Tests now pass with iterator.

src/eu/simstadt/lowlevelgmlparser/BuildingXmlNode.java

@@ -21,7 +21,7 @@
 
 	public BuildingXmlNode(VTDNav navigator, int buildingOffset, int buildingLength) {
 		this.navigator = navigator;
-		this.coordinatesFinder = new AutoPilot(navigator); //COULD BE STATIC?
+		this.coordinatesFinder = new AutoPilot(navigator);
 		this.buildingLength = buildingLength;
 		this.buildingOffset = buildingOffset;
 	}

src/eu/simstadt/lowlevelgmlparser/CityGmlIterator.java

 package eu.simstadt.lowlevelgmlparser;
 
 import java.io.IOException;
+import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.Iterator;
 import java.util.logging.Logger;
@@ -20,12 +21,21 @@ public class CityGmlIterator implements Iterable<BuildingXmlNode>
 	private AutoPilot buildingsFinder;
 	private VTDNav navigator;
 	private long offsetAndLength;
-	private int buildingsCount = 0;
 	private int buildingOffset = 0;
 	private int buildingLength = 0;
+	private Path citygmlPath;
 
+	/*
+	 * Simple class to parse a CityGML and extract cityObjectMember XML nodes and their coordinates. Since the
+	 * coordinates are extracted for RegionChooser, it's okay to not be perfectly robust, but it should be fast and not
+	 * use much memory.
+	 * 
+	 * Based on VTD XML, it provides a Building iterator.
+	 * 
+	 */
 	public CityGmlIterator(Path citygmlPath)
 			throws XPathParseException, NavException, NumberFormatException, XPathEvalException, IOException {
+		this.citygmlPath = citygmlPath;
 		VTDGen parser = new VTDGen();
 		parser.parseFile(citygmlPath.toString(), false);
 		this.navigator = parser.getNav();
@@ -41,22 +51,22 @@ public Iterator<BuildingXmlNode> iterator() {
 			public boolean hasNext() {
 				try {
 					return buildingsFinder.evalXPath() != -1;
-				} catch (XPathEvalException | NavException ex) {}
-				return false;
+				} catch (XPathEvalException | NavException ex) {
+					LOGGER.warning("Error while parsing " + citygmlPath);
+					return false;
+				}
 			}
 
 			@Override
 			public BuildingXmlNode next() {
 				try {
-					buildingsCount += 1;
-					if (buildingsCount % 1000 == 0) {
-						LOGGER.info("1000 buildings parsed");
-					}
 					offsetAndLength = navigator.getElementFragment();
 					buildingOffset = (int) offsetAndLength;
 					buildingLength = (int) (offsetAndLength >> 32);
 					return new BuildingXmlNode(navigator, buildingOffset, buildingLength);
-				} catch (NavException ex) {}
+				} catch (NavException ex) {
+					LOGGER.warning("Error while parsing " + citygmlPath);
+				}
 				return null;
 			}
 
@@ -68,4 +78,14 @@ public void remove() {
 		return it;
 	}
 
+	public String getHeader() throws NavException {
+		return navigator.toRawString(0, buildingOffset);
+	}
+
+	public Object getFooter() throws IOException, NavException {
+		int footerOffset = buildingOffset + buildingLength;
+		int footerLength = (int) (Files.size(citygmlPath) - footerOffset);
+		return navigator.toRawString(footerOffset, footerLength);
+	}
+
 }

src/eu/simstadt/regionchooser/RegionExtractor.java

@@ -33,21 +33,22 @@ static public StringBuffer selectRegionDirectlyFromCityGML(Path citygmlPath, Str
 
 		CityGmlIterator citygml = new CityGmlIterator(citygmlPath);
 		for (BuildingXmlNode buildingXmlNode : citygml) {
-			buildingsCount += 1;
-			if (buildingsCount % 1000 == 0) {
-				LOGGER.info("1000 buildings parsed");
+			if (buildingsCount == 0) {
+				sb.append(citygml.getHeader());
 			}
+			buildingsCount += 1;
 			Point point = buildingXmlNode.getCenterOfMass();
 			if (point.within(poly)) {
 				foundBuildingsCount++;
 				sb.append(buildingXmlNode.toString());
 			}
+			if (buildingsCount % 1000 == 0) {
+				LOGGER.info("1000 buildings parsed");
+			}
 		}
 
 		LOGGER.info("Buildings found in selected region " + foundBuildingsCount);
-		//		int footerOffset = buildingOffset + buildingLength;
-		//		int footerLength = (int) (Files.size(citygmlPath) - footerOffset);
-		//		sb.append(navigator.toRawString(footerOffset, footerLength));
+		sb.append(citygml.getFooter());
 
 		return sb;
 	}