주민번호 생성기

miniProject01\createid.java

/*
 작성자: 고지민
*/
//주민번호 생성기
import java.util.*;
public class Main {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        int year =input_int("출생년도를 입력해 주세요.(yyyy):",input,1975,2100);
        int month=input_int("출생월을 입력해 주세요.(mm):",input,1,12);
        int day=input_day("출생일을 입력해 주세요.(dd):",input,1,31, year,month);
        char gender=input_char("성별을 입력해주세요.(m/f):",input);
        output_id(year,month,day,gender);
    }
    public static int input_int(String message,Scanner input,int min, int max){
        try{
            System.out.print(message);
            int value = input.nextInt();
            if (value<min||value>max){
                throw new Exception();
            }
            return value;
        }catch (Exception e){
            System.out.println("다시입력해주세요");
            return input_int(message,input,min,max);
        }
    }
    public static int input_day(String message,Scanner input,int min,int max,int year,int month){ // day 인경우 month에 따라 최대값 제한
        int max_day;
        int[] even_month={4,6,9,11};
        if(month==2){
            max_day= isLeap(year) ? 29:28;
        } else{
            max_day=Arrays.asList(even_month).contains(month) ? 30:31;
        }

        try{
            System.out.print(message);
            int value = input.nextInt();
            if (value<min||value>max_day){
                throw new Exception();
            }
            return value;
        }catch (Exception e){
            System.out.println("다시입력해주세요");
            return input_int(message,input,min,max_day);
        }
    }
    public static char input_char(String message,Scanner input){
        try{
            System.out.print(message);
            char value = input.next().charAt(0);
            if(value!='m'||value!='f'){
                return value;
            }
            throw new Exception();
        }catch (Exception e){
            System.out.println("다시입력해주세요");
            return input_char(message,input);
        }
    }
    public static boolean isLeap(int year){ // 윤년 체크
        return (year%4==0&&year%100!=0)||year%400==0;
    }
    public static void output_id(int year,int month,int day, char gender){ //주민번호 생성및 출력
        StringBuilder id= new StringBuilder();

        id.append(year % 100);
        id.append(String.format("%02d", month));
        id.append(String.format("%02d", day));
        id.append("-");
        id.append(rightNumber(year,gender));
        System.out.println(id);
    }
    public static StringBuilder rightNumber(int year, char gender){ //주민번호 오른쪽 자리생성
        int firstNum;
        Random rnd =new Random();
        if (year<2000){
            firstNum = gender=='m' ? 1:2;
        }else{
            firstNum = gender=='m'? 3:4;
        }
        StringBuilder number = new StringBuilder();
        number.append(firstNum);
        while(number.length()<7){
            number.append(rnd.nextInt(10));
        }
        return number;
    }

}