Checkstyle

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

@@ -21,10 +21,6 @@ public abstract class Coach extends RollingStock {
      * Pattern to match a single coach identifier.
      */
     public static final Pattern IDENTIFIER_PATTERN = Pattern.compile(IDENTIFIER_PREFIX + NUMBER);
-    /**
-     * Pattern to match coach type (passenger, freight, or special).
-     */
-    public static final String COACH_TYPE = "passenger|freight|special";
 
     /**
      * The (unique) identifier of this coach.

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

@@ -149,19 +149,7 @@ public class ModelRailwaySimulation {
         if (id < 0) {
             return -1;
         }
-        switch (coachType) {
+        coaches.put(id, coachType.createCoach(id, length, couplingFront, couplingBack));
-            case PASSENGER:
-                coaches.put(id, new PassengerCoach(id, length, couplingFront, couplingBack));
-                break;
-            case FREIGHT:
-                coaches.put(id, new FreightCoach(id, length, couplingFront, couplingBack));
-                break;
-            case SPECIAL:
-                coaches.put(id, new SpecialCoach(id, length, couplingFront, couplingBack));
-                break;
-            default:
-                throw new IllegalArgumentException("coach type is null");
-        }
         return id;
     }
 
@@ -223,7 +211,7 @@ public class ModelRailwaySimulation {
     }
 
     /**
-     * Delete a rolling stock.
+     * Delete a rolling stock. Will not return rolling stock used in a train, you have to delete the train first!
      *
      * @param id identifier of the rolling stock to remove
      * @return whether the rolling was successfully removed
@@ -231,11 +219,12 @@ public class ModelRailwaySimulation {
     public boolean deleteRollingStock(String id) {
         final Optional<RollingStock> rollingStock = getRollingStock(id);
         if (!rollingStock.isPresent()) {
-            return false;
+            return false; // can not remove imaginary rolling stock
         }
         if (trainManager.getTrainContainingRollingStock(rollingStock.get()).isPresent()) {
             return false; // can not delete rolling stock in use
         }
+        // remove the rolling stock from one of the collections
         return engines.remove(rollingStock.get())
                 || trainSets.remove(rollingStock.get())
                 || coaches.values().remove(rollingStock.get());
@@ -247,7 +236,7 @@ public class ModelRailwaySimulation {
      * @param id identifier of the rolling stock to find
      * @return the specified rolling stock
      */
-    public Optional<RollingStock> getRollingStock(String id) {
+    private Optional<RollingStock> getRollingStock(String id) {
         if (Coach.IDENTIFIER_PATTERN.matcher(id).matches()) {
             final int coachId = Integer.parseInt(id.substring(1));
             return Optional.ofNullable(coaches.get(coachId));

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

@@ -1,5 +1,10 @@
 package edu.kit.informatik.ui;
 
+import edu.kit.informatik.model.Coach;
+import edu.kit.informatik.model.FreightCoach;
+import edu.kit.informatik.model.PassengerCoach;
+import edu.kit.informatik.model.SpecialCoach;
+
 /**
  * Type of a coach.
  *
@@ -21,8 +26,36 @@ public enum CoachType {
     SPECIAL;
 
     /**
-     * Parse the textual representation of a coach type into the correct enum value.
+     * Regex to match one coach type.
+     */
+    public static final String COACH_TYPE = "passenger|freight|special";
+
+    /**
+     * Create a coach of this type with the specified parameters.
      *
+     * @param id coach identifier
+     * @param length coach length
+     * @param couplingFront whether the coach should have a front coupling
+     * @param couplingBack whether the coach should have a back coupling
+     * @return new coach
+     * @throws InvalidInputException on invalid input (e.g. zero-sized coach)
+     */
+    public Coach createCoach(int id, int length, boolean couplingFront, boolean couplingBack)
+            throws InvalidInputException {
+        switch (this) {
+            case PASSENGER:
+                return new PassengerCoach(id, length, couplingFront, couplingBack);
+            case FREIGHT:
+                return new FreightCoach(id, length, couplingFront, couplingBack);
+            case SPECIAL:
+                return new SpecialCoach(id, length, couplingFront, couplingBack);
+            default:
+                throw new IllegalArgumentException("this is null");
+        }
+    }
+
+    /**
+     * Parse the textual representation of a coach type into the correct enum value.
      * @param value coach type as text
      * @return coach type as enum, or null if invalid
      */

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

@@ -1,5 +1,10 @@
 package edu.kit.informatik.ui;
 
