Test3.java

/*
 * 김소은
 * 과제3. 놀이동산 입장권 계산 프로그램
 *
 * 입장권과 관련된 상수, 변수, 함수를 묶어 클래스를 만들었습니다.
 * 입력값이 잘못됐으면 재입력할 수 있도록 구현하였습니다.
 */

import java.util.InputMismatchException;
import java.util.Scanner;

class AmusementParkTicket {
	private static final int BASIC_ENTRANCE_FEE = 10000;			// 기본 입장료
	private static final int GENERAL_DISCOUNT_ENTRANCE_FEE = 8000;	// 일반 할인 입장료
	private static final int SPECIAL_DISCOUNT_ENTRANCE_FEE = 4000;	// 특별 할인 입장료

	private static final int BABY_AGE = 3;
	private static final int CHILD_AGE = 13;
	private static final int AFTER_HOUR = 17;

	private final int age;
	private final int admissionHour;
	private final char nationalMerit;
	private final char welfareCard;

	public static void checkValidAge(int age) {
		if (age < 0) {
			throw new InputMismatchException("나이는 0 이상의 값이어야 합니다.");
		}
	}

	public static void checkValidHour(int hour) {
		if (hour < 0 || hour > 23) {
			throw new InputMismatchException("시간은 0 ~ 23 사이의 값이어야 합니다.");
		}
	}

	public static void checkValidYN(char value) {
		if (value != 'y' && value != 'n') {
			throw new InputMismatchException("y 또는 n만 입력 가능합니다.");
		}
	}
	
	public AmusementParkTicket(int age, int admissionHour, char nationalMerit, char welfareCard) {
		this.age = age;
		this.admissionHour = admissionHour;
		this.nationalMerit = nationalMerit;
		this.welfareCard = welfareCard;
	}
	
	public void printEntranceFee() {
		System.out.printf("입장료: %d", calculateEntranceFee());
	}

	public int calculateEntranceFee() {
		if (age < BABY_AGE) {
			return 0;
		}

		if (age < CHILD_AGE || admissionHour >= AFTER_HOUR) {
			return GENERAL_DISCOUNT_ENTRANCE_FEE;
		}

		if (nationalMerit == 'y' || welfareCard == 'y') {
			return SPECIAL_DISCOUNT_ENTRANCE_FEE;
		}

		return BASIC_ENTRANCE_FEE;
	}
}

public class Test3 {
	private static final Scanner scanner = new Scanner(System.in);

	public static void main(String[] args) {
		System.out.println("[입장권 계산]");

		AmusementParkTicket amusementParkTicket = inputAmusementParkTicket();
		amusementParkTicket.printEntranceFee();

		closeResource();
	}

	private static AmusementParkTicket inputAmusementParkTicket() {
		int age = inputAge();
		int admissionHour = inputAdmissionHour();
		char nationalMerit = inputNationalMerit();
		char welfareCard = inputWelfareCard();

		return new AmusementParkTicket(age, admissionHour, nationalMerit, welfareCard);
	}

	private static int inputAge() {
		int age = 0;
		boolean isValid = false;

		while (! isValid) {
			System.out.print("나이를 입력해 주세요.(숫자):");

			try {
				checkIntType();

				age = scanner.nextInt();
				AmusementParkTicket.checkValidAge(age);

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

		return age;
	}

	private static int inputAdmissionHour() {
		int admissionHour = 0;
		boolean isValid = false;

		while (! isValid) {
			System.out.print("입장시간을 입력해 주세요.(24-hour):");

			try {
				checkIntType();

				admissionHour = scanner.nextInt();
				AmusementParkTicket.checkValidHour(admissionHour);

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

		return admissionHour;
	}

	private static char inputNationalMerit() {
		char nationalMerit = '-';
		boolean isValid = false;

		while (! isValid) {
			System.out.print("국가유공자 여부를 입력해 주세요.(y/n):");

			try {
				nationalMerit = scanner.next().charAt(0);
				AmusementParkTicket.checkValidYN(nationalMerit);

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

		return nationalMerit;
	}

	private static char inputWelfareCard() {
		char inputDescription = '-';
		boolean isValid = false;

		while (! isValid) {
			System.out.print("복지카드 여부를 입력해 주세요.(y/n):");

			try {
				inputDescription = scanner.next().charAt(0);
				AmusementParkTicket.checkValidYN(inputDescription);

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

		return inputDescription;
	}

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

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

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