Checkstyle

src/edu/kit/informatik/Main.java

@@ -8,7 +8,14 @@ import edu.kit.informatik.ui.CommandLine;
  * @author Arne Keller
  * @version 1.0
  */
-public class Main {
+public final class Main {
+    /**
+     * Utility class -> private constructor.
+     */
+    private Main() {
+        
+    }
+
     /**
      * Program entry point.
      * @param args command-line arguments

src/edu/kit/informatik/model/ModelRailwaySimulation.java

@@ -402,8 +402,8 @@ public class ModelRailwaySimulation {
      * Get collisions of trains currently placed.
      * @return list of collisions (never null, sometimes empty)
      */
-    private ArrayList<HashSet<Train>> getStaticCollisions() {
+    private List<HashSet<Train>> getStaticCollisions() {
-        ArrayList<HashSet<Train>> collisions = new ArrayList<>();
+        List<HashSet<Train>> collisions = new ArrayList<>();
         int maxId = trains.keySet().stream().max(Integer::compareTo).orElse(0);
         train: for (int id1 = 1; id1 <= maxId; id1++) {
             Train train1 = trains.get(id1);
@@ -421,7 +421,7 @@ public class ModelRailwaySimulation {
                     collision.add(train2);
                 }
             }
-            if (collision.size() >= 1) {
+            if (!collision.isEmpty()) {
                 // check for existing collision
                 for (HashSet<Train> otherCollision : collisions) {
                     if (otherCollision.stream().anyMatch(collision::contains)) {
@@ -441,8 +441,8 @@ public class ModelRailwaySimulation {
      * Get collisions of moving the trains one step forward.
      * @return list of collisions (never null, sometimes empty)
      */
-    private ArrayList<Set<Train>> getCollisionsOfOneStep() {
+    private List<Set<Train>> getCollisionsOfOneStep() {
-        ArrayList<Set<Train>> collisions = new ArrayList<>();
+        List<Set<Train>> collisions = new ArrayList<>();
         Map<Train, Set<Rail>> occupiedRails = new HashMap<>();
         for (Train train : trains.values()) {
             if (train.isPlaced()) {
@@ -456,8 +456,7 @@ public class ModelRailwaySimulation {
             Vector2D direction = train.getDirection();
             Vector2D nextPosition = railNetwork.move(position, direction);
             if (nextPosition == null
-                    || (train.isOnPosition(nextPosition)
+                    || train.isOnPosition(nextPosition) && !train.getRearPosition().equals(train.getFrontPosition())) {
-                    && !train.getRearPosition().equals(train.getFrontPosition()))) {
                 collisions.add(new HashSet<>(Arrays.asList(train)));
                 train.removeFromRails();
                 nextOccupiedRails.put(train, occupiedRails.get(train));
@@ -512,8 +511,8 @@ public class ModelRailwaySimulation {
      * Get collisions of moving the trains one step backward.
      * @return list of collisions (never null, sometimes empty)
      */
-    private ArrayList<Set<Train>> getCollisionsOfOneReverseStep() {
+    private List<Set<Train>> getCollisionsOfOneReverseStep() {
-        ArrayList<Set<Train>> collisions = new ArrayList<>();
+        List<Set<Train>> collisions = new ArrayList<>();
         Map<Train, Set<Rail>> occupiedRails = new HashMap<>();
         for (Train train : trains.values()) {
             if (train.isPlaced()) {
@@ -531,7 +530,7 @@ public class ModelRailwaySimulation {
             Vector2D direction = train.getRearDirection();
             Vector2D nextPosition = railNetwork.move(position, direction);
             if (nextPosition == null
-                    || (train.isOnPosition(nextPosition) && !train.getFrontPosition().equals(nextPosition))) {
+                    || train.isOnPosition(nextPosition) && !train.getFrontPosition().equals(nextPosition)) {
                 collisions.add(new HashSet<>(Arrays.asList(train)));
                 train.removeFromRails();
                 nextOccupiedRails.put(train, occupiedRails.get(train));

src/edu/kit/informatik/model/RailwayNetwork.java

@@ -103,7 +103,7 @@ public class RailwayNetwork {
      * @return whether the rail could be successfully removed
      */
     public boolean removeRail(final int id) {
-        if (rails.size() == 0) {
+        if (rails.isEmpty()) {
             return false;
         }
         Rail toRemove = rails.get(id);
@@ -223,8 +223,8 @@ public class RailwayNetwork {
             return nextPosition;
         }
         Vector2D previousPosition = position.add(direction.negated());
-        Rail nextRail = (touchingRails[0].contains(previousPosition)
+        Rail nextRail = touchingRails[0].contains(previousPosition)
-                || touchingRails[0].canConnectTo(previousPosition)) ? touchingRails[1] : touchingRails[0];
+                || touchingRails[0].canConnectTo(previousPosition) ? touchingRails[1] : touchingRails[0];
         Vector2D nextDirection = nextRail.getDirectionFrom(position);
         if (nextDirection != null) {
             direction.setX(nextDirection.getX());

