🚀 5단계 - 자동차 경주(리팩토링)

src/main/java/com/racing/Main.java

@@ -1,11 +1,12 @@
 package com.racing;
 
 import com.racing.domain.Car;
+import com.racing.domain.Cars;
 import com.racing.ui.InputView;
 import com.racing.ui.ResultView;
 import com.racing.utils.CarHelper;
+import com.racing.utils.RacingHelper;
 
-import java.util.ArrayList;
 import java.util.List;
 
 public class Main {
@@ -15,34 +16,40 @@ public static void main(String[] args) {
 
         List<String> validCarNames = CarHelper.splitCarName(carNames);
 
-        List<Car> carList = createCars(validCarNames);
-        runRace(carList, tryNumber);
+        Cars cars = createCars(validCarNames);
 
-        List<Car> winners = CarHelper.determineWinners(carList);
+        runRace(cars, tryNumber);
+
+        Cars winners =
+                cars.determineWinners();
         ResultView.printWinners(winners);
     }
 
-    private static List<Car> createCars(List<String> carNames) {
-        List<Car> carList = new ArrayList<>();
+    private static Cars createCars(List<String> carNames) {
+        Cars cars = new Cars();
 
         for (String carName : carNames) {
-            carList.add(new Car(0, carName));
+            cars.addCars(new Car(0, carName));
         }
 
-        return carList;
+        return cars;
     }
 
-    private static void runRace(List<Car> carList, int tryNumber) {
+    private static void runRace(Cars cars, int tryNumber) {
         ResultView.printStartMessage();
         for (int i = 0; i < tryNumber; i++) {
-            moveAllCars(carList);
-            ResultView.printRoundResult(i + 1, carList);
+            moveAllCars(cars);
+
+            int roundNumber = i + 1;
+            ResultView.printRoundResult(roundNumber, cars);
         }
     }
 
-    private static void moveAllCars(List<Car> carList) {
-        for (Car car : carList) {
-            car.move();
+    private static void moveAllCars(Cars cars) {
+        RacingHelper racingHelper = new RacingHelper();
+
+        for (Car car : cars.getCarList()) {
+            car.move(racingHelper.shouldMove());
         }
     }
 }

src/main/java/com/racing/domain/Car.java

@@ -1,48 +1,40 @@
 package com.racing.domain;
 
-import com.racing.utils.RacingHelper;
-
 public class Car {
 
-    private int state = 0;
-    private String name;
+    private Position position;
+    private CarName carName;
 
     // 기본 생성자
     public Car() {
         this(0, ""); // 기본값 0으로 다른 생성자 호출
     }
 
     // 상태 지정 생성자
-    public Car(int state, String name) {
-        this.state = state;
-        this.name = name;
+    public Car(int position, String carName) {
+        this.position = new Position(position);
+        this.carName = new CarName(carName);
     }
 
-    public void move() {
-        RacingHelper racingHelper = new RacingHelper();
-
-        if (racingHelper.shouldMove()) {
-            state++;
+    public void move(boolean isMovable) {
+        if (isMovable) {
+            position.addPosition();
         }
     }
 
-    public String displayRacingState() {
-        return displayCarName() + " : " + displayState();
-    }
-
-    public String displayState() {
-        return "-".repeat(state);
+    public String displayRacingPosition() {
+        return carName.getCarName() + " : " + position.displayDashAsPosition();
     }
 
     public String displayCarName() {
-        return name;
+        return carName.getCarName();
     }
 
-    public int getState() {
-        return state;
+    public int getPosition() {
+        return position.getPosition();
     }
 
     public boolean isDefeated(int verseState) {
-        return state < verseState;
+        return position.isBiggerThanPosition(verseState);
     }
 }

src/main/java/com/racing/domain/CarName.java

@@ -0,0 +1,32 @@
+package com.racing.domain;
+
+import java.util.Objects;
+
+public class CarName {
+    private final String carName;
+
+    public CarName(String carName) {
+        if (carName == null || carName.trim().isEmpty()) {
+            throw new IllegalArgumentException("Car name cannot be empty or blank.");
+        }
+
+        this.carName = carName;
+    }
+
+    public String getCarName() {
+        return carName;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        CarName carName1 = (CarName) o;
+        return Objects.equals(carName, carName1.carName);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hashCode(carName);
+    }
+}

