Code cleaning Ref #69

CityDoctorParent/CityDoctorModel/src/main/java/de/hft/stuttgart/citydoctor2/check/error/UnknownCheckError.java

@@ -30,6 +30,8 @@ import de.hft.stuttgart.citydoctor2.check.HealingMethod;
 import de.hft.stuttgart.citydoctor2.check.ModificationListener;
 import de.hft.stuttgart.citydoctor2.datastructure.GmlElement;
 
+import java.io.Serial;
+
 /**
  * This error is created when an unexpected exception is thrown by the code.
  * 
@@ -38,11 +40,12 @@ import de.hft.stuttgart.citydoctor2.datastructure.GmlElement;
  */
 public class UnknownCheckError implements CheckError {
 
+	@Serial
 	private static final long serialVersionUID = -6554097632341055596L;
 	
-	private Checkable c;
-	private Exception e;
-	private CheckId checkId;
+	private final Checkable c;
+	private final Exception e;
+	private final CheckId checkId;
 
 	public UnknownCheckError(Checkable c, Exception e, Check check) {
 		this.c = c;

CityDoctorParent/CityDoctorModel/src/main/java/de/hft/stuttgart/citydoctor2/datastructure/AbstractBuilding.java

@@ -18,6 +18,7 @@
  */
 package de.hft.stuttgart.citydoctor2.datastructure;
 
+import java.io.Serial;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -47,12 +48,13 @@ import de.hft.stuttgart.citydoctor2.utils.Copyable;
  */
 public abstract class AbstractBuilding extends CityObject {
 
+	@Serial
 	private static final long serialVersionUID = -2196414503088741206L;
 
 	private static final Logger logger = LogManager.getLogger(AbstractBuilding.class);
 
-	private List<Installation> buildingInstallations = new ArrayList<>(2);
-	private List<BoundarySurface> boundarySurfaceList = new ArrayList<>();
+	private final List<Installation> buildingInstallations = new ArrayList<>(2);
+	private final List<BoundarySurface> boundarySurfaceList = new ArrayList<>();
 
 	private org.citygml4j.core.model.building.AbstractBuilding ab;
 

CityDoctorParent/CityDoctorModel/src/main/java/de/hft/stuttgart/citydoctor2/datastructure/BoundarySurface.java

@@ -18,6 +18,7 @@
  */
 package de.hft.stuttgart.citydoctor2.datastructure;
 
+import java.io.Serial;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -42,12 +43,13 @@ import de.hft.stuttgart.citydoctor2.utils.Copyable;
  */
 public class BoundarySurface extends CityObject {
 
+	@Serial
 	private static final long serialVersionUID = 8793865135393496408L;
 
 	private SurfaceFeatureType featureType;
 	private BoundarySurfaceType type;
 
-	private List<Opening> openings = new ArrayList<>(2);
+	private final List<Opening> openings = new ArrayList<>(2);
 	private CityObject parent;
 
 	private AbstractThematicSurface gmlObject;

CityDoctorParent/CityDoctorModel/src/main/java/de/hft/stuttgart/citydoctor2/datastructure/BoundingBox.java

@@ -32,7 +32,7 @@ import de.hft.stuttgart.citydoctor2.utils.BoundingBoxCalculator;
  */
 public class BoundingBox {
 
-	private Vector3d[] bbox;
+	private final Vector3d[] bbox;
 
 	/**
 	 * Creates an axis aligned bounding box containing all points of all polygons
@@ -142,11 +142,7 @@ public class BoundingBox {
 	public double getLongestSide() {
 		double width = getWidth();
 		double depth = getDepth();
-		if (width > depth) {
-			return width;
-		} else {
-			return depth;
-		}
+        return Math.max(width, depth);
 	}
 
 	/**

CityDoctorParent/CityDoctorModel/src/main/java/de/hft/stuttgart/citydoctor2/datastructure/BridgeConstructiveElement.java

@@ -18,6 +18,7 @@
  */
 package de.hft.stuttgart.citydoctor2.datastructure;
 
+import java.io.Serial;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -47,10 +48,11 @@ public class BridgeConstructiveElement extends CityObject {
 
 	private static final String CANNOT_ADD = "Cannot add ";
 
+	@Serial
 	private static final long serialVersionUID = 7353233899458901155L;
 
