急~~用Jena读RDF文件时，碰到了NullPointerException，在线等。

scbb 2012-09-10 04:10:35

求牛人看看~~

代码：



package pl.jena;



import java.io.FileNotFoundException;

import java.io.IOException;

import java.io.InputStream;



import com.hp.hpl.jena.ontology.OntModel;

import com.hp.hpl.jena.query.Query;

import com.hp.hpl.jena.query.QueryExecution;

import com.hp.hpl.jena.query.QueryExecutionFactory;

import com.hp.hpl.jena.query.QueryFactory;

import com.hp.hpl.jena.query.QuerySolution;

import com.hp.hpl.jena.query.ResultSet;

import com.hp.hpl.jena.rdf.model.ModelFactory;

import com.hp.hpl.jena.util.FileManager;



public class JenaSample {



	public static void main(String args[]) throws IOException {

		getVulnerabilityInfo("C:/jena/jvndb.rdf");

	}



	public static void getVulnerabilityInfo(String fileName) {

		InputStream in = null;

		try {

			OntModel ontModel = ModelFactory.createOntologyModel();



			in = FileManager.get().open(fileName);

			if (in == null) {

				throw new FileNotFoundException(fileName);

			}



			ontModel.read(in, ""); //这里报NullPointerException



			String queryString = "PREFIX rss:   <http://purl.org/rss/1.0/> "

					+ " SELECT ?item_title ?item_link" + " WHERE "

					+ "{ ?item rss:title ?item_title "

					+ " FILTER regex(?item_title, \"Android\", \"i\" ) ."

					+ "?item rss:link ?item_link }";

			

			Query query = QueryFactory.create(queryString);

			QueryExecution qe = QueryExecutionFactory.create(query, ontModel);

			ResultSet results = qe.execSelect();



			while (results.hasNext()) {

				QuerySolution qs = results.next();

				 System.out.println(qs.get("item_title"));

				 System.out.println(qs.get("item_link"));

			}



			// ResultSetFormatter.out(System.out, results, query);

			qe.close();



		} catch (Exception e) {

			e.printStackTrace();

		} finally {

			if (in != null) {

				try {

					in.close();

				} catch (IOException e) {

				}

			}

		}

	}



}