This example describes how to add/remove a set of triples over a named graph stored in an Oracle NoSQL Database.
import com.hp.hpl.jena.graph.*;
import com.hp.hpl.jena.query.*;
import com.hp.hpl.jena.rdf.model.Model;
import oracle.rdf.kv.client.jena.*;
public class Example1b {
public static void main(String[] args) throws Exception
{
String szStoreName = args[0];
String szHostName = args[1];
String szHostPort = args[2];
String szGraphName = args[3];
OracleNoSqlConnection conn
= OracleNoSqlConnection.createInstance(szStoreName,
szHostName,
szHostPort);
// This object will handle operations over the named graph
OracleGraphNoSql graph
= new OracleNamedGraphNoSql(szGraphName, conn);
// Clear the named graph including inferred triples
graph.clearRepository();
// Add triples
graph.add(Triple.create(Node.createURI("u:John"),
Node.createURI("u:parentOf"),
Node.createURI("u:Mary")));
graph.add(Triple.create(Node.createURI("u:Mary"),
Node.createURI("u:parentOf"),
Node.createURI("u:Jack")));
String queryString = " select ?x ?y WHERE {?x <u:parentOf> ?y}";
System.out.println("Execute query " + queryString);
Model model = new OracleModelNoSql(graph);
Query query = QueryFactory.create(queryString);
QueryExecution qexec = QueryExecutionFactory.create(query, model);
try {
ResultSet results = qexec.execSelect();
ResultSetFormatter.out(System.out, results, query);
}
finally {
qexec.close();
}
graph.delete(Triple.create(Node.createURI("u:John"),
Node.createURI("u:parentOf"),
Node.createURI("u:Mary")));
queryString = "select ?x ?y ?z WHERE {?x ?y ?z}";
System.out.println("Execute query " + queryString);
query = QueryFactory.create(queryString);
qexec = QueryExecutionFactory.create(query, model);
try {
ResultSet results = qexec.execSelect();
ResultSetFormatter.out(System.out, results, query);
}
finally {
qexec.close();
}
model.close();
conn.dispose();
}
}
The following are the commands to compile and run this example, as well as the expected output of the java command.
javac -classpath ./:./jena-core-2.7.4.jar:./jena-arq-2.9.4.jar: \
./sdordfnosqlclient.jar: ./kvclient.jar:./xercesImpl-2.10.0.jar: \
./slf4j-api-1.6.4.jar: ./slf4j-log4j12-1.6.4.jar:./log4j/1.2.16.jar: \
./jena-iri-0.9.4.jar:./xml-apis-1.4.01.jar Example1b.java
javac -classpath ./:./jena-core-2.7.4.jar:./jena-arq-2.9.4.jar: \
./sdordfnosqlclient.jar:./kvclient.jar:./xercesImpl-2.10.0.jar: \
./slf4j-api-1.6.4.jar:./slf4j-log4j12-1.6.4.jar:./log4j/1.2.16.jar: \
./jena-iri-0.9.4.jar:./xml-apis-1.4.01.jar Example1b <store_name> \
<host_name> <host_port> <graph_name>
Execute query select ?x ?y WHERE {?x <u:parentOf>?y}
-----------------------
| x | y |
=======================
| <u:Mary> | <u:Jack> |
| <u:John> | <u:Mary> |
-----------------------
Execute query select ?x ?y ?z WHERE {?x ?y ?z}
--------------------------------------
| x | y | z |
======================================
| <u:Mary> | <u:parentOf> | <u:Jack> |
--------------------------------------