2주차 - Step3 로또(2등) 리뷰 부탁드립니다. (#249)

* [step3] refactor : step3 패키지 생성, ResultSheet 객체 생성

* [step3] refactor : 셔플링 테스트 제거

* [step3] refactor : 로또 결과를 담는 Map에 각 등수에 해당하는 당첨로또티켓의 갯수를 담도록 수정

* [step3] refactor : 결과를 담는 ResultSheet 객체에 총 수익 계산하는 메서드 추가

* [step3] refactor : 결과를 담는 ResultSheet 객체에 구매한 복권 개수 반환하는 메서드 추가

* [step3] refactor : step2 피드백 반영 마무리

* [step3] feat : 2등과 3등 분리 로직 추가 (실험적)

* [step3] refactor : 2등 출력 메서드 수정, 무의미한 변수 제거

* [step3] refactor : 총 수익률 계산 오류 수정

* [step3] refactor : 로또 결과 출력 로직 수정

Author: Integerous

src/main/java/step3/LottoApplication.java

@@ -0,0 +1,29 @@
+package step3;
+
+import step3.domain.LottoSeller;
+import step3.domain.LottoTicket;
+import step3.domain.ResultSheet;
+import step3.view.InputView;
+import step3.view.OutputView;
+
+import java.util.List;
+
+public class LottoApplication {
+
+    public static void main(String[] args) {
+        final int inputMoney = InputView.askMoneyToInput();
+        final int numberOfTicketsToBuy = LottoSeller.countLottoTickets(inputMoney);
+
+        OutputView.printNumberOfTickets(numberOfTicketsToBuy);
+
+        List<LottoTicket> lottoTickets = LottoSeller.issueLottoTicket(numberOfTicketsToBuy);
+        OutputView.printLottoTickets(lottoTickets);
+
+        LottoTicket luckyNumber = LottoSeller.getLuckyNumber(InputView.askLuckyNumber());
+        int bonusNumber = InputView.askBonusNumber();
+
+        ResultSheet result = ResultSheet.getResult(lottoTickets, luckyNumber, bonusNumber);
+        OutputView.printResult(result);
+    }
+}
+

src/main/java/step3/domain/LottoBalls.java

@@ -0,0 +1,17 @@
+package step3.domain;
+
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+
+public class LottoBalls {
+
+    private static List<Integer> lottoBalls = IntStream
+            .rangeClosed(LottoNumber.MINIMUM_LOTTO_NUMBER, LottoNumber.MAXIMUM_LOTTO_NUMBER)
+            .boxed()
+            .collect(Collectors.toList());
+
+    public static List<Integer> getLottoBalls() {
+        return lottoBalls;
+    }
+}

src/main/java/step3/domain/LottoNumber.java

@@ -0,0 +1,47 @@
+package step3.domain;
+
+import java.util.Objects;
+
+public class LottoNumber {
+    static final String ALERT_OUT_OF_RANGE_OF_LOTTO_NUMBER = "로또번호는 1부터 45까지의 자연수만 가능합니다.";
+    static final int MINIMUM_LOTTO_NUMBER = 1;
+    static final int MAXIMUM_LOTTO_NUMBER = 45;
+    private int number;
+
+    private LottoNumber(int number) {
+        if (isOutOfRange(number)) {
+            throw new IllegalArgumentException(ALERT_OUT_OF_RANGE_OF_LOTTO_NUMBER);
+        }
+        this.number = number;
+    }
+
+    public static LottoNumber from(Integer number) {
+        return new LottoNumber(number);
+    }
+
+    private boolean isOutOfRange(int number) {
+        return number < MINIMUM_LOTTO_NUMBER || number > MAXIMUM_LOTTO_NUMBER;
+    }
+
+    public int getNumber() {
+        return number;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        LottoNumber that = (LottoNumber) o;
+        return number == that.number;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(number);
+    }
+
+    @Override
+    public String toString() {
+        return number + "";
+    }
+}

