[graphl-cvs] graphl/src/org/mediavirus/graphl/graph/rdf RDFGraph.java

[Flo L. <fl...@us...>]

Update of /cvsroot/graphl/graphl/src/org/mediavirus/graphl/graph/rdf
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv24484/src/org/mediavirus/graphl/graph/rdf

Modified Files:
	RDFGraph.java 
Log Message:
- FEATURE: new command line flag to start "navigator" thread to zoom & pan in the graph
- CODE: loading graphs returns URL[] with all loaded (+included) files
- CODE: dynamically adding config-file + all included files to default filter
- DOC: extended user guide


Index: RDFGraph.java
===================================================================
RCS file: /cvsroot/graphl/graphl/src/org/mediavirus/graphl/graph/rdf/RDFGraph.java,v
retrieving revision 1.12
retrieving revision 1.13
diff -C2 -d -r1.12 -r1.13
*** RDFGraph.java	7 Sep 2005 12:29:55 -0000	1.12
--- RDFGraph.java	14 Dec 2005 12:45:08 -0000	1.13
***************
*** 14,17 ****
--- 14,18 ----
  import java.net.MalformedURLException;
  import java.net.URL;
+ import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Collections;
***************
*** 36,421 ****
   */
  public class RDFGraph extends DefaultGraph implements RDFConsumer {
!     
!     private static final boolean DEBUG = false;
!     
      boolean dirty = false;
!     
      Hashtable allNodes = new Hashtable();
!     
      URL loadingURL = null;
      Node sourceNode = null;
!     
      private int loadCount = 0;
  
      private float loadAlpha = 0.1f;
-     
- 	public RDFNode getNodeById(String id){
- 		return (RDFNode)allNodes.get(id);
- 	}
- 	
- 	public static void writeToRDF(Graph graph, OutputStream out, String baseURL) throws IOException {
- 		RDFWriter writer = new RDFWriter();
- 		
- 		// TODO (2) use vocabularies from config for prefix resolution
- 		writer.addNamespacePrefix("graphl",NS.graphl);
- 		writer.addNamespacePrefix("foaf","http://xmlns.com/foaf/0.1/");
- 		writer.addNamespacePrefix("rdf","http://www.w3.org/1999/02/22-rdf-syntax-ns#");
- 		writer.addNamespacePrefix("rdfs","http://www.w3.org/2000/01/rdf-schema#");
- 		writer.addNamespacePrefix("owl","http://www.w3.org/2002/07/owl#");
- 		writer.addNamespacePrefix("map","http://fabl.net/vocabularies/geography/map/1.1/");
- 		writer.addNamespacePrefix("geo","http://www.w3.org/2003/01/geo/wgs84_pos#");
- 		writer.addNamespacePrefix("dc","http://purl.org/dc/elements/1.1/");
- 		writer.addNamespacePrefix("foo","http://www.mediavirus.org/foo#");
- 		writer.addNamespacePrefix("vs","http://www.w3.org/2003/06/sw-vocab-status/ns#");
- 		writer.addNamespacePrefix("wot","http://xmlns.com/wot/0.1/");
  
! 		writer.prepareNamespaceCollection();
! 		
! 		writer.collectNamespace(NS.graphl);
! 		writer.collectNamespace("http://xmlns.com/foaf/0.1/");
! 		writer.collectNamespace("http://www.w3.org/1999/02/22-rdf-syntax-ns#");
! 		writer.collectNamespace("http://www.w3.org/2000/01/rdf-schema#");
! 		writer.collectNamespace("http://www.w3.org/2002/07/owl#");
! 		writer.collectNamespace("http://fabl.net/vocabularies/geography/map/1.1/");
! 		writer.collectNamespace("http://www.w3.org/2003/01/geo/wgs84_pos#");
! 		writer.collectNamespace("http://purl.org/dc/elements/1.1/");
! 		writer.collectNamespace("http://www.mediavirus.org/foo#");
! 		writer.collectNamespace("http://www.w3.org/2003/06/sw-vocab-status/ns#");
! 		writer.collectNamespace("http://xmlns.com/wot/0.1/");
  