-	private org.citygml4j.core.model.bridge.BridgeConstructiveElement gmlBridgeElement;
-	private List<BoundarySurface> boundarySurfaceList = new ArrayList<>();
+	private final org.citygml4j.core.model.bridge.BridgeConstructiveElement gmlBridgeElement;
+	private final List<BoundarySurface> boundarySurfaceList = new ArrayList<>();
 
 
 	public BridgeConstructiveElement(org.citygml4j.core.model.bridge.BridgeConstructiveElement gmlObject) {

CityDoctorParent/CityDoctorModel/src/main/java/de/hft/stuttgart/citydoctor2/datastructure/BridgeObject.java

@@ -18,9 +18,13 @@
  */
 package de.hft.stuttgart.citydoctor2.datastructure;
 
-import java.util.ArrayList;
-import java.util.List;
-
+import de.hft.stuttgart.citydoctor2.check.Check;
+import de.hft.stuttgart.citydoctor2.check.CheckError;
+import de.hft.stuttgart.citydoctor2.check.CheckId;
+import de.hft.stuttgart.citydoctor2.parser.ParserConfiguration;
+import de.hft.stuttgart.citydoctor2.utils.CityGmlUtils;
+import de.hft.stuttgart.citydoctor2.utils.CopyHandler;
+import de.hft.stuttgart.citydoctor2.utils.Copyable;
 import org.citygml4j.core.model.bridge.AbstractBridge;
 import org.citygml4j.core.model.bridge.BridgeInstallation;
 import org.citygml4j.core.model.bridge.BridgeInstallationProperty;
@@ -31,37 +35,25 @@ import org.xmlobjects.gml.model.geometry.aggregates.MultiSurfaceProperty;
 import org.xmlobjects.gml.model.geometry.primitives.Solid;
 import org.xmlobjects.gml.model.geometry.primitives.SolidProperty;
 
-import de.hft.stuttgart.citydoctor2.check.Check;
-import de.hft.stuttgart.citydoctor2.check.CheckError;
-import de.hft.stuttgart.citydoctor2.check.CheckId;
-import de.hft.stuttgart.citydoctor2.parser.ParserConfiguration;
-import de.hft.stuttgart.citydoctor2.utils.CityGmlUtils;
-import de.hft.stuttgart.citydoctor2.utils.CopyHandler;
-import de.hft.stuttgart.citydoctor2.utils.Copyable;
+import java.io.Serial;
+import java.util.ArrayList;
+import java.util.List;
 
 /**
  * Bridge representation object of CityGML bridge objects
  *
  * @author Matthias Betz
- *
  */
 public class BridgeObject extends CityObject {
 
+    @Serial
     private static final long serialVersionUID = 6301112640328373842L;
-
-	public enum BridgeType {
-		BRIDGE, BRIDGE_PART
-	}
-
+    private final List<BridgeObject> parts = new ArrayList<>(2);
+    private final List<BridgeConstructiveElement> elements = new ArrayList<>(2);
+    private final List<BoundarySurface> boundarySurfaces = new ArrayList<>(2);
+    private final List<Installation> bridgeInstallations = new ArrayList<>(2);
     private AbstractBridge ab;
     private BridgeType type;
-	
-	private List<BridgeObject> parts = null;
-	
-	private List<BridgeConstructiveElement> elements = null;
-	private List<BoundarySurface> boundarySurfaces = new ArrayList<>(2);
-	private List<Installation> bridgeInstallations = new ArrayList<>(2);
-	
     public BridgeObject(BridgeType type, AbstractBridge ab) {
         this.ab = ab;
         this.type = type;
@@ -73,9 +65,6 @@ public class BridgeObject extends CityObject {
     }
 
     public List<BridgeConstructiveElement> getConstructiveElements() {
-		if (elements == null) {
-			elements = new ArrayList<>(2);
-		}
         return elements;
     }
 
