编程辅导 ISIT315, Spring 2020

//———————————————————————–
// This is written by a cool lecturer 😉
// SCIT, UOW
// ISIT315, Spring 2020

Copyright By PowCoder代写 加微信 powcoder

//———————————————————————–

package week5;

import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;

import org.apache.jena.query.Query;
import org.apache.jena.query.QueryExecution;
import org.apache.jena.query.QueryExecutionFactory;
import org.apache.jena.query.QueryFactory;
import org.apache.jena.query.QuerySolution;
import org.apache.jena.query.ResultSet;
import org.apache.jena.query.ResultSetFactory;
import org.apache.jena.query.ResultSetFormatter;
import org.apache.jena.query.ResultSetRewindable;
import org.apache.jena.rdf.model.Literal;
import org.apache.jena.rdf.model.Model;
import org.apache.jena.rdf.model.ModelFactory;
import org.apache.jena.riot.Lang;
import org.apache.jena.riot.RDFDataMgr;
import org.apache.jena.sparql.engine.http.QueryEngineHTTP;
import org.apache.jena.util.FileManager;

public class Lecture5 {

public static void main(String[] args) {
String PATH_DATA_LOCAL = System.getProperty(“user.dir”) + File.separator + “src” + File.separator + “main”
+ File.separator + “resources” + File.separator + “data” + File.separator + “temp.ttl”;
String PATH_DATA_REMOTE = “http://dig.csail.mit.edu/2008/webdav/timbl/foaf.rdf”;
String PATH_QUERY = System.getProperty(“user.dir”) + File.separator + “src” + File.separator + “main”
+ File.separator + “resources” + File.separator + “queries” + File.separator + “temp_Q.sparql”;
String ENDPOINT = “http://dbpedia.org/sparql”;
// select data source
String data = PATH_DATA_REMOTE;
// select query form file or directly enter
String query = QueryFactory.read(PATH_QUERY).toString();

Model model = ModelFactory.createDefaultModel();

// read data
model.read(data);
//model.write(System.out, “Turtle”);
// read query
executeQuery(query, false, model, “”);
executeQuery(query, true, null, ENDPOINT);
} catch (Exception ex) {
System.out.println(“Faild to load Data/Query: ” + ex.toString());

public static void executeQuery(String query, boolean remote, Model model, String endPoint) {

if (query.contains(“SELECT”)) {
if (remote)
select_remote(query, endPoint);
select_local(query, model);
} else if (query.contains(“CONSTRUCT”)) {
Model graph = construct_local(query, model);
select_local(“SELECT * {?s ?p ?o .}”, graph);
// Write a model in Turtle syntax, default style (pretty printed)
RDFDataMgr.write(System.out, graph, Lang.TURTLE);
} else if (query.contains(“ASK”)) {
System.out.println(ask_local(query, model));
} else if (query.contains(“DESCRIBE”)) {
Model graph = describe_local(query, model);
select_local(“SELECT * {?s ?p ?o .}”, graph);
// Write a model in Turtle syntax, default style (pretty printed)
RDFDataMgr.write(System.out, graph, Lang.TURTLE);

// ————————————————————————————–
public static ResultSet select_remote(String query_string, String ENDPOINT) {
ResultSet results = null;
Query query = QueryFactory.create(query_string);
QueryExecution qexec = QueryExecutionFactory.sparqlService(ENDPOINT, query);
results = qexec.execSelect();
} finally {
if (results != null)
ResultSetFormatter.out(System.out, results, query);
System.out.println(“no results were found!”);
qexec.close();
return results;

// —————————————————————————————
public static ResultSet select_local(String query_string, Model model) {
ResultSet results = null;
Query query = QueryFactory.create(query_string);
QueryExecution qexec = QueryExecutionFactory.create(query, model);
results = qexec.execSelect();
} finally {
if (results != null)
ResultSetFormatter.out(System.out, results, query);
System.out.println(“no results were found!”);
qexec.close();
return results;

// —————————————————————————————–
public static Model construct_local(String query_string, Model model) {
Model graph = null;
Query query = QueryFactory.create(query_string);
QueryExecution qexec = QueryExecutionFactory.create(query, model);
graph = qexec.execConstruct();
} finally {
qexec.close();
return graph;

// ——————————————————————————————
public static Boolean ask_local(String query_string, Model model) {
Boolean results = null;
Query query = QueryFactory.create(query_string);
QueryExecution qexec = QueryExecutionFactory.create(query, model);
results = qexec.execAsk();
} finally {
qexec.close();
return results;

// ——————————————————————————————
public static Model describe_local(String query_string, Model model) {
Model results = null;
Query query = QueryFactory.create(query_string);
QueryExecution qexec = QueryExecutionFactory.create(query, model);
results = qexec.execDescribe();
} finally {
qexec.close();
return results;

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