! 		OutputStreamWriter owriter = new OutputStreamWriter(out);
! 		writer.startSerialization(owriter,"","","UTF-8");
! 		writer.startRDFContents();
! 				
! 		List allNodes = graph.getNodes();
! 		List allEdges = graph.getEdges();
! 		
! 		for (Iterator iter = allNodes.iterator(); iter.hasNext();) {
! 			Node node = (Node) iter.next();
! 			
! 			String id = node.getId();
! 			if ((baseURL != null) && (id.startsWith(baseURL)) && (id.lastIndexOf('#')>-1)) {
! 				id = id.substring(id.lastIndexOf('#'));
! 			}
! 			
! 			for (Iterator attrs = node.getProperties().keySet().iterator(); attrs.hasNext();) {
! 				String attr = (String) attrs.next();
! 				writer.writeStatement(id, attr, node.getProperty(attr), null, null, true);
! 			}
! 			List nodeEdges = node.getEdgesFrom();
! 			for (Iterator edgeIter = nodeEdges.iterator(); edgeIter.hasNext();) {
! 				Edge edge = (Edge) edgeIter.next();
! 				// TODO (3) this would be a reason to have a FilteredNode class that returns only filtered edges... 
! 				if (allEdges.contains(edge)) {
! 					String toId = edge.getTo().getId();
! 					if ((baseURL != null) && (toId.startsWith(baseURL)) && (toId.lastIndexOf('#')>-1)) {
! 						toId = toId.substring(toId.lastIndexOf('#'));
! 					}
! 					writer.writeStatement(id, edge.getType(), toId, null, null, false);
! 				}
! 			}
! 		}
! 		
! 		writer.finishRDFContents();
! 		writer.cleanUp();
! 		
! 	}
  
! 	public void writeToRDF(OutputStream out, String baseURL) throws IOException {
! 		writeToRDF(this, out, baseURL);
! 	}
! 	
! 	public synchronized void readFromFile(String filename) throws IOException {
! 		System.out.println("reading file " + filename);
! 		File f = new File(filename);
! 		try {
! 			loadingURL = new URL("file:///" + f.getAbsolutePath());
! 		}
! 		catch (MalformedURLException e) {}
! 		
! 		sourceNode = getNodeOrNew(loadingURL.toString());
  
- 		if (sourceNode.getNeighbours(NS.graphl + "definedIn", true).size() == 0) {
- 			Edge edge = createEdge(sourceNode, sourceNode);
- 			edge.setSource(NS.graphl + "SYSTEM");
- 			edge.setType(NS.graphl + "definedIn");
- 		}
- 		
- 		InputSource input = new InputSource(new FileReader(f));
- 		input.setSystemId("");
- 		readGraph(input);
- 		
- 		loadingURL = null;
- 		sourceNode = null;
- 	}
- 	
- 	public synchronized void readFromURL(URL url){
- 		
- 		loadingURL = url;
- 		sourceNode = getNodeOrNew(loadingURL.toString());
- 		
- 		if (sourceNode.getNeighbours(NS.graphl + "definedIn", true).size() == 0) {
- 			Edge edge = createEdge(sourceNode, sourceNode);
- 			edge.setSource(NS.graphl + "SYSTEM");
- 			edge.setType(NS.graphl + "definedIn");
- 		}
- 		
- 	    InputSource input;
          try {
              input = new InputSource(url.openConnection().getInputStream());
              input.setSystemId(url.toString());
              readGraph(input);
          }
!         catch (IOException e) {
              e.printStackTrace();
          }
  
! 		loadingURL = null;
! 		sourceNode = null;
! }
! 	
! 	public synchronized void readGraph(InputSource input) {
! 		RDFParser parser = new RDFParser();
! 	    loading = true;
          try {
!     		parser.parse(input,this);
          }
- 		catch (Exception e) {
- 			e.printStackTrace();
- 		}		
- 		loading = false;
- 		resetDirty();
- 		fireGraphContentsChanged();	    
- 	}
  