@@ -100,16 +89,13 @@ public class BridgeObject extends CityObject {
         for (Installation bi : bridgeInstallations) {
             bi.reCreateGeometries(factory, config);
         }
-		if (parts != null) {
         for (BridgeObject part : parts) {
             part.reCreateGeometries(factory, config);
         }
-		}
-		if (elements != null) {
         for (BridgeConstructiveElement ele : elements) {
             ele.reCreateGeometries(factory, config);
         }
-		}
+
     }
 
     private void setMultiSurfaceAccordingToLod(Geometry geom, MultiSurface ms) {
@@ -149,7 +135,6 @@ public class BridgeObject extends CityObject {
                 throw new IllegalStateException("Cannot add " + geom.getLod() + " solid to bridges");
         }
     }
-	
     public void addBridgeInstallation(Installation coBi) {
         bridgeInstallations.add(coBi);
         coBi.setParent(this);
@@ -164,17 +149,13 @@ public class BridgeObject extends CityObject {
         for (Installation bi : bridgeInstallations) {
             bi.clearAllContainedCheckResults();
         }
-		if (parts != null) {
         for (BridgeObject part : parts) {
             part.clearAllContainedCheckResults();
         }
-		}
-		if (elements != null) {
         for (BridgeConstructiveElement ele : elements) {
             ele.clearAllContainedCheckResults();
         }
     }
-	}
 
     @Override
     public void collectContainedErrors(List<CheckError> errors) {
@@ -185,16 +166,13 @@ public class BridgeObject extends CityObject {
         for (Installation bi : bridgeInstallations) {
             bi.collectContainedErrors(errors);
         }
-		if (parts != null) {
         for (BridgeObject part : parts) {
             part.collectContainedErrors(errors);
         }
-		}
-		if (elements != null) {
         for (BridgeConstructiveElement ele : elements) {
             ele.collectContainedErrors(errors);
         }
-		}
+
     }
 
     @Override
@@ -216,24 +194,21 @@ public class BridgeObject extends CityObject {
         if (doPartsContainAnyError()) {
             return true;
         }
-		if (elements != null) {
         for (BridgeConstructiveElement ele : elements) {
             if (ele.containsAnyError()) {
                 return true;
             }
         }
-		}
         return false;
     }
 
     private boolean doPartsContainAnyError() {
-		if (parts != null) {
+
         for (BridgeObject part : parts) {
             if (part.containsAnyError()) {
                 return true;
             }
         }
-		}
         return false;
     }
 
@@ -256,24 +231,21 @@ public class BridgeObject extends CityObject {
         if (doPartsContainError(checkIdentifier)) {
             return true;
         }
-		if (elements != null) {
         for (BridgeConstructiveElement ele : elements) {
             if (ele.containsError(checkIdentifier)) {
                 return true;
             }
         }
-		}
         return false;
     }
 
     private boolean doPartsContainError(CheckId checkIdentifier) {
-		if (parts != null) {
+
         for (BridgeObject part : parts) {
             if (part.containsError(checkIdentifier)) {
                 return true;
             }
         }
-		}
         return false;
     }
 
@@ -289,16 +261,13 @@ public class BridgeObject extends CityObject {
         for (Installation bi : bridgeInstallations) {
             bi.accept(c);
         }
-		if (parts != null) {
         for (BridgeObject part : parts) {
             part.accept(c);
         }
-		}
-		if (elements != null) {
         for (BridgeConstructiveElement ele : elements) {
             ele.accept(c);
         }
-		}
+
     }
 
     /**
@@ -329,6 +298,10 @@ public class BridgeObject extends CityObject {
         return ab;
     }
 
+    public void setGmlObject(AbstractBridge aBridge) {
+        ab = aBridge;
+    }
+
     @Override
     public void unsetGmlGeometries() {
         ab.setLod1Solid(null);
@@ -345,20 +318,13 @@ public class BridgeObject extends CityObject {
         for (Installation bi : bridgeInstallations) {
             bi.unsetGmlGeometries();
         }
-		if (parts != null) {
         for (BridgeObject part : parts) {
             part.unsetGmlGeometries();
         }
-		}
-		if (elements != null) {
         for (BridgeConstructiveElement ele : elements) {
             ele.unsetGmlGeometries();
         }
-		}
-	}
 
