Revision: 1813
Author: [email protected]
Date: Fri Jan 8 08:23:04 2010
Log: Basic backend SPARQL query support (Issue 116)
http://code.google.com/p/simal/source/detail?r=1813
Added:
/trunk/uk.ac.osswatch.simal.core/src/main/java/uk/ac/osswatch/simal/model/jena/SparqlResult.java
/trunk/uk.ac.osswatch.simal.core/src/test/java/uk/ac/osswatch/simal/model
/trunk/uk.ac.osswatch.simal.core/src/test/java/uk/ac/osswatch/simal/model/jena
/trunk/uk.ac.osswatch.simal.core/src/test/java/uk/ac/osswatch/simal/model/jena/simal
/trunk/uk.ac.osswatch.simal.core/src/test/java/uk/ac/osswatch/simal/model/jena/simal/TestJenaSimalRepository.java
Modified:
/trunk/uk.ac.osswatch.simal.core
/trunk/uk.ac.osswatch.simal.core/src/main/java/uk/ac/osswatch/simal/model/jena/simal/JenaSimalRepository.java
=======================================
--- /dev/null
+++
/trunk/uk.ac.osswatch.simal.core/src/main/java/uk/ac/osswatch/simal/model/jena/SparqlResult.java
Fri Jan 8 08:23:04 2010
@@ -0,0 +1,81 @@
+/*
+ * Copyright 2010 University of Oxford
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package uk.ac.osswatch.simal.model.jena;
+
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.hp.hpl.jena.rdf.model.RDFNode;
+
+/**
+ * Holds the result of a SPARQL query in tabular form
+ * for easy display. This is meant as a transient data class
+ * to store a query result set for use at the front end.
+ * Exposes the list iterator, which makes the caller responsible
+ * for first adding all results before displaying results.
+ * Intended for single-threaded use because of ArrayLists.
+ *
+ * @author svanderwaal
+ *
+ */
+public class SparqlResult {
+ public static final Logger LOGGER = LoggerFactory
+ .getLogger(SparqlResult.class);
+
+ private List<String> varNames;
+
+ private List<List<RDFNode>> sparqlResults;
+
+ /**
+ * Create a new SparqlResult for given variable names.
+ * @param varNames
+ */
+ public SparqlResult(List<String> varNames) {
+ this.varNames = varNames;
+ this.sparqlResults = new ArrayList<List<RDFNode>>();
+ }
+
+ /**
+ * Add a result to the query result set. Corresponds to
+ * a row in a regular SQL result set.
+ * @param result
+ */
+ public void addResult(List<RDFNode> result) {
+ this.sparqlResults.add(result);
+ }
+
+ /**
+ * Return the variable names that are bound for this
+ * query result.
+ * @return
+ */
+ public List<String> getVarNames() {
+ return this.varNames;
+ }
+
+ /**
+ * Expose iterator to let caller iterate over the result.
+ * @return iterator
+ */
+ public Iterator<List<RDFNode>> getResultsIterator() {
+ return sparqlResults.iterator();
+ }
+
+}
=======================================
--- /dev/null
+++
/trunk/uk.ac.osswatch.simal.core/src/test/java/uk/ac/osswatch/simal/model/jena/simal/TestJenaSimalRepository.java
Fri Jan 8 08:23:04 2010
@@ -0,0 +1,99 @@
+/*
+ * Copyright 2010 University of Oxford
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package uk.ac.osswatch.simal.model.jena.simal;
+
+import static junit.framework.Assert.assertEquals;
+import static junit.framework.Assert.assertNull;
+import static junit.framework.Assert.assertNotNull;
+import static junit.framework.Assert.fail;
+
+import java.util.Iterator;
+import java.util.List;
+
+import org.junit.Test;
+
+import
uk.ac.osswatch.simal.integrationTest.model.repository.BaseRepositoryTest;
+import uk.ac.osswatch.simal.model.jena.SparqlResult;
+import uk.ac.osswatch.simal.rdf.ISimalRepository;
+import uk.ac.osswatch.simal.rdf.SimalRepositoryException;
+
+import com.hp.hpl.jena.rdf.model.RDFNode;
+
+/**
+ * Test Jena specific functionality of JenaSimalRepository.