src/main/java/step3/domain/LottoRank.java

@@ -0,0 +1,43 @@
+package step3.domain;
+
+import java.util.Arrays;
+
+public enum LottoRank {
+
+    FIRST_PLACE(6, 2_000_000_000),
+    SECOND_PLACE(5, 30_000_000),
+    THIRD_PLACE(5, 1_500_000),
+    FOURTH_PLACE(4, 50_000),
+    FIFTH_PLACE(3, 5_000),
+    LOSER(0, 0);
+
+    private int numberOfMatchedToLuckyNumber;
+    private int prizeMoney;
+
+    LottoRank(int numberOfMatchedToLuckyNumber, int prizeMoney) {
+        this.numberOfMatchedToLuckyNumber = numberOfMatchedToLuckyNumber;
+        this.prizeMoney = prizeMoney;
+    }
+
+    public static LottoRank from(int countMatchedNumbers, boolean isMatchedToBonusNumber) {
+        if ((countMatchedNumbers == SECOND_PLACE.numberOfMatchedToLuckyNumber) && isMatchedToBonusNumber) {
+            return Arrays.stream(LottoRank.values())
+                    .filter(lottoRank -> lottoRank.prizeMoney == SECOND_PLACE.prizeMoney)
+                    .findFirst()
+                    .get();
+        }
+        return Arrays.stream(LottoRank.values())
+                .filter(lottoRank -> lottoRank.numberOfMatchedToLuckyNumber == countMatchedNumbers)
+                .findFirst()
+                .orElse(LOSER);
+    }
+
+    public int getNumberOfMatchingNumber() {
+        return numberOfMatchedToLuckyNumber;
+    }
+
+    public int getPrizeMoney() {
+        return prizeMoney;
+    }
+
+}

src/main/java/step3/domain/LottoSeller.java

@@ -0,0 +1,37 @@
+package step3.domain;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class LottoSeller {
+    static final int PRICE_OF_A_LOTTO_TICKET = 1000;
+    static final String ALERT_MISSING_MONEY = "돈을 넣어주세요. 로또복권은 한 장당 1000원 입니다.";
+
+    public static int countLottoTickets(int inputMoney) {
+        validationInputMoney(inputMoney);
+        return inputMoney / PRICE_OF_A_LOTTO_TICKET;
+    }
+
+    public static List<LottoTicket> issueLottoTicket(int numberOfTicketsToBuy) {
+        List<LottoTicket> lottoTickets = new ArrayList<>();
+
+        for (int i = 0; i < numberOfTicketsToBuy; i++) {
+            lottoTickets.add(LottoTicketGenerator.issue());
+        }
+        return lottoTickets;
+    }
+
+    public static LottoTicket getLuckyNumber(List<Integer> inputLuckyNumber) {
+        List<LottoNumber> lottoTicket = inputLuckyNumber.stream()
+                .map(LottoNumber::from)
+                .collect(Collectors.toList());
+        return LottoTicketGenerator.issue(lottoTicket);
+    }
+
+    private static void validationInputMoney(int inputMoney) {
+        if (inputMoney < PRICE_OF_A_LOTTO_TICKET) {
+            throw new IllegalArgumentException(ALERT_MISSING_MONEY);
+        }
+    }
+}

src/main/java/step3/domain/LottoTicket.java

@@ -0,0 +1,71 @@
+package step3.domain;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.Objects;
+
+public class LottoTicket {
+    static final String ALERT_NUMBER_OVERLAP = "중복된 로또 번호가 존재합니다.";
+    static final String AlERT_DIFFERENT_SIZE_OF_NUMBERS = "로또번호의 개수가 6개가 아닙니다.";
+
+    private final List<LottoNumber> lottoTicket;
+
+    LottoTicket(List<LottoNumber> lottoTicket) {
+        validationNumberSize(lottoTicket);
+        validationNumberOverlap(lottoTicket);
+        this.lottoTicket = lottoTicket;
+    }
+
+    public int getNumberOfMatchedToLuckyNumber(LottoTicket luckyNumber) {
+        return (int) luckyNumber.getLottoTicket().stream()
+                .filter(lottoTicket::contains)
+                .count();
+    }
+
+    boolean isBonusNumberMatched(int bonusNumber) {
+        return lottoTicket.stream()
+                .mapToInt(LottoNumber::getNumber)
+                .anyMatch(i -> i == bonusNumber);
+    }
+
+    private void validationNumberSize(List<LottoNumber> lottoTicket) {
+        if (lottoTicket.size() != LottoTicketGenerator.BASIC_LOTTO_SIZE) {
+            throw new IllegalArgumentException(AlERT_DIFFERENT_SIZE_OF_NUMBERS);
+        }
+    }
+
+    private void validationNumberOverlap(List<LottoNumber> lottoTicket) {
+        long SizeOfLottoTicket = lottoTicket.stream()
+                .mapToLong(LottoNumber::getNumber)
+                .distinct()
+                .count();
+
+        if (SizeOfLottoTicket != LottoTicketGenerator.BASIC_LOTTO_SIZE) {
+            throw new IllegalArgumentException(ALERT_NUMBER_OVERLAP);
+        }
+    }
+
+    public List<LottoNumber> getLottoTicket() {
+        return Collections.unmodifiableList(lottoTicket);
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        LottoTicket that = (LottoTicket) o;
+        return Objects.equals(lottoTicket, that.lottoTicket);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(lottoTicket);
+    }
+
+    @Override
+    public String toString() {
+        return "LottoTicket{" +
+                "lottoTicket=" + lottoTicket +
+                '}';
+    }
+}