-	public void setGmlObject(AbstractBridge aBridge) {
-		ab = aBridge;
     }
 
     @Override
@@ -369,16 +335,13 @@ public class BridgeObject extends CityObject {
     @Override
     public void prepareForChecking() {
         super.prepareForChecking();
-		if (elements != null) {
+
         for (BridgeConstructiveElement e : elements) {
             e.prepareForChecking();
         }
-		}
-		if (parts != null) {
         for (BridgeObject part : parts) {
             part.prepareForChecking();
         }
-		}
         for (BoundarySurface bs : boundarySurfaces) {
             bs.prepareForChecking();
         }
@@ -396,16 +359,16 @@ public class BridgeObject extends CityObject {
         for (Installation bi : bridgeInstallations) {
             bi.clearMetaInformation();
         }
-		if (parts != null) {
+
         for (BridgeObject part : parts) {
             part.clearMetaInformation();
         }
-		}
-		if (elements != null) {
+
+
         for (BridgeConstructiveElement ele : elements) {
             ele.clearMetaInformation();
         }
-		}
+
     }
 
     @Override
@@ -417,16 +380,16 @@ public class BridgeObject extends CityObject {
         for (Installation bi : bridgeInstallations) {
             handler.addInstance(bi);
         }
-		if (parts != null) {
+
         for (BridgeObject part : parts) {
             handler.addInstance(part);
         }
-		}
-		if (elements != null) {
+
+
         for (BridgeConstructiveElement ele : elements) {
             handler.addInstance(ele);
         }
-		}
+
     }
 
     public void anonymize() {
@@ -446,7 +409,6 @@ public class BridgeObject extends CityObject {
         this.ab = gmlB;
     }
 
-	
     @Override
     public void fillValues(Copyable original, CopyHandler handler) {
         super.fillValues(original, handler);
@@ -457,16 +419,16 @@ public class BridgeObject extends CityObject {
         for (Installation originalBi : originalBo.bridgeInstallations) {
             bridgeInstallations.add(handler.getCopyInstance(originalBi));
         }
-		if (originalBo.parts != null) {
+
         for (BridgeObject part : originalBo.parts) {
             getParts().add(handler.getCopyInstance(part));
         }
-		}
-		if (originalBo.elements != null) {
+
+
         for (BridgeConstructiveElement ele : originalBo.elements) {
             getConstructiveElements().add(handler.getCopyInstance(ele));
         }
-		}
+
     }
 
     public List<BoundarySurface> getBoundarySurfaces() {
@@ -483,9 +445,6 @@ public class BridgeObject extends CityObject {
     }
 
     public List<BridgeObject> getParts() {
-		if (parts == null) {
-			parts  = new ArrayList<>(2);
-		}
         return parts;
     }
 
@@ -493,4 +452,8 @@ public class BridgeObject extends CityObject {
         getParts().add(bPart);
     }
 
+    public enum BridgeType {
+        BRIDGE, BRIDGE_PART
+    }
+
 }

CityDoctorParent/CityDoctorModel/src/main/java/de/hft/stuttgart/citydoctor2/datastructure/Building.java

@@ -18,6 +18,7 @@
  */
 package de.hft.stuttgart.citydoctor2.datastructure;
 
+import java.io.Serial;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -35,9 +36,10 @@ import de.hft.stuttgart.citydoctor2.utils.Copyable;
 
 public class Building extends AbstractBuilding {
 
+	@Serial
 	private static final long serialVersionUID = 588480113268630052L;
 
-	private List<BuildingPart> buildingParts = new ArrayList<>(2);
+	private final List<BuildingPart> buildingParts = new ArrayList<>(2);
 
 	public List<BuildingPart> getBuildingParts() {
 		return buildingParts;

CityDoctorParent/CityDoctorModel/src/main/java/de/hft/stuttgart/citydoctor2/datastructure/BuildingPart.java

@@ -21,8 +21,11 @@ package de.hft.stuttgart.citydoctor2.datastructure;
 import de.hft.stuttgart.citydoctor2.utils.CopyHandler;
 import de.hft.stuttgart.citydoctor2.utils.Copyable;
 
+import java.io.Serial;
+
 public class BuildingPart extends AbstractBuilding {
 	
+	@Serial
 	private static final long serialVersionUID = 8200322261958679163L;
 	
 	private Building parent;

CityDoctorParent/CityDoctorModel/src/main/java/de/hft/stuttgart/citydoctor2/datastructure/CityDoctorModel.java

