Test7.java

/*
 * 김소은
 * 과제7. 로또 당첨 프로그램
 * 
 * 6개의 로또 번호와 관련된 변수, 함수를 묶어 클래스를 만들었습니다.
 * 입력값이 잘못됐으면 재입력할 수 있도록 구현하였습니다.
 */

import java.util.ArrayList;
import java.util.HashSet;
import java.util.InputMismatchException;
import java.util.List;
import java.util.Random;
import java.util.Scanner;
import java.util.stream.Collectors;

class LotterySerial {
	private final List<Integer> lotteryNumbers;

	public LotterySerial() {
		lotteryNumbers = createLotteryNumbers();
	}

	private List<Integer> createLotteryNumbers() {
		Random random = new Random();
		HashSet<Integer> lotteryNumberSet = new HashSet<>();

		while (lotteryNumberSet.size() < 6) {
			int lotteryNumber = random.nextInt(45) + 1;
			lotteryNumberSet.add(lotteryNumber);
		}

		return lotteryNumberSet.stream().sorted().collect(Collectors.toList());
	}

	public int countMatchingNumber(LotterySerial winningLotterySerial) {
		int count = 0;
		for (int winningNumber : winningLotterySerial.lotteryNumbers) {
			for (int myNumber : lotteryNumbers) {
				if (winningNumber == myNumber) {
					count++;
				}
			}
		}
		return count;
	}

	@Override
	public String toString() {
		StringBuilder sb = new StringBuilder();

		lotteryNumbers
				.forEach(lotteryNumber -> sb.append(String.format("%02d", lotteryNumber)).append(","));
		sb.deleteCharAt(sb.length() - 1);

		return sb.toString();
	}
}

public class Test7 {
	private static final ArrayList<LotterySerial> myLotterySerials = new ArrayList<>();
	private static LotterySerial winningLotterySerial;
	private static Scanner scanner;

	public static void main(String[] args) {
		scanner = new Scanner(System.in);

		System.out.println("[로또 당첨 프로그램]");

		int num = inputLotteryNumber();

		printMyLotterySerials(num);

		System.out.println("[로또 발표]");
		printWinningSerial();

		System.out.println("[내 로또 결과]");
		printMyLotterySerialsResult();

		closeResource();
	}

	private static int inputLotteryNumber() {
		int num = 0;
		boolean isValid = false;

		while (! isValid) {
			System.out.print("로또 개수를 입력해 주세요.(숫자 1 ~ 10):");

			try {
				checkIntType();

				num = scanner.nextInt();
				checkValidLotteryNumber(num);

				isValid = true;
			} catch (InputMismatchException e) {
				System.out.println(e.getMessage());
			}
		}

		return num;
	}

	private static void checkIntType() {
		if (! scanner.hasNextInt()) {
			removeBuffer();
			throw new InputMismatchException("숫자만 입력 가능합니다.");
		}
	}

	private static void removeBuffer() { scanner.next(); }

	private static void checkValidLotteryNumber(int lotteryNumber) {
		if (lotteryNumber < 1 || lotteryNumber > 10) {
			throw new InputMismatchException("로또 개수는 1 ~ 10 사이어야 합니다.");
		}
	}

	private static void printMyLotterySerials(int num) {
		StringBuilder sb = new StringBuilder();

		for (int idx = 0; idx < num; idx++) {
			LotterySerial lotterySerial = new LotterySerial();
			myLotterySerials.add(lotterySerial);

			sb.append(toStringIndexAndLotterySerial(idx, lotterySerial));
			sb.append("\n");
		}

		System.out.println(sb);
	}

	private static void printWinningSerial() {
		winningLotterySerial = new LotterySerial();

		System.out.println("\t" + winningLotterySerial + "\n");
	}

	private static void printMyLotterySerialsResult() {
		StringBuilder sb = new StringBuilder();

		for (int idx = 0; idx < myLotterySerials.size(); idx++) {
			LotterySerial lotterySerial = myLotterySerials.get(idx);

			sb.append(toStringIndexAndLotterySerial(idx, lotterySerial));

			int count = lotterySerial.countMatchingNumber(winningLotterySerial);
			sb.append(toStringMatchingResultFormat(count));

			sb.append("\n");
		}

		System.out.println(sb);
	}

	private static String toStringMatchingResultFormat(int count) {
		return String.format(" => %d개 일치", count);
	}

	private static String toStringIndexAndLotterySerial(int idx, LotterySerial lotterySerial) {
		return toStringAlphabetFormat(idx) + lotterySerial;
	}

	private static String toStringAlphabetFormat(int idx) {
		return String.format("%c\t", (char) ('A' + idx));
	}

	private static void closeResource() { scanner.close(); }
}