Announcing Groovy SPARQL

As part of my on-going weekend hobby of looking at Groovy and the Semantic web technology stack, I've created a quick port of Groovy SQL support style operations into the land of SPARQL.  So, just like you can do Sql.eachRow(closure), you can now do Sparql.eachRow(closure)

Below is a Gist that shows the features of the relatively small API.  Note that this was also a dive into some Groovy 1.8 and Gradle, and was coded up this weekend inbetween BBQs using SpringSource Toolsuite 2.7.0M2 for the Groovy 1.8/Gradle support.

Other features to come include:

• Fluent DSL, leveraging Groovy 1.8 features 
• Pure Java "Templates" for Jena/SPARQL similar to JdbcTemplate/jmsTemplate in Spring
• Object marshalling and GORM / Spring Data support
• Sparql / RDF Builder -- still deciding if this is necessary or not, or if it'll fall naturally into the DSL
• Grails plug-in for the above
• Testing with triples stores Jena TDB, Stardog, and AllegroGraph being the first three

The code is up on Github here. 

	@Grab('com.hp.hpl.jena:jena:2.6.4')
	@Grab('com.hp.hpl.jena:arq:2.8.8')
	import groovy.sparql.Sparql
	// Can also take a Jena model as an argument
	def sparql = new Sparql("http://dbpedia.org/sparql")
	def query = """
	SELECT ?abstract
	WHERE {
	SERVICE <http://dbpedia.org/sparql> {
	<http://dbpedia.org/resource/Groovy_%28programming_language%29>
	<http://dbpedia.org/ontology/abstract>
	?abstract
	}
	} LIMIT 5
	"""
	sparql.eachRow query { row ->
	println row.abstract
	}
	/**
	* Also accept a map of binding parameters
	* Entries of URI type can be used in Subject/Predicate slots in the triple
	* Types of String are turned into Literals, so if you want literal URIs, use Strings
	*/
	def predicate = new URI("http://dbpedia.org/ontology/abstract")
	sparql.eachRow( query, [ uri:new URI("http://dbpedia.org/resource/Groovy_%28programming_language%29"), predicate:predicate], { row ->
	println row.abstract
	})
	/**
	* Also the map can accept an object, and find subject/predicate/object fields
	*/
	class GroovyWiki {
	def subject = new URI("http://dbpedia.org/resource/Groovy_%28programming_language%29")
	def predicate = new URI("http://dbpedia.org/ontology/abstract")
	}
	def obj = new GroovyWiki()
	def map = [groovy:obj]
	// note the form of the variables in the query is:
	// mapEntry name plus Subject, Predicate, or Object(not shown)
	query = """
	SELECT ?abstract
	WHERE {
	SERVICE <http://dbpedia.org/sparql> {
	?groovySubject ?groovyPredicate ?abstract
	}
	} LIMIT 5
	"""
	sparql = new Sparql("http://dbpedia.org/sparql")
	sparql.eachRow( query, map, { row ->
	println row.abstract
	})

view raw ExampleGroovySparql.groovy hosted with ❤ by GitHub

Enjoy!