  
! 	/**
! 	 * @see edu.unika.aifb.rdf.api.syntax.RDFConsumer#startModel(java.lang.String)
! 	 */
! 	public void startModel(String physicalURI) throws SAXException {
! 		if (DEBUG) System.out.println("RDF: startModel");
! 	}
  
  
! 	/**
! 	 * @see edu.unika.aifb.rdf.api.syntax.RDFConsumer#endModel()
! 	 */
! 	public void endModel() throws SAXException {
! 	    if (DEBUG) System.out.println("RDF: endModel");
! 	}
  
  
! 	/**
! 	 * @see edu.unika.aifb.rdf.api.syntax.RDFConsumer#statementWithResourceValue(java.lang.String, java.lang.String, java.lang.String)
! 	 */
! 	public void statementWithResourceValue(String subject, String predicate, String object) throws SAXException {
! 		//if (predicate.equals(NS.graphl + "connectedTo")) {
! 			// get / create node with label subject
! 		
! 		if (loadingURL != null) {
! 			try {
! 				subject = new URL(loadingURL, subject).toString();
! 			}
! 			catch (MalformedURLException muex) {
! 				// do nothing
! 			}
! 			try {
! 				object = new URL(loadingURL, object).toString();
! 			}
! 			catch (MalformedURLException muex) {
! 				// do nothing
! 			}
! 		}
! 		
! 		Node snode;
! 		Node onode;
! 		try {
! 		    snode = getNodeOrNew(subject);
! 		    onode = getNodeOrNew(object);
  
! 			// get / create connection
! 			List edges = snode.getEdgesFrom();
! 			RDFEdge edge = null;
! 			boolean exists = false;
! 			
! 			for (Iterator iter = edges.iterator(); iter.hasNext();) {
! 				edge = (RDFEdge) iter.next();
! 				if ((edge.getTo() == onode) && (edge.getType().equals(predicate))) {
! 					exists = true;
! 					break;
! 				}
! 			}
! 			
! 			if (!exists) {
! 				edge = new RDFEdge(snode,onode);
! 				edge.setType(predicate);
! 				edge.setSource(loadingURL.toString());
! 				addElements(null, Collections.singleton(edge));
! 				if (DEBUG) System.out.println("created edge " + subject + ", " + predicate + ", " + object);
! 				
! 				if (predicate.equals("http://www.w3.org/2002/07/owl#imports")) {
! 					try {
! 						URL oldBase = loadingURL;
! 						Node oldSource = sourceNode;
! 						URL importURL = new URL(loadingURL, object);
! 						System.out.println("importing " + importURL.toString() + " ... ");
! 						readFromURL(importURL);
! 						// restore original base url
! 						loadingURL = oldBase;
! 						sourceNode = oldSource;
! 					}
! 					catch (MalformedURLException muex) {
! 						System.out.println("Error importing " + object);
! 					}
! 				}
! 			}
! 		}
! 	    catch (Exception ex) {
! 	        if (DEBUG) System.out.println("Error while reading triple: " + subject + ", " + predicate + ", " + object);
! 			//ex.printStackTrace();
! 	    }
! 			
! 	
  
! 	}
  
! 	public Node getNodeOrNew(String uri){
! 		RDFNode node = getNodeById(uri);
! 		if (node == null){
! 			node = new RDFNode(this, uri);
! 			float r = 20 + loadCount;
! 			loadAlpha += 30/r;
! 			node.setCenter(r*Math.sin(loadAlpha), r*Math.cos(loadAlpha));
! 			loadCount++;
! 			addElements(Collections.singleton(node), null);
! 			if (DEBUG) System.out.println("created node " + uri);
! 		}
! 		if (sourceNode != null) {
! 			boolean found = false;
! 			for (Iterator i = node.getNeighbours(NS.graphl + "definedIn", true).iterator(); i.hasNext();) {
! 				Node source = (Node) i.next();
! 				if (source.equals(sourceNode)) {
! 					found = true;
! 					break;
! 				}
! 			}
! 			if (!found) {
! 				Edge edge = createEdge(node, sourceNode);
! 				edge.setSource(NS.graphl + "SYSTEM");
! 				edge.setType(NS.graphl + "definedIn");
! 			}
! 		}
! 		return node;
! 	}
! 	
! 	public Node createNode() {
! 		RDFNode node = new RDFNode(this);
! 		addElements(Collections.singleton(node), null);
! 		return node;
! 	}
  