src/edu/kit/informatik/model/Track.java

@@ -67,12 +67,12 @@ public final class Track extends Rail {
             int startY = start.getY();
             int endY = end.getY();
             int positionY = position.getY();
-            return (startY < positionY && positionY < endY) || (startY > positionY && positionY > endY);
+            return startY < positionY && positionY < endY || startY > positionY && positionY > endY;
         } else if (start.getY() == end.getY() && position.getY() == start.getY()) {
             int startX = start.getX();
             int endX = end.getX();
             int positionX = position.getX();
-            return (startX < positionX && positionX < endX) || (startX > positionX && positionX > endX);
+            return startX < positionX && positionX < endX || startX > positionX && positionX > endX;
         }
         return false;
     }

src/edu/kit/informatik/model/Train.java

@@ -25,7 +25,8 @@ public final class Train {
      */
     private final List<RollingStock> rollingStocks = new ArrayList<>();
     /**
-     * List of positions this train touches.
+     * List of positions this train touches. This is a linked list because we only have to update the first and last
+     * positions when moving the train.
      */
     private LinkedList<Vector2D> position;
     /**
@@ -161,7 +162,7 @@ public final class Train {
         for (int i = 1; i <= length; i++) {
             rollingStockPosition = railNetwork.move(rollingStockPosition, positioningDirection);
             if (rollingStockPosition == null
-                    || (positions.contains(rollingStockPosition) && !positions.get(0).equals(rollingStockPosition))) {
+                    || positions.contains(rollingStockPosition) && !positions.get(0).equals(rollingStockPosition)) {
                 return false;
             }
             positions.addLast(rollingStockPosition);
@@ -209,8 +210,7 @@ public final class Train {
         // the first or last rolling stock HAVE TO BE an engine OR a train-set!
         // therefore, no other rolling stock types should be allowed at all.
         // TODO: consider using first.canBeAtFront() ???
-        return (first instanceof Engine || first instanceof TrainSet)
+        return first instanceof Engine || first instanceof TrainSet || last instanceof Engine;
-                || last instanceof Engine;
     }
 
     /**
@@ -381,6 +381,6 @@ public final class Train {
      * @return total length of this train
      */
     public long getLength() {
-        return rollingStocks.stream().mapToLong((RollingStock::getLength)).sum();
+        return rollingStocks.stream().mapToLong(RollingStock::getLength).sum();
     }
 }

src/edu/kit/informatik/ui/CommandLine.java

@@ -11,12 +11,19 @@ import edu.kit.informatik.ui.command.CommandFactory;
  * @author Arne Keller
  * @version 1.0
  */
-public class CommandLine {
+public final class CommandLine {
     /**
      * Command used to exit the simulation and terminate the program.
      */
     private static final String EXIT = "exit";
 
+    /**
+     * Utility class -> private constructor.
+     */
+    private CommandLine() {
+        
+    }
+
     /**
      * Start a new interactive user session. Returns when standard in is fully processed or user exits.
      */

src/edu/kit/informatik/ui/command/CommandFactory.java

@@ -17,7 +17,7 @@ import java.util.regex.Pattern;
 public final class CommandFactory {
     private static final String NUMBER = "[+-]?\\d+";
     private static final String VECTOR = NUMBER + "," + NUMBER;
-    private static final String ALPHANUMERIC_WORD = "[\\p{L}\\p{N}]+";
+    private static final String ALPHANUMERIC_WORD = "[\\p{L}\\d]+";
     private static final String ROLLING_STOCK_IDENTIFIER
             = "(" + ALPHANUMERIC_WORD + "-" + ALPHANUMERIC_WORD + ")|W" + NUMBER;
 
@@ -58,6 +58,13 @@ public final class CommandFactory {
         = Pattern.compile(" (" + NUMBER + ") at \\((" + VECTOR + ")\\) in direction (" + VECTOR + ")");
     private static final String STEP = "step";
 
+    /**
+     * Utility class -> private constructor.
+     */
+    private CommandFactory() {
+        
+    }
+
     /**
      * Parse a single line of user input into one command.
      * @param command user input line
@@ -113,7 +120,7 @@ public final class CommandFactory {
             }
             EngineType type = EngineType.parse(matcher.group(1));
             String series = matcher.group(2);
-            if (series.equals("W")) {
+            if ("W".equals(series)) {
                 throw new InvalidInputException("invalid engine class/series");
             }
             String name = matcher.group(3);
@@ -149,7 +156,7 @@ public final class CommandFactory {
                 throw new InvalidInputException("invalid create train-set arguments");
             }
             String series = matcher.group(1);
-            if (series.equals("W")) {
+            if ("W".equals(series)) {
                 throw new InvalidInputException("invalid train-set class/series");
             }
             String name = matcher.group(2);