この例では、SPARQL ASK問合せを示します。この例は、JohnがMaryの親であると推論するトリプルを挿入します。次に、JohnがMaryの親かどうかを検索します。
import com.hp.hpl.jena.graph.*; import com.hp.hpl.jena.query.*; import oracle.rdf.kv.client.jena.*; public class Example6 { public static void main(String[] args) throws Exception { String szStoreName = args[0]; String szHostName = args[1]; String szHostPort = args[2]; String szModelName = args[3]; // Create Oracle NoSQL connection OracleNoSqlConnection conn = OracleNoSqlConnection.createInstance(szStoreName, szHostName, szHostPort); // Create model from named graph OracleModelNoSql model = OracleModelNoSql.createOracleModelNoSql(szModelName, conn); // Clear model model.removeAll(); // Get graph from model OracleGraphNoSql graph = model.getGraph(); // Add triples graph.add(Triple.create(Node.createURI("u:John"), Node.createURI("u:parentOf"), Node.createURI("u:Mary"))); String szQuery = " ASK { <u:John> <u:parentOf> <u:Mary> } "; System.out.println("Execute ASK query " + szQuery); Query query = QueryFactory.create(szQuery) ; QueryExecution qexec = QueryExecutionFactory.create(query, model) ; boolean b = qexec.execAsk(); System.out.println("Ask result = " + ((b)?"TRUE":"FALSE")); // Close objects qexec.close(); model.close(); conn.dispose(); } }
この例をコンパイルして実行するコマンドと、想定されるJavaコマンドの出力は次のとおりです。
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 Example6.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 Example6 <store_name> \ <host_name> <host_port> <graph_name> Execute ASK query ASK { <u:John> <u:parentOf> <u:Mary> } Ask result = TRUE