! 	public Edge createEdge(Node from, Node to) {
! 		RDFEdge edge = new RDFEdge(from, to);
! 		if (loadingURL != null) {
! 			edge.setSource(loadingURL.toString());
! 		}
! 		else {
! 			edge.setSource(NS.graphl + "USER");
! 		}
! 		addElements(null, Collections.singleton(edge));
! 		return edge;
! 	}
  
! 	/**
! 	 * @see edu.unika.aifb.rdf.api.syntax.RDFConsumer#statementWithLiteralValue(java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.String)
! 	 */
! 	public void statementWithLiteralValue(String subject, String predicate, String object, String language, String datatype) throws SAXException {
! 		
! 		// get absolute URL for subject
! 		if (loadingURL != null) {
! 			try {
! 				subject = new URL(loadingURL, subject).toString();
! 			}
! 			catch (MalformedURLException muex) {
! 				// do nothing
! 			}
! 		}
! 		
! 		Node snode;
! 		try {
! 		    snode = getNodeOrNew(subject);
! 		    snode.setProperty(predicate, object);
! 		    if (DEBUG) System.out.println("created property " + subject + ", " + predicate + ", " + object);
! 		}
! 	    catch (Exception ex) {
! 	        if (DEBUG) System.out.println("Error while reading triple: " + subject + ", " + predicate + ", " + object);
! 		}
! 	}
  
  
! 	/**
! 	 * @see edu.unika.aifb.rdf.api.syntax.RDFConsumer#logicalURI(java.lang.String)
! 	 */
! 	public void logicalURI(String logicalURI) throws SAXException {
! 	    if (DEBUG) System.out.println("RDF: logicalURI: " + logicalURI);
! 	}
  
  
! 	/**
! 	 * @see edu.unika.aifb.rdf.api.syntax.RDFConsumer#includeModel(java.lang.String, java.lang.String)
! 	 */
! 	public void includeModel(String logicalURI, String physicalURI) throws SAXException {
! 	    if (DEBUG) System.out.println("RDF: includeModel: " + logicalURI + ", " + physicalURI);
! 	}
  
  
- 	/**
- 	 * @see edu.unika.aifb.rdf.api.syntax.RDFConsumer#addModelAttribte(java.lang.String, java.lang.String)
- 	 */
- 	public void addModelAttribte(String key, String value) throws SAXException {
- 	    if (DEBUG) System.out.println("RDF: addModelAttribte" + key + ", " + value);
- 	}
- 	
      /**
       * @return Returns the dirty flag.
       */
      public boolean isDirty() {
          return dirty;
      }
!     
      /**
       * @param dirty New value for dirty flag.
       */
      public void setDirty(boolean dirty) {
          this.dirty = dirty;
      }
!     
      public void setDirty() {
          setDirty(true);
      }
!     
      public void resetDirty() {
          setDirty(false);
      }
!     
      /*
       * Overrides @see de.fzi.wim.guibase.graphview.graph.DefaultGraph#addElements(java.util.Collection, java.util.Collection)
       */
      public synchronized void addElements(Collection nodes, Collection edges) {
          setDirty();
          super.addElements(nodes, edges);
!         
          if (nodes != null) {
!             for (Iterator iter = nodes.iterator(); iter.hasNext();){
! 	            RDFNode node = (RDFNode) iter.next();
! 	            allNodes.put(node.getId(), node);
              }
          }
      }
!     
      /*
       * Overrides @see de.fzi.wim.guibase.graphview.graph.DefaultGraph#clear()
       */
      public synchronized void clear() {
          setDirty();
          allNodes.clear();
--- 37,450 ----
   */
  public class RDFGraph extends DefaultGraph implements RDFConsumer {
! 
!     public static boolean DEBUG = false;
! 
      boolean dirty = false;
! 
      Hashtable allNodes = new Hashtable();
! 
      URL loadingURL = null;
+ 
+     List<URL> loadingURLs = null;
+ 
      Node sourceNode = null;
! 
      private int loadCount = 0;
  
      private float loadAlpha = 0.1f;
  