@@ -53,17 +53,17 @@ import de.hft.stuttgart.quality.model.types.ValidationPlan;
 public class CityDoctorModel {
 
 	private static final String COULD_NOT_FIND_FEATURE = "Could not find feature: ";
-	private List<Building> buildings;
-	private List<Vegetation> vegetation;
-	private List<BridgeObject> bridges;
-	private List<CityObject> land;
-	private List<TransportationObject> roads;
-	private List<WaterObject> water;
+	private final List<Building> buildings;
+	private final List<Vegetation> vegetation;
+	private final List<BridgeObject> bridges;
+	private final List<CityObject> land;
+	private final List<TransportationObject> roads;
+	private final List<WaterObject> water;
 	private CityModel cModel;
-	private ParserConfiguration config;
-	private String fileName;
-	private File file;
-	private List<CheckError> globalErrors;
+	private final ParserConfiguration config;
+	private final String fileName;
+	private final File file;
+	private final List<CheckError> globalErrors;
 	private boolean isValidated = false;
 	private ValidationPlan plan;
 	private CityGMLVersion cityGMLVersion;

CityDoctorParent/CityDoctorModel/src/main/java/de/hft/stuttgart/citydoctor2/datastructure/CityObject.java

@@ -18,6 +18,7 @@
  */
 package de.hft.stuttgart.citydoctor2.datastructure;
 
+import java.io.Serial;
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
@@ -43,9 +44,10 @@ import de.hft.stuttgart.citydoctor2.utils.Copyable;
  */
 public abstract class CityObject extends GmlElement {
 
+	@Serial
 	private static final long serialVersionUID = 651712070755024188L;
 
-	private List<Geometry> geometryList = new ArrayList<>();
+	private final List<Geometry> geometryList = new ArrayList<>();
 
 	/**
 	 * Recreates the CityGML4j geometry in this object. The CityGML4j geometry is
@@ -83,23 +85,11 @@ public abstract class CityObject extends GmlElement {
 	}
 
 	public void removeGeometry(Lod lod) {
-		Iterator<Geometry> it = geometryList.iterator();
-		while (it.hasNext()) {
-			Geometry next = it.next();
-			if (next.getLod() == lod) {
-				it.remove();
-			}
-		}
+        geometryList.removeIf(geom -> geom.getLod() == lod);
 	}
 	
 	public void removeGeometry(Lod lod, GeometryType type) {
-		Iterator<Geometry> it = geometryList.iterator();
-		while (it.hasNext()) {
-			Geometry next = it.next();
-			if (next.getLod() == lod && next.getType() == type) {
-				it.remove();
-			}
-		}
+        geometryList.removeIf(geom -> geom.getLod() == lod && geom.getType() == type);
 	}
 
 	public Geometry getHighestLodGeometry() {

CityDoctorParent/CityDoctorModel/src/main/java/de/hft/stuttgart/citydoctor2/datastructure/ConcretePolygon.java

@@ -18,6 +18,7 @@
  */
 package de.hft.stuttgart.citydoctor2.datastructure;
 
+import java.io.Serial;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
@@ -41,6 +42,7 @@ import de.hft.stuttgart.citydoctor2.utils.Copyable;
  */
 public class ConcretePolygon extends Polygon {
 
+	@Serial
 	private static final long serialVersionUID = -2208347892270418372L;
 
 	private LinearRing exterior;

CityDoctorParent/CityDoctorModel/src/main/java/de/hft/stuttgart/citydoctor2/datastructure/Edge.java

@@ -18,6 +18,7 @@
  */
 package de.hft.stuttgart.citydoctor2.datastructure;
 
+import java.io.Serial;
 import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.List;
@@ -33,10 +34,11 @@ import de.hft.stuttgart.citydoctor2.utils.Copyable;
  */
 public class Edge implements Serializable, Copyable {
 
+	@Serial
 	private static final long serialVersionUID = -504694863498128296L;
 
