[그리디] 김하은 로또 미션 1,2단계 제출합니다.

src/main/java/lotto/Application.java

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+package lotto;
+
+public class Application {
+    public static void main(String[] args) {
+        LottoGame lottoGame = new LottoGame();
+        lottoGame.run(); // static이 아닌 메서드를 호출!
+    }
+}

src/main/java/lotto/LottoGame.java

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+package lotto;
+
+import lotto.domain.*;
+import lotto.view.InputView;
+import lotto.view.OutputView;
+
+import java.util.List;
+
+public class LottoGame {
+    private static final int LOTTO_PRICE = 1000;
+
+    public void run() {
+        int money = Integer.parseInt(InputView.inputMoney());
+        LottoTickets tickets = purchase(money);
+        OutputView.printTickets(tickets);
+
+        Lotto winningLotto = askWinningLotto();
+        showResult(tickets, winningLotto, money);
+    }
+
+    private LottoTickets purchase(int money) {
+        int count = money / LOTTO_PRICE;
+        OutputView.printTicketCount(count);
+        return LottoTickets.generate(count);
+    }
+
+    private Lotto askWinningLotto() {
+        String input = InputView.inputWinningNumbers();
+        List<Integer> numbers = java.util.Arrays.stream(input.split(","))
+                .map(String::trim)
+                .map(Integer::parseInt)
+                .collect(java.util.stream.Collectors.toList());
+        return Lotto.from(numbers);
+    }
+
+    private void showResult(LottoTickets tickets, Lotto winningLotto, int money) {
+        LottoResult lottoResult = new LottoResult(tickets.matchAll(winningLotto));
+        double yield = lottoResult.calculateYield(money);
+
+        OutputView.printStatistics(lottoResult.getResult(), yield);
+    }
+}

src/main/java/lotto/domain/Lotto.java

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+package lotto.domain;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class Lotto {
+    private static final int LOTTO_SIZE = 6;
+    private final List<LottoNumber> numbers;
+
+    private Lotto(List<LottoNumber> numbers) {
+        validate(numbers);
+        this.numbers = new ArrayList<>(numbers);
+        Collections.sort(this.numbers);
+    }
+
+    public static Lotto from(List<Integer> numbers) {
+        List<LottoNumber> lottoNumbers = numbers.stream()
+                .map(LottoNumber::new)
+                .collect(Collectors.toList());
+        return new Lotto(lottoNumbers);
+    }
+
+    private void validate(List<LottoNumber> numbers) {
+        if (numbers.size() != LOTTO_SIZE) {
+            throw new IllegalArgumentException("로또 번호는 6개여야 합니다.");
+        }
+    }
+
+    public int countMatch(Lotto winningLotto) {
+        return (int) numbers.stream()
+                .filter(winningLotto.numbers::contains)
+                .count();
+    }
+
+    @Override
+    public String toString() {
+        return numbers.toString();
+    }
+}

src/main/java/lotto/domain/LottoNumber.java

@@ -0,0 +1,55 @@
+package lotto.domain;
+
+import java.util.Objects;
+//자바는 integer의 비교 방법은 이미 알고 있지만, 우리는 LottoNumber을 객체로 만들어서
+//관리하고 있기 때문에, 비교 방법에 대해서 알려줘야 한다. > comparable<LottoNumber>
+public class LottoNumber implements Comparable<LottoNumber> {
+    private static final int MIN_NUMBER = 1;
+    private static final int MAX_NUMBER = 45;
+    private final int number;
+
+    public LottoNumber(int number) {
+        validate(number);
+        this.number = number;
+    }
+
+    private void validate(int number) {
+        if (number < MIN_NUMBER || number > MAX_NUMBER) {
+            throw new IllegalArgumentException("로또 번호는 1~45 사이여야 합니다.");
+        }
+    }
+
+    //모든 클래스는 자동으로 boolean equals, haseCode, toString을 상속한다.
+    //그러므로 LottoNumber도 이미 가지고 있음
+    //우리가 다시 override하는 이유는, 기본 equals는 주소 비교여서다. 우리가 원하는 것은
+    //값이 같으면 같은 객체로 두게끔이다. 그래서 override해서 수정한다.
+    //equals가 같으면 hashCode도 같아야 하므로 같이 수정.
+
+    @Override
+    public boolean equals(Object o) {//주소가 같아야 동일한게 아니라, 숫자가 같으면 동일함을 알려주기 위한 메서드
+        if (this == o) return true;
+        //getClass는 해당 객체의 타입을 알려주는 메서드
+        if (o == null || getClass() != o.getClass()) return false;
+        //if문 다 통과했으니 o는 null이 아니고 o의 클래스가 LottoNumber과 같다고 볼 수 있음
+        LottoNumber that = (LottoNumber) o; //형변환. o는 object지만 LottoNumber임에 틀림없으니 형변환을 해준다
+        //that에 저장
+        return number == that.number; //boolean이므로 같으면 true를 다르면 false를 반환함
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(number);
+    }
+
+    //compareTo : 정렬 순서가 오름차순임을 알려줌. Integer.compare 하기 때문
+    @Override
+    public int compareTo(LottoNumber other) {
+        return Integer.compare(this.number, other.number);
+    }
+
+    //toString으로 바꿔주지 않는다면 LottoNumber 객체를 출력했을 때 주소값이 출력됨
+    @Override
+    public String toString() {
+        return String.valueOf(number);
+    }
+}