!     public RDFNode getNodeById(String id) {
  
!         return (RDFNode) allNodes.get(id);
!     }
  
!     public static void writeToRDF(Graph graph, OutputStream out, String baseURL) throws IOException {
! 
!         RDFWriter writer = new RDFWriter();
! 
!         // TODO (2) use vocabularies from config for prefix resolution
!         writer.addNamespacePrefix("graphl", NS.graphl);
!         writer.addNamespacePrefix("foaf", "http://xmlns.com/foaf/0.1/");
!         writer.addNamespacePrefix("rdf", "http://www.w3.org/1999/02/22-rdf-syntax-ns#");
!         writer.addNamespacePrefix("rdfs", "http://www.w3.org/2000/01/rdf-schema#");
!         writer.addNamespacePrefix("owl", "http://www.w3.org/2002/07/owl#");
!         writer.addNamespacePrefix("map", "http://fabl.net/vocabularies/geography/map/1.1/");
!         writer.addNamespacePrefix("geo", "http://www.w3.org/2003/01/geo/wgs84_pos#");
!         writer.addNamespacePrefix("dc", "http://purl.org/dc/elements/1.1/");
!         writer.addNamespacePrefix("foo", "http://www.mediavirus.org/foo#");
!         writer.addNamespacePrefix("vs", "http://www.w3.org/2003/06/sw-vocab-status/ns#");
!         writer.addNamespacePrefix("wot", "http://xmlns.com/wot/0.1/");
! 
!         writer.prepareNamespaceCollection();
! 
!         writer.collectNamespace(NS.graphl);
!         writer.collectNamespace("http://xmlns.com/foaf/0.1/");
!         writer.collectNamespace("http://www.w3.org/1999/02/22-rdf-syntax-ns#");
!         writer.collectNamespace("http://www.w3.org/2000/01/rdf-schema#");
!         writer.collectNamespace("http://www.w3.org/2002/07/owl#");
!         writer.collectNamespace("http://fabl.net/vocabularies/geography/map/1.1/");
!         writer.collectNamespace("http://www.w3.org/2003/01/geo/wgs84_pos#");
!         writer.collectNamespace("http://purl.org/dc/elements/1.1/");
!         writer.collectNamespace("http://www.mediavirus.org/foo#");
!         writer.collectNamespace("http://www.w3.org/2003/06/sw-vocab-status/ns#");
!         writer.collectNamespace("http://xmlns.com/wot/0.1/");
! 
!         OutputStreamWriter owriter = new OutputStreamWriter(out);
!         writer.startSerialization(owriter, "", "", "UTF-8");
!         writer.startRDFContents();
! 
!         List allNodes = graph.getNodes();
!         List allEdges = graph.getEdges();
! 
!         for (Iterator iter = allNodes.iterator(); iter.hasNext();) {
!             Node node = (Node) iter.next();
! 
!             String id = node.getId();
!             if ((baseURL != null) && (id.startsWith(baseURL)) && (id.lastIndexOf('#') > -1)) {
!                 id = id.substring(id.lastIndexOf('#'));
!             }
! 
!             for (Iterator attrs = node.getProperties().keySet().iterator(); attrs.hasNext();) {
!                 String attr = (String) attrs.next();
!                 writer.writeStatement(id, attr, node.getProperty(attr), null, null, true);
!             }
!             List nodeEdges = node.getEdgesFrom();
!             for (Iterator edgeIter = nodeEdges.iterator(); edgeIter.hasNext();) {
!                 Edge edge = (Edge) edgeIter.next();
!                 // TODO (3) this would be a reason to have a FilteredNode class that returns only filtered edges... 
!                 if (allEdges.contains(edge)) {
!                     String toId = edge.getTo().getId();
!                     if ((baseURL != null) && (toId.startsWith(baseURL)) && (toId.lastIndexOf('#') > -1)) {
!                         toId = toId.substring(toId.lastIndexOf('#'));
!                     }
!                     writer.writeStatement(id, edge.getType(), toId, null, null, false);
!                 }
!             }
!         }
! 
!         writer.finishRDFContents();
!         writer.cleanUp();
! 
!     }
! 
!     public void writeToRDF(OutputStream out, String baseURL) throws IOException {
! 
!         writeToRDF(this, out, baseURL);
!     }
! 
!     public synchronized Iterator<URL> readFromFile(File file) throws IOException {
  