src/main/java/com/racing/domain/Cars.java

@@ -0,0 +1,76 @@
+package com.racing.domain;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Objects;
+import java.util.stream.Collectors;
+
+public class Cars {
+    List<Car> carList;
+
+    public Cars() {
+        carList = new ArrayList<>();
+    }
+
+    public Cars(List<Car> carList) {
+        this.carList = carList;
+    }
+
+    public void addCars(Car car) {
+        carList.add(car);
+    }
+
+    public List<Car> getCarList() {
+        return this.carList;
+    }
+
+    public int findMaxPosition() {
+        int maxPosition = 0;
+        for (Car car : this.carList) {
+            maxPosition = car.isDefeated(maxPosition) ? maxPosition : car.getPosition();
+        }
+
+        return maxPosition;
+    }
+
+    public Cars determineWinners() {
+        int maxPosition = this.findMaxPosition();
+
+        List<Car> winnerList = this.carList.stream()
+                .filter(car -> car.getPosition() == maxPosition)
+                .collect(Collectors.toList());
+
+        return new Cars(winnerList);
+    }
+
+    public int carsSize() {
+        return this.carList.size();
+    }
+
+    public String getCarName(int index) {
+        if (index < 0 || index >= carList.size()) {
+            throw new IndexOutOfBoundsException("Invalid car index");
+        }
+
+        return carList.get(index).displayCarName();
+    }
+
+    public void printRacingPositions() {
+        for (Car car : carList) {
+            System.out.println(car.displayRacingPosition());
+        }
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        Cars cars = (Cars) o;
+        return Objects.equals(carList, cars.carList);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hashCode(carList);
+    }
+}

src/main/java/com/racing/domain/Position.java

@@ -0,0 +1,44 @@
+package com.racing.domain;
+
+import java.util.Objects;
+
+public class Position {
+    private int position;
+
+    public Position() {
+        this(0);
+    }
+
+    public Position(int position) {
+        this.position = position;
+    }
+
+    public void addPosition() {
+        this.position++;
+    }
+
+    public int getPosition() {
+        return position;
+    }
+
+    public String displayDashAsPosition() {
+        return "-".repeat(this.position);
+    }
+
+    public boolean isBiggerThanPosition(int number) {
+        return this.position < number;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        Position position1 = (Position) o;
+        return position == position1.position;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hashCode(position);
+    }
+}

src/main/java/com/racing/ui/ResultView.java

@@ -1,27 +1,25 @@
 package com.racing.ui;
 
-import com.racing.domain.Car;
-
-import java.util.List;
+import com.racing.domain.Cars;
 
 public class ResultView {
     public static void printStartMessage() {
         System.out.println("실행 결과");
     }
 
-    public static void printRoundResult(int round, List<Car> carList) {
+    public static void printRoundResult(int round, Cars cars) {
         System.out.println("# " + round + "회차");
-        for (Car car : carList) {
-            System.out.println(car.displayRacingState());
-        }
+
+        cars.printRacingPositions();
+
         System.out.println();
     }
 
-    public static void printWinners(List<Car> winners) {
+    public static void printWinners(Cars winners) {
         System.out.print("최종 우승자: ");
-        int winnerSize = winners.size();
+        int winnerSize = winners.carsSize();
         for (int i = 0; i < winnerSize; i++) {
-            System.out.print(winners.get(i).displayCarName());
+            System.out.print(winners.getCarName(i));
             printComma(i < winnerSize - 1);
         }
 

src/main/java/com/racing/utils/CarHelper.java

@@ -1,7 +1,5 @@
 package com.racing.utils;
 
-import com.racing.domain.Car;
-
 import java.util.ArrayList;
 import java.util.List;
 
@@ -28,39 +26,12 @@ private static void addIfValid(String carName, List<String> validNames) {
         }
     }
 
-    public static boolean isValidCarName(String carName) {
+    private static boolean isValidCarName(String carName) {
         if (carName.isEmpty()) {
             return false;
         }
 
         return carName.length() < VALID_CAR_NAME;
     }
 
-    public static List<Car> determineWinners(List<Car> carList) {
-        List<Car> winners = new ArrayList<>();
-        int maxState = findMaxState(carList);
-
-        for (Car car : carList) {
-            addWinners(car, maxState, winners);
-        }
-
-        return winners;
-    }
-
-    private static void addWinners(Car car, int maxState, List<Car> winners) {
-        if (car.getState() == maxState) {
-            winners.add(car);
-        }
-    }
-
-    private static int findMaxState(List<Car> carList) {
-        int maxState = 0;
-        for (Car car : carList) {
-            maxState = car.isDefeated(maxState) ? maxState : car.getState();
-
-        }
-
-        return maxState;
-    }
-
 }

src/main/java/com/racing/utils/RacingHelper.java

@@ -5,7 +5,7 @@
 /**
  * 레이싱에서 사용 할 헬퍼 메서드를 모아놓은 클래스
  */
-public class RacingHelper implements RandomMover {
+public class RacingHelper implements RandomStrategy {
     private static final int RANDOM_NUMBER_RANGE = 10;
     private static final int FORWARD_MINIMUM_NUMBER = 4;
 

src/main/java/com/racing/utils/RandomMover.java → src/main/java/com/racing/utils/RandomStrategy.java

@@ -1,5 +1,5 @@
 package com.racing.utils;
 
-public interface RandomMover {
+public interface RandomStrategy {
     public boolean shouldMove();
 }