[DL-Learner SVN] SF.net SVN: dl-learner:[3588] trunk/scripts/src/main/java/org/dllearner/ scripts/OxtractorHelper.java

[<jen...@us...>]

Revision: 3588
          http://dl-learner.svn.sourceforge.net/dl-learner/?rev=3588&view=rev
Author:   jenslehmann
Date:     2012-02-24 14:15:56 +0000 (Fri, 24 Feb 2012)
Log Message:
-----------
Oxtractor helper class

Added Paths:
-----------
    trunk/scripts/src/main/java/org/dllearner/scripts/OxtractorHelper.java

Added: trunk/scripts/src/main/java/org/dllearner/scripts/OxtractorHelper.java
===================================================================
--- trunk/scripts/src/main/java/org/dllearner/scripts/OxtractorHelper.java	                        (rev 0)
+++ trunk/scripts/src/main/java/org/dllearner/scripts/OxtractorHelper.java	2012-02-24 14:15:56 UTC (rev 3588)
@@ -0,0 +1,64 @@
+package org.dllearner.scripts;
+
+import java.util.Set;
+import java.util.TreeSet;
+
+import com.hp.hpl.jena.query.QuerySolution;
+import com.hp.hpl.jena.query.ResultSet;
+import com.hp.hpl.jena.sparql.engine.http.QueryEngineHTTP;
+
+public class OxtractorHelper {
+
+	private String endpoint = "http://live.dbpedia.org/sparql";
+	private String defaultGraph = "http://dbpedia.org";
+	
+	public OxtractorHelper(String endpoint) {
+		this(endpoint,null);
+	}
+	
+	public OxtractorHelper(String endpoint, String defaultGraph) {
+		this.endpoint = endpoint;
+		this.defaultGraph = defaultGraph;
+	}	
+	
+	public Set<String> getCategories(String keyword) {
+		String sparqlQuery = "SELECT DISTINCT ?cat { ?cat <http://purl.org/dc/terms/subject> ?subject . ?subject <http://www.w3.org/2000/01/rdf-schema#label> ?label . FILTER( bif:contains(?label, \""+keyword+"\" ) ) } LIMIT 100";
+		ResultSet rs = executeSelectQuery(sparqlQuery);
+		QuerySolution qs;
+		Set<String> categories = new TreeSet<String>();
+		while(rs.hasNext()){
+			qs = rs.next();
+			categories.add(qs.get("cat").toString());
+		}
+		return categories;
+	}
+	
+	public Set<String> getInstances(String category) {
+		String sparqlQuery = "SELECT ?instance { ?instance <http://purl.org/dc/terms/subject> <"+category+"> }";
+		ResultSet rs = executeSelectQuery(sparqlQuery);
+		QuerySolution qs;
+		Set<String> instances = new TreeSet<String>();
+		while(rs.hasNext()){
+			qs = rs.next();
+			instances.add(qs.get("instance").toString());
+		}
+		return instances;
+	}
+	
+	private ResultSet executeSelectQuery(String query) {
+		System.out.println("Sending query: " + query);
+		QueryEngineHTTP queryExecution = new QueryEngineHTTP(endpoint, query);
+		queryExecution.addDefaultGraph(defaultGraph);
+		return queryExecution.execSelect();
+	}	
+	
+	/**
+	 * @param args
+	 */
+	public static void main(String[] args) {
+		OxtractorHelper oh = new OxtractorHelper("http://live.dbpedia.org/sparql","http://dbpedia.org");
+		System.out.println(oh.getInstances("http://dbpedia.org/resource/Category:Cities_in_Saxony"));
+		System.out.println(oh.getCategories("room"));
+	}
+
+}

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