s book “Semantic Web Programming” (ISBN: 047041801X). The intent of the program is to load an ontology into three models, each running a different level of reasoner (RDF, RDFS and OWL) and output the resulting assertions (triples).
I made a couple of changes to the book’s sample’s approach. First I allow any supported input file format to be automatically loaded (you don’t have to tell the program what format is being used). Second, I report the actual differences between the models rather than just showing all the resulting triples.
As I worked on the code, which is currently housed in one uber-class (that’ll have to be refactored!), I realized that there will be lots of reusable “plumbing” code that comes with this type of work. Setting up models with various reasoners, loading ontologies, reporting triples, interfacing to triple stores, and so on will become nuisance code to write.
Libraries like Jena help, but they abstract at a low level. I want a semantic workbench that makes playing with the various libraries and frameworks easy. To that end I’ve created a Sourceforge project called “Semantic Workbench“.
I intend for the Semantic Workbench to provide a GUI environment for manipulating semantic web technologies. Developers and power users would be able to use such a tool to test ontologies, try various reasoners and validate queries. Developers could use the workbench’s source code to understand how to utilize frameworks like Jena or reasoner APIs like that of Pellet.
I invite other interested people to join the Sourceforge project. The project’s URL is: http://semanticwb.sourceforge.net/
On the data side, in order to have a rich semantic test data set to utilize, I’ve started an ontology that I hope to grow into an interesting example. I’m using the insurance industry as its basis. The rules around insurance and the variety of concepts should provide a rich set of classes, attributes and relationships for modeling. My first version of this example ontology is included with the sample program.
Finally, I’ve added a semantic web section to my website where I’ll maintain links to useful information I find as well as sample code or files that I think might be of interest to other developers. I’ve placed the sample program and ontology described earlier in this post on that page along with links to a variety of resources.
My site’s semantic web page’s URL is: http://monead.com/semantic/
The URL for the page describing the sample program is: http://monead.com/semantic/proj_diffinferencing.html