-	private List<Polygon> adjacentPolygons = new ArrayList<>(2);
-	private List<LinearRing> adjacentRings = new ArrayList<>(2);
+	private final List<Polygon> adjacentPolygons = new ArrayList<>(2);
+	private final List<LinearRing> adjacentRings = new ArrayList<>(2);
 
 	private Vertex from;
 	private Vertex to;
@@ -78,15 +80,7 @@ public class Edge implements Serializable, Copyable {
 	}
 
 	private boolean isPointOfEdge(Vertex v0, Vertex edgePoint) {
-		if (v0.equals(edgePoint)) {
-			return true;
-		}
-//		for (Vertex v : v0.getNeighbors()) {
-//			if (v.equals(edgePoint)) {
-//				return true;
-//			}
-//		}
-		return false;
+        return v0.equals(edgePoint);
     }
 
 	public boolean formedByIgnoreDirection(Vertex v1, Vertex v2) {
@@ -146,13 +140,8 @@ public class Edge implements Serializable, Copyable {
 			return false;
 		}
 		if (to == null) {
-			if (other.to != null) {
-				return false;
-			}
-		} else if (!to.equals(other.to)) {
-			return false;
-		}
-		return true;
+            return other.to == null;
+		} else return to.equals(other.to);
     }
 
 	public void addAdjacentPolygon(Polygon p) {

CityDoctorParent/CityDoctorModel/src/main/java/de/hft/stuttgart/citydoctor2/datastructure/FeatureType.java

@@ -27,6 +27,6 @@ package de.hft.stuttgart.citydoctor2.datastructure;
 public enum FeatureType {
 
 	BUILDING, TRANSPORTATION, VEGETATION, BRIDGE, LAND, WATER, BOUNDARY_SURFACE, INSTALLATION, OPENING,
-	BUILDING_PART, BRIDGE_CONSTRUCTION_ELEMENT, BRIDGE_INSTALLATION;
+	BUILDING_PART, BRIDGE_CONSTRUCTION_ELEMENT, BRIDGE_INSTALLATION
 
 }

CityDoctorParent/CityDoctorModel/src/main/java/de/hft/stuttgart/citydoctor2/datastructure/Geometry.java

@@ -18,6 +18,7 @@
  */
 package de.hft.stuttgart.citydoctor2.datastructure;
 
+import java.io.Serial;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.HashSet;
@@ -48,16 +49,17 @@ public class Geometry extends GmlElement {
 
 	private static final String FAILED_REMOVING_POLYGON = "Removing polygon %s but polygon is not in geometry";
 
+	@Serial
 	private static final long serialVersionUID = 2539031030917731575L;
 
-	private static Random r = new Random();
+	private static final Random r = new Random();
 
 	private GeometryType type;
-	private Lod lod;
+	private final Lod lod;
 
 	private CityObject parent;
 
-	private List<Polygon> polygons = new ArrayList<>(2);
+	private final List<Polygon> polygons = new ArrayList<>(2);
 	private List<Edge> edges;
 	private Map<SerializablePair<Vertex, Vertex>, Edge> edgeMap;
 	private List<Vertex> vertices;
@@ -153,7 +155,7 @@ public class Geometry extends GmlElement {
 		}
 		// only go to size -1 as ring should be closed
 		for (int i = 0; i < ring.getVertices().size() - 1; i++) {
-			Vertex v0 = ring.getVertices().get(i + 0);
+			Vertex v0 = ring.getVertices().get(i);
 			Vertex v1 = ring.getVertices().get(i + 1);
 			Edge tempEdge = new Edge(v0, v1);
 			Edge e = duplicacyMap.get(tempEdge);

CityDoctorParent/CityDoctorModel/src/main/java/de/hft/stuttgart/citydoctor2/datastructure/GmlElement.java

@@ -22,6 +22,8 @@ import de.hft.stuttgart.citydoctor2.check.Checkable;
 import de.hft.stuttgart.citydoctor2.utils.CopyHandler;
 import de.hft.stuttgart.citydoctor2.utils.Copyable;
 
+import java.io.Serial;
+
 /**
  * A general GML element that has a gml id
  * 
@@ -30,6 +32,7 @@ import de.hft.stuttgart.citydoctor2.utils.Copyable;
  */
 public abstract class GmlElement extends Checkable implements Copyable {
 
+	@Serial
 	private static final long serialVersionUID = -3242505393303017359L;
 
 	private GmlId gmlId;

CityDoctorParent/CityDoctorModel/src/main/java/de/hft/stuttgart/citydoctor2/datastructure/GmlId.java

@@ -18,6 +18,7 @@
  */
 package de.hft.stuttgart.citydoctor2.datastructure;
 
+import java.io.Serial;
 import java.io.Serializable;
 import java.util.concurrent.atomic.AtomicInteger;
 
@@ -30,14 +31,15 @@ import java.util.concurrent.atomic.AtomicInteger;
  */
 public class GmlId implements Serializable {
 