src/main/java/step3/domain/LottoTicketGenerator.java

@@ -0,0 +1,31 @@
+package step3.domain;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class LottoTicketGenerator {
+    static final int BASIC_LOTTO_SIZE = 6;
+
+    static LottoTicket issue() {
+        return new LottoTicket(pickLottoBalls(LottoBalls.getLottoBalls()));
+    }
+
+    static LottoTicket issue(List<LottoNumber> lottoTicket) {
+        return new LottoTicket(lottoTicket);
+    }
+
+    static List<LottoNumber> pickLottoBalls(List<Integer> lottoBalls) {
+        shuffleLottoBalls(lottoBalls);
+        return lottoBalls.stream()
+                .limit(BASIC_LOTTO_SIZE)
+                .sorted()
+                .map(LottoNumber::from)
+                .collect(Collectors.toList());
+    }
+
+    static void shuffleLottoBalls(List<Integer> lottoBalls) {
+        Collections.shuffle(lottoBalls);
+    }
+
+}

src/main/java/step3/domain/ResultSheet.java

@@ -0,0 +1,60 @@
+package step3.domain;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+public class ResultSheet {
+    private static final int LOTTO_TICKET_PRICE = 1000;
+
+    private Map<LottoRank, Integer> resultSheet;
+
+    private ResultSheet(Map<LottoRank, Integer> resultSheet) {
+        this.resultSheet = resultSheet;
+    }
+
+    public static ResultSheet getResult(List<LottoTicket> lottoTickets, LottoTicket luckyNumber, int bonusNumber) {
+        Map<LottoRank, Integer> lottoResultMap = new HashMap<>();
+
+        for (LottoTicket ticket : lottoTickets) {
+            LottoRank lottoRank = LottoRank.from(ticket.getNumberOfMatchedToLuckyNumber(luckyNumber), ticket.isBonusNumberMatched(bonusNumber));
+            int numberOfTicketsCorrespondingToRank = lottoResultMap.getOrDefault(lottoRank, 0);
+            lottoResultMap.put(lottoRank, ++numberOfTicketsCorrespondingToRank);
+        }
+        return new ResultSheet(lottoResultMap);
+    }
+
+    private int getTotalTicketsBought() {
+        return resultSheet.values()
+                .stream()
+                .reduce(Integer::sum)
+                .get();
+    }
+
+    private int totalMoneySpentForTickets() {
+        return getTotalTicketsBought() * LOTTO_TICKET_PRICE;
+    }
+
+    private int getNumberOfTicketsCorrespondingToRank(LottoRank lottoRank) {
+        return resultSheet.getOrDefault(lottoRank, 0);
+    }
+
+    private int getEachPrizeMoney(LottoRank lottoRank) {
+        return lottoRank.getPrizeMoney() * this.getNumberOfTicketsCorrespondingToRank(lottoRank);
+    }
+
+    private int getTotalPrizeMoney() {
+        return resultSheet.keySet()
+                .stream()
+                .mapToInt(this::getEachPrizeMoney)
+                .sum();
+    }
+
+    public double getEarningRate() {
+        return getTotalPrizeMoney() / totalMoneySpentForTickets();
+    }
+
+    public Map<LottoRank, Integer> getResultMap() {
+        return resultSheet;
+    }
+}

src/main/java/step3/view/InputView.java

@@ -0,0 +1,39 @@
+package step3.view;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Scanner;
+import java.util.stream.Collectors;
+
+public class InputView {
+    private static final String LUCKY_NUMBER_SEPARATOR = ",";
+    private static Scanner scanner = new Scanner(System.in);
+
+    public static int askMoneyToInput() {
+        System.out.println("구입금액을 입력해 주세요.");
+        return scanner.nextInt();
+    }
+
+    public static List<Integer> askLuckyNumber() {
+        printBlackLine();
+        scanner.nextLine();
+        System.out.println("지난 주 당첨 번호를 입력해주세요.");
+        String inputLuckyNumber = scanner.nextLine();
+        printBlackLine();
+
+        return Arrays.stream(inputLuckyNumber.split(LUCKY_NUMBER_SEPARATOR))
+                .map(String::trim)
+                .mapToInt(Integer::parseInt)
+                .boxed()
+                .collect(Collectors.toList());
+    }
+
+    public static int askBonusNumber() {
+        System.out.println("보너스 볼을 입력해 주세요.");
+        return scanner.nextInt();
+    }
+
+    private static void printBlackLine() {
+        System.out.println();
+    }
+}