Raw

That's Descriptions of Runtime Klasses. Some simple Java for getting RDF out of code trees.

The RDF can be used to generate class diagrams, like this:

An interesting aspect of the Web Beep project is processor pipelines. To optimize things I needed to play with parameters easily so wound up building a system interface covering the processors and pipelines. As it stand in the source now, the configuration is set up from Java structures. But to see what the configuration is, a recursive toString() on the Java structures yields a fairly structured text description of the configuration (there's an example on the How It Works page).

This led me to think that if such descriptions could be used to describe existing configurations, they could also be used to set up those configurations. The format's ad hoc, so first it made sense to look at using something standard. The processor pipelines are essentially graphs (with annotations) so RDF was naturally the hammer I chose. The general processors/pipelines model is encoded (better word?) in the Java class structure, so if I could get that in RDF it'd be a good start. It's general-purpose stuff so I've split it off as a separate project at github and given it a silly name.

This kind of thing's been done before, in fact I'm hoping to incorporate David Huynh's doclet (for use with Javadoc to generate RDF) as well in the near future. But that approach gets its data 'statically' from the source, whereas the parameters at runtime are important for Web Beep's processors etc. I've made a start on the write-up with the code (ermm, Javadoc's todo :), but one key thing is just using a describe() method in the kind of places you might use a toString(). It should return a snippet of Turtle-syntax RDF describing the object in which it appears. I've also made a start on some easy-to-use utility methods that use reflection to extract a description of objects which doesn't rely on them having a describe() method, bit of a lighter touch.

As a sanity check on the generated RDF I made a (pretty trivial) SPARQL query with XSLT transform to GraphViz dot format, the result of which can be used (with straightforward command-line tools) to generate images like the one above. [I remembered half way through that Redland's rapper utility can output dot format, but that's RDFy (see screenshot) and I'm after something much more app-specific.] There's a little script which shows how the image was arrived at.