+import edu.kit.informatik.model.DieselEngine;
+import edu.kit.informatik.model.ElectricalEngine;
+import edu.kit.informatik.model.Engine;
+import edu.kit.informatik.model.SteamEngine;
+
 /**
  * Type of locomotive. Can be either diesel, steam or electrical.
  *
@@ -20,6 +25,36 @@ public enum EngineType {
      */
     ELECTRICAL;
 
+    /**
+     * Regex to match one engine type.
+     */
+    public static final String ENGINE_TYPE = "diesel|steam|electrical";
+
+    /**
+     * Create a new engine of this type and the specified parameters.
+
+     * @param series engine series/class
+     * @param name engine name
+     * @param length engine length
+     * @param couplingFront whether the engine should have a front coupling
+     * @param couplingBack whether the engine should have a back coupling
+     * @return new engine
+     * @throws InvalidInputException on invalid input (e.g. zero-sized engine)
+     */
+    public Engine createEngine(String series, String name, int length, boolean couplingFront, boolean couplingBack)
+            throws InvalidInputException {
+        switch (this) {
+            case ELECTRICAL:
+                return new ElectricalEngine(series, name, length, couplingFront, couplingBack);
+            case STEAM:
+                return new SteamEngine(series, name, length, couplingFront, couplingBack);
+            case DIESEL:
+                return new DieselEngine(series, name, length, couplingFront, couplingBack);
+            default:
+                throw new IllegalStateException("this is null");
+        }
+    }
+
     /**
      * Parse the textual representation of a engine type into the correct enum value.
      *

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

@@ -8,7 +8,7 @@ import edu.kit.informatik.ui.InvalidInputException;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
-import static edu.kit.informatik.model.Coach.COACH_TYPE;
+import static edu.kit.informatik.ui.CoachType.COACH_TYPE;
 import static edu.kit.informatik.ui.command.CommandFactory.BOOL;
 import static edu.kit.informatik.ui.command.CommandFactory.CREATE_COACH;
 import static edu.kit.informatik.ui.command.CommandFactory.NUMBER;

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

@@ -2,17 +2,15 @@ package edu.kit.informatik.ui.command;
 
 import edu.kit.informatik.Terminal;
 import edu.kit.informatik.model.Coach;
-import edu.kit.informatik.model.DieselEngine;
-import edu.kit.informatik.model.ElectricalEngine;
 import edu.kit.informatik.model.Engine;
 import edu.kit.informatik.model.ModelRailwaySimulation;
-import edu.kit.informatik.model.SteamEngine;
 import edu.kit.informatik.ui.EngineType;
 import edu.kit.informatik.ui.InvalidInputException;
 
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
+import static edu.kit.informatik.ui.EngineType.ENGINE_TYPE;
 import static edu.kit.informatik.ui.command.CommandFactory.ALPHANUMERIC_WORD;
 import static edu.kit.informatik.ui.command.CommandFactory.BOOL;
 import static edu.kit.informatik.ui.command.CommandFactory.CREATE_ENGINE;
@@ -26,7 +24,7 @@ import static edu.kit.informatik.ui.command.CommandFactory.NUMBER;
  */
 public class CreateEngine extends Command {
     private static final Pattern CREATE_ENGINE_ARGUMENTS
-            = Pattern.compile(" (electrical|diesel|steam) (" + ALPHANUMERIC_WORD + ") (" + ALPHANUMERIC_WORD + ") ("
+            = Pattern.compile(" (" + ENGINE_TYPE + ") (" + ALPHANUMERIC_WORD + ") (" + ALPHANUMERIC_WORD + ") ("
             + NUMBER + ") (" + BOOL + ") (" + BOOL + ")");
 
     /**
@@ -59,20 +57,7 @@ public class CreateEngine extends Command {
         if (type == null) {
             throw new IllegalStateException("command not initialized");
         }
-        final Engine engine;
+        final Engine engine = type.createEngine(series, name, length, couplingFront, couplingBack);
-        switch (type) {
-            case ELECTRICAL:
-                engine = new ElectricalEngine(series, name, length, couplingFront, couplingBack);
-                break;
-            case STEAM:
-                engine = new SteamEngine(series, name, length, couplingFront, couplingBack);
-                break;
-            case DIESEL:
-                engine = new DieselEngine(series, name, length, couplingFront, couplingBack);
-                break;
-            default:
-                throw new IllegalStateException("command not initialized");
-        }
         simulation.createEngine(engine);
         Terminal.printLine(engine.getIdentifier());
     }