src/main/java/lotto/domain/LottoResult.java

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+package lotto.domain;
+import java.util.EnumMap;
+import java.util.Map;
+
+public class LottoResult {
+    private final Map<Rank, Long> result;
+
+    public LottoResult(Map<Rank, Long> result) {
+        this.result = new EnumMap<>(result);
+    }
+
+    public double calculateYield(int investment) {
+        long totalPrize = result.entrySet().stream()
+                .mapToLong(entry -> entry.getKey().getWinningMoney() * entry.getValue())
+                .sum();
+        return (double) totalPrize / investment;
+    }
+
+    public Map<Rank, Long> getResult() {
+        return result;
+    }
+}

src/main/java/lotto/domain/LottoTickets.java

@@ -0,0 +1,41 @@
+package lotto.domain;
+
+import java.util.Collections;
+import java.util.EnumMap;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+
+public class LottoTickets {
+    private final List<Lotto> tickets;
+
+    public LottoTickets(List<Lotto> tickets) {
+        this.tickets = tickets;
+    }
+
+    public static LottoTickets generate(int count) {
+        List<Integer> allNumbers = IntStream.rangeClosed(1, 45).boxed().collect(Collectors.toList());
+        List<Lotto> tickets = IntStream.range(0, count)
+                .mapToObj(i -> {
+                    Collections.shuffle(allNumbers);
+                    return Lotto.from(allNumbers.subList(0, 6));
+                })
+                .collect(Collectors.toList());
+        return new LottoTickets(tickets);
+    }
+
+    public Map<Rank, Long> matchAll(Lotto winningLotto) {
+        return tickets.stream()
+                .map(ticket -> Rank.valueOf(ticket.countMatch(winningLotto)))
+                .collect(Collectors.groupingBy(rank -> rank, () -> new EnumMap<>(Rank.class), Collectors.counting()));
+    }
+
+    public List<Lotto> getTickets() {
+        return tickets;
+    }
+
+    public int size() {
+        return tickets.size();
+    }
+}

src/main/java/lotto/domain/Rank.java

@@ -0,0 +1,34 @@
+package lotto.domain;
+
+import java.util.Arrays;
+
+public enum Rank {
+    MISS(0, 0),
+    FIFTH(3, 5_000),
+    FOURTH(4, 50_000),
+    THIRD(5, 1_500_000),
+    FIRST(6, 2_000_000_000);
+
+    private final int matchCount;
+    private final int winningMoney;
+
+    Rank(int matchCount, int winningMoney) {
+        this.matchCount = matchCount;
+        this.winningMoney = winningMoney;
+    }
+
+    public static Rank valueOf(int matchCount) {
+        return Arrays.stream(values())
+                .filter(rank -> rank.matchCount == matchCount)
+                .findFirst()
+                .orElse(MISS);
+    }
+
+    public int getMatchCount() {
+        return matchCount;
+    }
+
+    public int getWinningMoney() {
+        return winningMoney;
+    }
+}

