[DL-Learner SVN] SF.net SVN: dl-learner:[2214] trunk/src/dl-learner/org/dllearner

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

Revision: 2214
          http://dl-learner.svn.sourceforge.net/dl-learner/?rev=2214&view=rev
Author:   jenslehmann
Date:     2010-07-21 17:55:24 +0000 (Wed, 21 Jul 2010)

Log Message:
-----------
wrote small script to find SPARQL endpoints on the web

Modified Paths:
--------------
    trunk/src/dl-learner/org/dllearner/utilities/Files.java

Added Paths:
-----------
    trunk/src/dl-learner/org/dllearner/scripts/SparqlEndpointFinder.java

Added: trunk/src/dl-learner/org/dllearner/scripts/SparqlEndpointFinder.java
===================================================================
--- trunk/src/dl-learner/org/dllearner/scripts/SparqlEndpointFinder.java	                        (rev 0)
+++ trunk/src/dl-learner/org/dllearner/scripts/SparqlEndpointFinder.java	2010-07-21 17:55:24 UTC (rev 2214)
@@ -0,0 +1,83 @@
+/**
+ * Copyright (C) 2007-2010, Jens Lehmann
+ *
+ * This file is part of DL-Learner.
+ * 
+ * DL-Learner is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * DL-Learner is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+package org.dllearner.scripts;
+
+import java.io.File;
+import java.io.IOException;
+import java.net.MalformedURLException;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.net.URL;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import org.dllearner.utilities.Files;
+
+/**
+ * Tries to find some public SPARQL endpoints on the web.
+ * 
+ * @author Jens Lehmann
+ *
+ */
+public class SparqlEndpointFinder {
+
+	public static void main(String[] args) throws MalformedURLException, IOException {
+		SparqlEndpointFinder finder = new SparqlEndpointFinder();
+		System.out.println(finder.find());
+	}
+		
+	public List<String> find() throws MalformedURLException, IOException {
+		// the W3 wiki SPARQL endpoints page is often updated
+		String str = Files.readFile(new URL("http://esw.w3.org/index.php?title=SparqlEndpoints&action=edit"));
+		// typical wiki syntax: [http://dbtune.org/bbc/peel/sparql endpoint]
+		Pattern p = Pattern.compile("\\[(.+?) endpoint\\]");
+		Matcher m = p.matcher(str);
+		
+		List<String> endpoints = new LinkedList<String>();
+		while (m.find()) {
+			String endpoint = m.group(1);
+			if(SparqlEndpointFinder.validateEndpoint(endpoint)) {
+				endpoints.add(endpoint);
+			}
+		}	
+		
+		// TODO: finde more endpoints e.g. at http://www.freebase.com/view/user/bio2rdf/public/sparql
+		// or using voiD files
+		
+		// TODO: find graphs
+		
+		return endpoints;
+	}
+	
+	public static boolean validateEndpoint(String str) {
+//		URL url = null;
+		try {
+//			url = new URL(str);
+			new URL(str);
+		} catch (MalformedURLException e) {
+			return false;
+		}
+		// TODO: send example query to check whether endpoint is alive
+		return true;
+	}
+	
+}

Modified: trunk/src/dl-learner/org/dllearner/utilities/Files.java
===================================================================
--- trunk/src/dl-learner/org/dllearner/utilities/Files.java	2010-07-21 17:27:28 UTC (rev 2213)
+++ trunk/src/dl-learner/org/dllearner/utilities/Files.java	2010-07-21 17:55:24 UTC (rev 2214)
@@ -28,8 +28,10 @@
 import java.io.FileOutputStream;
 import java.io.FileReader;
 import java.io.IOException;
+import java.io.InputStreamReader;
 import java.io.ObjectInputStream;
 import java.io.ObjectOutputStream;
+import java.net.URL;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -43,6 +45,25 @@
 	public static boolean debug = false;
 
 	/**
+	 * Reads input from a URL and stores it in a string (only recommend for small files).
+	 * @param file URL of a file.
+	 * @return Contents of the file.
+	 * @throws IOException URL not accessible or content cannot be read for some reason.
+	 */
+	public static String readFile(URL file) throws IOException {
+		 BufferedReader in = new BufferedReader(new InputStreamReader(file.openStream()));
+
+		StringBuffer input = new StringBuffer();
+		String inputLine;
+		while ((inputLine = in.readLine()) != null) {
+		    input.append(inputLine + "\n");
+		}		    
+		in.close();
+			    
+		return input.toString();
+	}
+	
+	/**
 	 * Reads in a file.
 	 * 
 	 * @param file


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