+ *
+ * @author svanderwaal
+ *
+ */
+public class TestJenaSimalRepository extends BaseRepositoryTest {
+
+ private static final String QUERY_PREFIX = " PREFIX xsd:
<http://www.w3.org/2001/XMLSchema#> "
+ + " PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> "
+ + " PREFIX doap: <http://usefulinc.com/ns/doap#> "
+ + " PREFIX simal: <http://oss-watch.ac.uk/ns/0.2/simal#> ";
+
+ private static final String QUERY_ALL_PROJECTS = QUERY_PREFIX
+ + "SELECT DISTINCT ?project" + " WHERE "
+ + " { ?project rdf:type doap:Project ;" + " }";
+
+ private static final String QUERY_INVALID = QUERY_PREFIX + "SELECT *";
+
+ @Test
+ public void testSparqlQuery() {
+ SparqlResult projects;
+ String expectedVarName = "project";
+ int expectedNrProjects = 10;
+
+ try {
+ projects = getJenaSimalRepository().getSparqlQueryResult(
+ QUERY_ALL_PROJECTS);
+ List<String> actualVarNames = projects.getVarNames();
+ assertEquals(1, actualVarNames.size());
+ assertEquals(expectedVarName, actualVarNames.get(0));
+
+ Iterator<List<RDFNode>> projIter = projects.getResultsIterator();
+ int actualNrProjects =0;
+ while (projIter.hasNext()) {
+ List<RDFNode> curResult = projIter.next();
+ assertEquals(1, curResult.size());
+ assertNotNull(curResult.get(0));
+ actualNrProjects++;
+ }
+ assertEquals(expectedNrProjects, actualNrProjects);
+ } catch (SimalRepositoryException e) {
+ fail("Could not query repository");
+ }
+ }
+
+ @Test
+ public void testInvalidSparqlQuery() {
+ SparqlResult projects = null;
+ try {
+ projects =
getJenaSimalRepository().getSparqlQueryResult(QUERY_INVALID);
+ fail("Query was invalid so should fail without results.");
+ } catch (SimalRepositoryException e) {
+ assertNull("Query was invalid so should fail without results.",
projects);
+ }
+ }
+
+ private JenaSimalRepository getJenaSimalRepository() {
+ ISimalRepository repo = getRepository();
+ if (!(repo instanceof JenaSimalRepository)) {
+ fail("Configuration problem; testing Jena when repo is not of Jena
type");
+ }
+ return (JenaSimalRepository) repo;
+ }
+}
=======================================
---
/trunk/uk.ac.osswatch.simal.core/src/main/java/uk/ac/osswatch/simal/model/jena/simal/JenaSimalRepository.java
Tue Dec 15 16:31:12 2009
+++
/trunk/uk.ac.osswatch.simal.core/src/main/java/uk/ac/osswatch/simal/model/jena/simal/JenaSimalRepository.java
Fri Jan 8 08:23:04 2010
@@ -30,8 +30,10 @@
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;
+import java.util.ArrayList;
import java.util.HashSet;
import java.util.Iterator;
+import java.util.List;
import java.util.Random;
import java.util.Set;
@@ -64,6 +66,7 @@
import uk.ac.osswatch.simal.model.jena.Homepage;
import uk.ac.osswatch.simal.model.jena.Project;
import uk.ac.osswatch.simal.model.jena.Resource;
+import uk.ac.osswatch.simal.model.jena.SparqlResult;
import uk.ac.osswatch.simal.model.simal.SimalOntology;
import uk.ac.osswatch.simal.rdf.AbstractSimalRepository;
import uk.ac.osswatch.simal.rdf.ISimalRepository;
@@ -73,10 +76,18 @@
import com.hp.hpl.jena.db.DBConnection;
import com.hp.hpl.jena.db.IDBConnection;
+import com.hp.hpl.jena.query.Query;
+import com.hp.hpl.jena.query.QueryException;
+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.Model;
import com.hp.hpl.jena.rdf.model.ModelFactory;
import com.hp.hpl.jena.rdf.model.ModelMaker;
import com.hp.hpl.jena.rdf.model.Property;
+import com.hp.hpl.jena.rdf.model.RDFNode;
import com.hp.hpl.jena.rdf.model.Statement;
import com.hp.hpl.jena.rdf.model.StmtIterator;
import com.hp.hpl.jena.vocabulary.RDF;
@@ -265,6 +276,51 @@
return null;
}
}
+
+ /**
+ * Generic method for querying the RDF backend.
+ *
+ * @param queryStr
+ * valid SPARQL query
+ * @return
+ * @throws SimalRepositoryException
+ */
+ @SuppressWarnings("unchecked")
+ public SparqlResult getSparqlQueryResult(String queryStr)
+ throws SimalRepositoryException {
+ SparqlResult sparqlResult = null;
+ QueryExecution qe = null;
+
+ try {
+ Query query = QueryFactory.create(queryStr);
+ qe = QueryExecutionFactory.create(query, model);
+ ResultSet results = qe.execSelect();
+ sparqlResult = new SparqlResult(results.getResultVars());
+
+ while (results.hasNext()) {
+ QuerySolution soln = results.nextSolution();
+ List<RDFNode> result = new ArrayList<RDFNode>();
+ Iterator<Object> varNamesIter = soln.varNames();
+ while (varNamesIter.hasNext()) {
+ String varName = (String) varNamesIter.next();
+ result.add(soln.get(varName));
+ }
+ sparqlResult.addResult(result);
+ }
+
+ } catch (QueryException e) {
+ String message = "QueryException when trying to SPARQLquery with
query: "
+ + queryStr;
+ logger.warn(message + "; message: " + e.getMessage());
+ throw new SimalRepositoryException(message, e);
+ } finally {
+ if (qe != null) {
+ qe.close();
+ }
+ }
+
+ return sparqlResult;
+ }
/**
* @refactor should be moved to ProjectService class
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