JavaStudy04.java

/* 
 김정훈
 2023-06-02 | 주민등록번호 생성 프로그램
*/
import java.util.Random;
import java.util.Scanner;

public class JavaStudy04 {
    public static void main(String[] args) {
        System.out.println("[주민등록번호 계산]");

        String nationalIdentifyNumber = "";
        Random random = new Random();
        StringBuilder sb = new StringBuilder();

        System.out.print("출생년도를 입력해 주세요.(yyyy):");
        Scanner sc = new Scanner(System.in);
        String birthYear = sc.next();
        if(!birthYear.matches("[0-9]+")) return;
        if (Integer.parseInt(birthYear) < 2020 || birthYear.length() > 4) {
            return;
        }
        sb.append(birthYear.substring(2,4));

        System.out.print("출생월을 입력해 주세요.(mm):");
        sc = new Scanner(System.in);
        String birthMonth = sc.next();
        if(!birthMonth.matches("[0-9]+")) return;
        if(Integer.parseInt(birthMonth) > 12 || Integer.parseInt(birthMonth) < 1) {
            return;
        }
        String strMonth = (birthMonth.length()==1) ? String.format("%02d", birthMonth) : birthMonth;
        sb.append(strMonth);

        System.out.print("출생일을 입력해 주세요.(dd):");
        sc = new Scanner(System.in);
        String birthDay = sc.next();
        if(!birthDay.matches("[0-9]+")) {
            return;
        }
        if(Integer.parseInt(birthDay) > 31 || Integer.parseInt(birthDay) < 1) {
            return;
        }

        String strDay = (birthDay.length()==1) ? String.format("%02d", birthDay) : birthDay;
        sb.append(strDay);

        sb.append("-");

        System.out.print("성별을 입력해 주세요.(m/f):");
        sc = new Scanner(System.in);
        String strSex = sc.next().toLowerCase();
        if (strSex.length() != 1 || (!strSex.contains("m") && !strSex.contains("f"))) {
            return;
        }

        int sex = (strSex.equals("f")) ? 4 : 3;
        sb.append(sex);

        sb.append(String.format("%06d", random.nextInt(1, 999999)));
        nationalIdentifyNumber = new String(sb);
        System.out.println(nationalIdentifyNumber); //nationalIdentifyNumber;
    }
}