src/main/java/lotto/view/InputView.java

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+package lotto.view;
+
+import java.util.Scanner;
+
+public class InputView {
+    private static final Scanner scanner = new Scanner(System.in);
+
+    public static String inputMoney() {
+        System.out.println("구입금액을 입력해 주세요.");
+        return scanner.nextLine();
+    }
+
+    public static String inputWinningNumbers() {
+        System.out.println("지난 주 당첨 번호를 입력해 주세요.");
+        return scanner.nextLine();
+    }
+}

src/main/java/lotto/view/OutputView.java

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+package lotto.view;
+
+import lotto.domain.Lotto;
+import lotto.domain.LottoTickets;
+import lotto.domain.Rank;
+import java.util.List;
+import java.util.Map;
+
+public class OutputView {
+    public static void printTicketCount(int count) {
+        System.out.println("\n" + count + "개를 구매했습니다.");
+    }
+
+    public static void printTickets(LottoTickets tickets) {
+        for (Lotto ticket : tickets.getTickets()) {
+            System.out.println(ticket);
+        }
+        System.out.println();
+    }
+
+    public static void printStatistics(Map<Rank, Long> result, double yield) {
+        System.out.println("\n당첨 통계\n---------");
+        printRank(Rank.FIFTH, result.getOrDefault(Rank.FIFTH, 0L));
+        printRank(Rank.FOURTH, result.getOrDefault(Rank.FOURTH, 0L));
+        printRank(Rank.THIRD, result.getOrDefault(Rank.THIRD, 0L));
+        printRank(Rank.FIRST, result.getOrDefault(Rank.FIRST, 0L));
+        System.out.printf("총 수익률은 %.2f입니다.\n", yield);
+    }
+
+    private static void printRank(Rank rank, long count) {
+        System.out.printf("%d개 일치 (%d원)- %d개\n",
+                rank.getMatchCount(), rank.getWinningMoney(), count);
+    }
+}

src/test/java/lotto/domain/LottoNumberTest.java

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+package lotto.domain;
+
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+class LottoNumberTest {
+
+    @ParameterizedTest
+    @ValueSource(ints = {0, 46, -1})
+    @DisplayName("로또 번호가 1~45 범위를 벗어나면 예외가 발생한다.")
+    void invalidNumberRange(int number) {
+        assertThatThrownBy(() -> new LottoNumber(number))
+                .isInstanceOf(IllegalArgumentException.class)
+                .hasMessage("로또 번호는 1~45 사이여야 합니다.");
+    }
+}

src/test/java/lotto/domain/LottoTest.java

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+package lotto.domain;
+
+import org.junit.jupiter.api.DisplayNameGeneration;
+import org.junit.jupiter.api.DisplayNameGenerator;
+import org.junit.jupiter.api.Test;
+import java.util.Arrays;
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+@SuppressWarnings("NonAsciiCharacters")
+@DisplayNameGeneration(DisplayNameGenerator.ReplaceUnderscores.class)
+class LottoTest {
+
+    @Test
+    void 로또_번호가_6개가_아니면_예외가_발생한다() {
+        // given
+        List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5);
+
+        assertThatThrownBy(() -> Lotto.from(numbers))
+                .isInstanceOf(IllegalArgumentException.class);
+    }
+
+    @Test
+    void 당첨_번호와_몇_개의_번호가_일치하는지_계산한다() {
+        Lotto ticket = Lotto.from(Arrays.asList(1, 2, 3, 4, 5, 6));
+        Lotto winningLotto = Lotto.from(Arrays.asList(1, 2, 3, 10, 11, 12));
+
+        int matchCount = ticket.countMatch(winningLotto);
+        assertThat(matchCount).isEqualTo(3);
+    }
+}

src/test/java/lotto/domain/RankTest.java

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+package lotto.domain;
+
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class RankTest {
+
+    @Test
+    @DisplayName("일치 개수에 따라 올바른 Rank를 반환한다.")
+    void valueOfTest() {
+        assertThat(Rank.valueOf(6)).isEqualTo(Rank.FIRST);
+        assertThat(Rank.valueOf(3)).isEqualTo(Rank.FIFTH);
+        assertThat(Rank.valueOf(0)).isEqualTo(Rank.MISS);
+    }
+}