+	@Serial
 	private static final long serialVersionUID = 4273817255150972966L;
 
 	/* prefixes for generation */
 	private static final String GENERAL_GEN = "CityDoctor_%d_%d";
 	private static final AtomicInteger ID_COUNTER = new AtomicInteger();
 
-	private String gmlString;
-	private boolean generated;
+	private final String gmlString;
+	private final boolean generated;
 
 	public GmlId(String gmlId) {
 		this(gmlId, false);
@@ -85,13 +87,8 @@ public class GmlId implements Serializable {
 			return false;
 		}
 		if (gmlString == null) {
-			if (other.gmlString != null) {
-				return false;
-			}
-		} else if (!gmlString.equals(other.gmlString)) {
-			return false;
-		}
-		return true;
+            return other.gmlString == null;
+		} else return gmlString.equals(other.gmlString);
     }
 
 	/**

CityDoctorParent/CityDoctorModel/src/main/java/de/hft/stuttgart/citydoctor2/datastructure/Installation.java

@@ -18,6 +18,7 @@
  */
 package de.hft.stuttgart.citydoctor2.datastructure;
 
+import java.io.Serial;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -41,6 +42,7 @@ import de.hft.stuttgart.citydoctor2.utils.Copyable;
 
 public class Installation extends CityObject {
 
+	@Serial
 	private static final long serialVersionUID = 1576237433322680191L;
 
 	private List<BoundarySurface> boundarySurfaces = new ArrayList<>(4);

CityDoctorParent/CityDoctorModel/src/main/java/de/hft/stuttgart/citydoctor2/datastructure/LandObject.java

@@ -29,6 +29,8 @@ import de.hft.stuttgart.citydoctor2.parser.ParserConfiguration;
 import de.hft.stuttgart.citydoctor2.utils.CityGmlUtils;
 import de.hft.stuttgart.citydoctor2.utils.Copyable;
 
+import java.io.Serial;
+
 /**
  * Represents a land use CityGML object.
  * 
@@ -37,6 +39,7 @@ import de.hft.stuttgart.citydoctor2.utils.Copyable;
  */
 public class LandObject extends CityObject {
 
+	@Serial
 	private static final long serialVersionUID = 1887455662411087326L;
 
 	private LandUse lu;

CityDoctorParent/CityDoctorModel/src/main/java/de/hft/stuttgart/citydoctor2/datastructure/LinearRing.java

@@ -18,6 +18,7 @@
  */
 package de.hft.stuttgart.citydoctor2.datastructure;
 
+import java.io.Serial;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -38,12 +39,13 @@ import de.hft.stuttgart.citydoctor2.utils.Copyable;
  */
 public class LinearRing extends GmlElement {
 
+	@Serial
 	private static final long serialVersionUID = -2488180830514940722L;
 
 	private LinearRingType type;
 	private Polygon parent;
 
-	private List<Vertex> vertices = new ArrayList<>();
+	private final List<Vertex> vertices = new ArrayList<>();
 
 	public enum LinearRingType {
 		EXTERIOR, INTERIOR
@@ -130,7 +132,7 @@ public class LinearRing extends GmlElement {
 	public Vector3d calculateNormal() {
 		double[] coords = new double[3];
 		for (int i = 0; i < vertices.size() - 1; i++) {
-			Vertex current = vertices.get(i + 0);
+			Vertex current = vertices.get(i);
 			Vertex next = vertices.get(i + 1);
 			coords[0] += (current.getZ() + next.getZ()) * (current.getY() - next.getY());
 			coords[1] += (current.getX() + next.getX()) * (current.getZ() - next.getZ());

CityDoctorParent/CityDoctorModel/src/main/java/de/hft/stuttgart/citydoctor2/datastructure/LinkedPolygon.java

@@ -18,6 +18,7 @@
  */
 package de.hft.stuttgart.citydoctor2.datastructure;
 
+import java.io.Serial;
 import java.util.List;
 import java.util.Map;
 
@@ -39,6 +40,7 @@ import de.hft.stuttgart.citydoctor2.utils.Copyable;
  */
 public class LinkedPolygon extends Polygon {
 
+	@Serial
 	private static final long serialVersionUID = -4897578390280277931L;
 
 	private Geometry parent;