          try {
+             URL url = new URL("file:///" + file.getAbsolutePath());
+             return readFromURL(url);
+         }
+         catch (MalformedURLException e) {
+             throw new IOException("Cannot construct URL from filename");
+         }
+ 
+     }
+ 
+     public synchronized Iterator<URL> readFromURL(URL url) throws IOException{
+ 
+         try {
+             loadingURLs = new ArrayList<URL>();
+             importFromURL(url);
+     
+             Iterator<URL> retVal = loadingURLs.iterator();
+     
+             return retVal;
+         }
+         finally {
+             loadingURLs = null;
+         }
+ 
+     }
+ 
+     /**
+      *  This is the internal method to load content from an URL. While readFromURL returns
+      *  the URLs loaded to the caller, this one adds the loaded URL to the list of URLs
+      *  to be returned.
+      * 
+      *  @param url The URL to load.
+      */
+     protected void importFromURL(URL url) throws IOException{
+ 
+         try {
+             loadingURL = url;
+             sourceNode = getNodeOrNew(loadingURL.toString());
+     
+             if (sourceNode.getNeighbours(NS.graphl + "definedIn", true).size() == 0) {
+                 Edge edge = createEdge(sourceNode, sourceNode);
+                 edge.setSource(NS.graphl + "SYSTEM");
+                 edge.setType(NS.graphl + "definedIn");
+             }
+     
+             InputSource input;
+     
              input = new InputSource(url.openConnection().getInputStream());
              input.setSystemId(url.toString());
              readGraph(input);
+             loadingURLs.add(url);
          }
!         finally {
!             loadingURL = null;
!             sourceNode = null;
!         }
!     }
! 
!     public synchronized void readGraph(InputSource input) {
! 
!         RDFParser parser = new RDFParser();
!         loading = true;
!         try {
!             parser.parse(input, this);
!         }
!         catch (Exception e) {
              e.printStackTrace();
          }
+         loading = false;
+         resetDirty();
+         fireGraphContentsChanged();
+     }
  
