# AGSparqlRDFLiterals.java

`package com.franz.agbase.examples;
import com.franz.agbase.*;
public class AGSparqlRDFLiterals {
/**
* Demonstrates basic of matching RDF literals in SPARQL
*
* @param args unused
* @throws AllegroGraphException
*/
public static void main(String[] args) throws AllegroGraphException {
// Connect to server, which must already be running.
AllegroGraphConnection ags = new AllegroGraphConnection();
try {
ags.enable();
} catch (Exception e) {
throw new AllegroGraphException("Server connection problem", e);
}
// Create fresh triple-store for this example.
AllegroGraph ts = ags.renew("sparql", AGPaths.TRIPLE_STORES);
// Register any namespaces
ts.registerNamespace("dt", "http://example.org/datatype#");
ts.registerNamespace("ns", "http://example.org/ns#");
ts.registerNamespace("xsd", "http://www.w3.org/2001/XMLSchema#");
// Add some data to the store
ts.addStatement("!ns:a","!ns:p", "!\"42\"^^xsd:integer");
URINode u = (URINode)ts.addPart("!xsd:integer");
AGUtils.showURI(u);
ts.addStatement("!ns:b","!ns:p",ts.createLiteral("42", u));
ts.addStatement("!ns:c","!ns:p",ts.createLiteral("42", ts.createURI("http://www.w3.org/2001/XMLSchema#integer")));
ts.addStatement("!ns:d","!ns:p",ts.createLiteral("42", ts.createURI("http://www.w3.org/2001/XMLSchema#int")));
ts.addStatement("!ns:x","!ns:p",ts.createLiteral("cat", "en"));
URINode v = (URINode)ts.addPart("!dt:specialDatatype");
AGUtils.showURI(v);
ts.addStatement("!ns:z","!ns:p",ts.createLiteral("abc",v));
ts.addStatement("!ns:z2","!ns:p", "!\"abc\"^^dt:specialDatatype");
// This query has no solution because "cat" is not the same
// RDF literal as "cat"@en
String query =
"SELECT ?v WHERE { ?v ?p \"cat\" }";
// Query the store and show the results
SPARQLQuery sq = new SPARQLQuery();
sq.setTripleStore(ts);
sq.setQuery(query);
AGSparqlSelect.doSparqlSelect(sq);
// Now with the language tag "cat"@en
query =
"SELECT ?v WHERE { ?v ?p \"cat\"@en }";
// Query the store and show the results
sq.setQuery(query);
AGSparqlSelect.doSparqlSelect(sq);
// Now with single quotes instead of escaped double quotes
query =
"SELECT ?v WHERE { ?v ?p 'cat'@en }";
// Query the store and show the results
sq.setQuery(query);
AGSparqlSelect.doSparqlSelect(sq);
// Integers in a SPARQL query indicate an RDF typed literal
// with the datatype xsd:integer. Note that this will not
// match literals of another datatype, e.g. xsd:int.
query =
"SELECT ?v WHERE { ?v ?p 42 }";
// Query the store and show the results
sq.setQuery(query);
AGSparqlSelect.doSparqlSelect(sq);
// The query processor does not have to have any understanding
// of the values in the space of the datatype. Because the
// lexical form and datatype IRI both match, the literal matches.
query =
"SELECT ?v WHERE { ?v ?p 'abc'^^<http://example.org/datatype#specialDatatype> }";
// Query the store and show the results
sq.setQuery(query);
AGSparqlSelect.doSparqlSelect(sq);
// Close the triple store and disconnect from the server.
ts.closeTripleStore();
ags.disable();
}
}
`

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