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javardfkotlinjenaapache-jena

How can I get the value (object) of a Resource's property?

I have the following code, in which I find a resource by its e-mail.

val varn = "x"
val query = createQuery("""SELECT ?${varn}
                    WHERE { ?x  <http://www.w3.org/2001/vcard-rdf/3.0#EMAIL>  "${email}" }""")
val qexec = createQueryExecution(ds, query)
val rs = qexec.execSelect()
if (rs.hasNext()) {
    val solution = rs.nextSolution()
    val rec = solution[varn]
    // Here I need to find the value of the property FirstContactTime
}

Now I want to find out whether rec has a property FirstContactTime and if yes, its value.

I tried rec.model.listObjectsOfProperty(ds.defaultModel.createProperty(FirstContactTime)) but it doesn't return anything. The debugger says rec does have a property FirstContactTime.

Debugger

How can I get the value of FirstContactTime (2017-03-03T10:35:00Z) in my code?

Solution

  • Note that the property in the data is FirstContactDateTime not FirstContactTime.

    The SPARQL you're looking for is something like this --

    PREFIX  vcard:  <http://www.w3.org/2001/vcard-rdf/3.0#>
PREFIX     ex:  <http://example.com/schema/person/>

SELECT ?user ?email ?firstcontact
 WHERE
   {               ?x  vcard:EMAIL              ?email         .
      OPTIONAL  {  ?x  ex:firstContactDateTime  ?firstcontact  }
   }