!     /**
!      * @see edu.unika.aifb.rdf.api.syntax.RDFConsumer#startModel(java.lang.String)
!      */
!     public void startModel(String physicalURI) throws SAXException {
! 
!         if (DEBUG) System.out.println("RDF: startModel");
!     }
! 
!     /**
!      * @see edu.unika.aifb.rdf.api.syntax.RDFConsumer#endModel()
!      */
!     public void endModel() throws SAXException {
! 
!         if (DEBUG) System.out.println("RDF: endModel");
!     }
! 
!     /**
!      * @see edu.unika.aifb.rdf.api.syntax.RDFConsumer#statementWithResourceValue(java.lang.String, java.lang.String, java.lang.String)
!      */
!     public void statementWithResourceValue(String subject, String predicate, String object) throws SAXException {
! 
!         //if (predicate.equals(NS.graphl + "connectedTo")) {
!         // get / create node with label subject
! 
!         if (loadingURL != null) {
!             try {
!                 subject = new URL(loadingURL, subject).toString();
!             }
!             catch (MalformedURLException muex) {
!                 // do nothing
!             }
!             try {
!                 object = new URL(loadingURL, object).toString();
!             }
!             catch (MalformedURLException muex) {
!                 // do nothing
!             }
!         }
! 
!         Node snode;
!         Node onode;
          try {
!             snode = getNodeOrNew(subject);
!             onode = getNodeOrNew(object);
! 
!             // get / create connection
!             List edges = snode.getEdgesFrom();
!             RDFEdge edge = null;
!             boolean exists = false;
! 
!             for (Iterator iter = edges.iterator(); iter.hasNext();) {
!                 edge = (RDFEdge) iter.next();
!                 if ((edge.getTo() == onode) && (edge.getType().equals(predicate))) {
!                     exists = true;
!                     break;
!                 }
!             }
! 
!             if (!exists) {
!                 edge = new RDFEdge(snode, onode);
!                 edge.setType(predicate);
!                 edge.setSource(loadingURL.toString());
!                 addElements(null, Collections.singleton(edge));
!                 if (DEBUG) System.out.println("created edge " + subject + ", " + predicate + ", " + object);
! 
!                 if (predicate.equals("http://www.w3.org/2002/07/owl#imports") || predicate.equals(NS.rdfs + "seeAlso")) {
!                 //if (predicate.equals("http://www.w3.org/2002/07/owl#imports")) {
!                     URL oldBase = loadingURL;
!                     Node oldSource = sourceNode;
!                     try {
!                         URL importURL = new URL(loadingURL, object);
!                         System.out.println("importing " + importURL.toString() + " ... ");
!                         importFromURL(importURL);
!                         // restore original base url
!                     }
!                     catch (Exception ex) {
!                         System.out.println("Error importing " + object);
!                     }
!                     finally {
!                         loadingURL = oldBase;
!                         sourceNode = oldSource;
!                     }
!                 }
!             }
!         }
!         catch (Exception ex) {
!             if (DEBUG) System.out.println("Error while reading triple: " + subject + ", " + predicate + ", " + object);
!             //ex.printStackTrace();
          }
  
+     }
  
!     public Node getNodeOrNew(String uri) {
  
+         RDFNode node = getNodeById(uri);
+         if (node == null) {
+             node = new RDFNode(this, uri);
+             float r = 20 + loadCount;
+             loadAlpha += 30 / r;
+             node.setCenter(r * Math.sin(loadAlpha), r * Math.cos(loadAlpha));
+             loadCount++;
+             addElements(Collections.singleton(node), null);
+             if (DEBUG) System.out.println("created node " + uri);
+         }
+         if (sourceNode != null) {
+             boolean found = false;
+             for (Iterator i = node.getNeighbours(NS.graphl + "definedIn", true).iterator(); i.hasNext();) {
+                 Node source = (Node) i.next();
+                 if (source.equals(sourceNode)) {
+                     found = true;
+                     break;
+                 }
+             }
+             if (!found) {
+                 Edge edge = createEdge(node, sourceNode);
+                 edge.setSource(NS.graphl + "SYSTEM");
+                 edge.setType(NS.graphl + "definedIn");
+             }
+         }
+         return node;
+     }
  
!     public Node createNode() {
  
+         RDFNode node = new RDFNode(this);
+         addElements(Collections.singleton(node), null);
+         return node;
+     }
  
!     public Edge createEdge(Node from, Node to) {
  
!         RDFEdge edge = new RDFEdge(from, to);
!         if (loadingURL != null) {
!             edge.setSource(loadingURL.toString());
!         }
!         else {
!             edge.setSource(NS.graphl + "USER");
!         }
!         addElements(null, Collections.singleton(edge));
!         return edge;
!     }
  
!     /**
!      * @see edu.unika.aifb.rdf.api.syntax.RDFConsumer#statementWithLiteralValue(java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.String)
!      */
!     public void statementWithLiteralValue(String subject, String predicate, String object, String language, String datatype) throws SAXException {
  
