Step4

build.gradle

@@ -1,4 +1,6 @@
 plugins {
+    id 'org.springframework.boot' version '2.5.4'
+    id 'io.spring.dependency-management' version '1.0.11.RELEASE'
     id 'java'
 }
 

src/main/java/racing/controller/CarRacingController.java

@@ -0,0 +1,28 @@
+package racing.controller;
+
+import racing.entity.Car;
+import racing.service.Cars;
+import racing.view.InputView;
+import racing.view.ResultView;
+
+import java.util.List;
+
+public class CarRacingController {
+
+    public static void main(String[] args) {
+        InputView inputView = new InputView();
+        List<Car> cars = inputView.inputCar();
+        int rounds = inputView.inputNumber();
+
+        Cars racingService = new Cars(cars);
+        ResultView resultView = new ResultView();
+
+        for (int i = 0; i < rounds; i++) {
+            racingService.moveCars();
+            resultView.printResult(racingService.getCars());
+        }
+        resultView.findWinners(racingService.findWinners());
+    }
+}
+
+

src/main/java/racing/entity/Car.java

@@ -0,0 +1,40 @@
+package racing.entity;
+
+import java.util.Random;
+
+public class Car {
+
+    private final String name;
+    protected int position;
+    private final Random random = new Random();
+
+    private static final int MOVE_THRESHOLD = 4;
+    private static final int RANDOM_RANGE = 10;
+
+    public Car(String name) {
+        this.name = name;
+        this.position = 0;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public int getPosition() {
+        return position;
+    }
+
+    public void move() {
+        if (canMove()) {
+            position += 1;
+        }
+    }
+
+    protected boolean canMove() {
+        int randomValue = random.nextInt(RANDOM_RANGE);
+        return randomValue >= MOVE_THRESHOLD;
+    }
+}
+
+
+

src/main/java/racing/service/Cars.java

@@ -0,0 +1,36 @@
+package racing.service;
+
+import racing.entity.Car;
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class Cars {
+
+    private final List<Car> cars;
+
+    public Cars(List<Car> cars) {
+        this.cars = cars;
+    }
+
+    public void moveCars() {
+        for (Car car : cars) {
+            car.move();
+        }
+    }
+
+    public List<Car> getCars() {
+        return cars;
+    }
+
+    public List<Car> findWinners() {
+        int maxPosition = cars.stream()
+                .mapToInt(Car::getPosition)
+                .max()
+                .orElse(0);
+
+        return cars.stream()
+                .filter(car -> car.getPosition() == maxPosition)
+                .collect(Collectors.toList());
+    }
+}
+

src/main/java/racing/view/InputView.java

@@ -0,0 +1,27 @@
+package racing.view;
+
+import racing.entity.Car;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Scanner;
+
+public class InputView {
+
+    private final Scanner scanner = new Scanner(System.in);
+
+    public List<Car> inputCar() {
+        System.out.println("경주할 자동차 이름을 입력하세요.(이름은 쉼표(,) 기준으로 구분)");
+        String[] names = scanner.nextLine().split(",");
+        List<Car> cars = new ArrayList<>();
+        for (String name : names) {
+            cars.add(new Car(name.trim()));
+        }
+        return cars;
+    }
+
+    public int inputNumber() {
+        System.out.println("시도할 횟수를 입력하세요 : ");
+        return scanner.nextInt();
+    }
+}
+

src/main/java/racing/view/ResultView.java

@@ -0,0 +1,34 @@
+package racing.view;
+
+import racing.entity.Car;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class ResultView {
+    public void printResult(List<Car> cars) {
+        StringBuilder result = new StringBuilder();
+        cars.forEach(car -> result.append(buildCarResult(car)).append("\n"));
+        System.out.println(result.toString());
+    }
+
+    private String buildCarResult(Car car) {
+        return car.getName() + ": " + carPosition(car.getPosition());
+    }
+
+    private String carPosition(int position) {
+        StringBuilder stringBuilder = new StringBuilder();
+        for (int i = 0; i < position; i++) {
+            stringBuilder.append("-");
+        }
+        return stringBuilder.toString();
+    }
+
+    public void findWinners(List<Car> winners) {
+        String winnerNames = winners.stream()
+                .map(Car::getName)
+                .collect(Collectors.joining(", "));
+        System.out.println("우승자는 " + winnerNames + " 입니다.");
+    }
+}
+

src/test/java/racing/CarTest.java

@@ -0,0 +1,41 @@
+package racing;
+
+import org.junit.jupiter.api.Test;
+import racing.entity.Car;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class CarTest {
+
+    @Test
+    void carMoves() {
+        Car car = new Car("Car");
+        car.move();
+        assertEquals(1, car.getPosition());
+    }
+
+    @Test
+    void carDoesNotMove() {
+        Car car = new Car("CarzCar") {
+            @Override
+            public void move() {
+                if (!canMove()) {
+                    position = 0;
+                }
+            }
+        };
+        car.move();
+        assertEquals(0, car.getPosition());
+    }
+
+    @Test
+    void carNameIsSetCorrectly() {
+        Car car = new Car("Car");
+        assertEquals("Car", car.getName());
+    }
+
+    @Test
+    void carInitialPositionIsZero() {
+        Car car = new Car("Car");
+        assertEquals(0, car.getPosition());
+    }
+}

src/test/java/racing/CarsTest.java

@@ -0,0 +1,35 @@
+package racing;
+
+import org.junit.jupiter.api.Test;
+import racing.entity.Car;
+import racing.service.Cars;
+import java.util.Arrays;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class CarsTest {
+
+    @Test
+    void testMoveCars() {
+        Car car1 = new Car("Car1");
+        Car car2 = new Car("Car2");
+        Cars racingService = new Cars(Arrays.asList(car1, car2));
+
+        int initialPositionCar1 = car1.getPosition();
+        int initialPositionCar2 = car2.getPosition();
+
+        racingService.moveCars();
+
+        assertEquals(calculateExpectedPosition(initialPositionCar1, car1.getPosition()), car1.getPosition());
+        assertEquals(calculateExpectedPosition(initialPositionCar2, car2.getPosition()), car2.getPosition());
+    }
+
+
+    private int calculateExpectedPosition(int initialPosition, int currentPosition) {
+        if (currentPosition > initialPosition) {
+            return initialPosition + 1;
+        }
+        return initialPosition;
+    }
+
+}
+