!         // get absolute URL for subject
!         if (loadingURL != null) {
!             try {
!                 subject = new URL(loadingURL, subject).toString();
!             }
!             catch (MalformedURLException muex) {
!                 // do nothing
!             }
!         }
  
!         Node snode;
!         try {
!             snode = getNodeOrNew(subject);
!             snode.setProperty(predicate, object);
!             if (DEBUG) System.out.println("created property " + subject + ", " + predicate + ", " + object);
!         }
!         catch (Exception ex) {
!             if (DEBUG) System.out.println("Error while reading triple: " + subject + ", " + predicate + ", " + object);
!         }
!     }
  
!     /**
!      * @see edu.unika.aifb.rdf.api.syntax.RDFConsumer#logicalURI(java.lang.String)
!      */
!     public void logicalURI(String logicalURI) throws SAXException {
  
+         if (DEBUG) System.out.println("RDF: logicalURI: " + logicalURI);
+     }
  
!     /**
!      * @see edu.unika.aifb.rdf.api.syntax.RDFConsumer#includeModel(java.lang.String, java.lang.String)
!      */
!     public void includeModel(String logicalURI, String physicalURI) throws SAXException {
  
+         if (DEBUG) System.out.println("RDF: includeModel: " + logicalURI + ", " + physicalURI);
+     }
  
!     /**
!      * @see edu.unika.aifb.rdf.api.syntax.RDFConsumer#addModelAttribte(java.lang.String, java.lang.String)
!      */
!     public void addModelAttribte(String key, String value) throws SAXException {
  
+         if (DEBUG) System.out.println("RDF: addModelAttribte" + key + ", " + value);
+     }
  
      /**
       * @return Returns the dirty flag.
       */
      public boolean isDirty() {
+ 
          return dirty;
      }
! 
      /**
       * @param dirty New value for dirty flag.
       */
      public void setDirty(boolean dirty) {
+ 
          this.dirty = dirty;
      }
! 
      public void setDirty() {
+ 
          setDirty(true);
      }
! 
      public void resetDirty() {
+ 
          setDirty(false);
      }
! 
      /*
       * Overrides @see de.fzi.wim.guibase.graphview.graph.DefaultGraph#addElements(java.util.Collection, java.util.Collection)
       */
      public synchronized void addElements(Collection nodes, Collection edges) {
+ 
          setDirty();
          super.addElements(nodes, edges);
! 
          if (nodes != null) {
!             for (Iterator iter = nodes.iterator(); iter.hasNext();) {
!                 RDFNode node = (RDFNode) iter.next();
!                 allNodes.put(node.getId(), node);
              }
          }
      }
! 
      /*
       * Overrides @see de.fzi.wim.guibase.graphview.graph.DefaultGraph#clear()
       */
      public synchronized void clear() {
+ 
          setDirty();
          allNodes.clear();
***************
*** 423,431 ****
          loadCount = 0;
      }
!     
      /*
       * Overrides @see de.fzi.wim.guibase.graphview.graph.DefaultGraph#deleteElements(java.util.Collection, java.util.Collection)
       */
      public synchronized void deleteElements(Collection nodes, Collection edges) {
          setDirty();
          super.deleteElements(nodes, edges);
--- 452,461 ----
          loadCount = 0;
      }
! 
      /*
       * Overrides @see de.fzi.wim.guibase.graphview.graph.DefaultGraph#deleteElements(java.util.Collection, java.util.Collection)
       */
      public synchronized void deleteElements(Collection nodes, Collection edges) {
+ 
          setDirty();
          super.deleteElements(nodes, edges);
***************
*** 433,441 ****
          if (nodes != null) {
              for (Iterator iter = nodes.iterator(); iter.hasNext();) {
! 	            RDFNode node = (RDFNode) iter.next();
! 	            allNodes.remove(node.getId());
              }
          }
      }
!     
  }
--- 463,471 ----
          if (nodes != null) {
              for (Iterator iter = nodes.iterator(); iter.hasNext();) {
!                 RDFNode node = (RDFNode) iter.next();
!                 allNodes.remove(node.getId());
              }
          }
      }
! 
  }