📖 Calendar

💻 Calendar EX.날짜 getter, setter

		//Calendar cal = new GregorianCalendar();
		Calendar cal = Calendar.getInstance(); //이 방법을 더 많이 사용
		
		//오늘 날짜 취득 (getter)
		int year = cal.get(Calendar.YEAR);
		int month = cal.get(Calendar.MONTH) + 1;
		int day = cal.get(Calendar.DATE);
		
		System.out.println(year + "/" + month + "/" + day);
		
		// 날짜 셋팅 (setter)
		cal.set(Calendar.YEAR, 2023);
		cal.set(Calendar.MONTH, 3 - 1);
		cal.set(Calendar.DATE, 16);
		
		System.out.println(year + "/" + month + "/" + day);

💻 Calendar EX.달력만들기

package sample19;

import java.util.Calendar;

public class MainClass {

	public static void main(String[] args) {
		
		Calendar cal = Calendar.getInstance(); //이 방법을 더 많이 사용
		
		//오늘 날짜 취득 (getter)
		int year = cal.get(Calendar.YEAR);
		int month = cal.get(Calendar.MONTH) + 1;
		int day = cal.get(Calendar.DATE);
		
		System.out.println(year + "/" + month + "/" + day);
	
		//오전/오후
		String ampm = cal.get(Calendar.AM_PM) == 0 ? "오전":"오후";
		System.out.println(ampm);
		
        //요일
		int weekday = cal.get(Calendar.DAY_OF_WEEK);// 일(1) ~ 토(7)
		System.out.println(weekday);
		
		switch(weekday) {
			case 1:
				System.out.println("일요일");
				break;
			case 2:
				System.out.println("월요일");
				break;
			case 3:
				System.out.println("화요일");
				break;
			case 4:
				System.out.println("수요일");
				break;
			case 5:
				System.out.println("목요일");
				break;
			case 6:
				System.out.println("금요일");
				break;
			case 7:
				System.out.println("토요일");
				break;
		}
		//cal.set(Calendar.YEAR, 2023);
		//cal.set(Calendar.MONTH, 1 - 1);
		
		//지정 달의 마지막 날(28, 29, 30, 31)
		int lastday = cal.getActualMaximum(Calendar.DAY_OF_MONTH);
		System.out.println(lastday);
		
		//위의 빈칸
		cal.set(Calendar.DATE, 1);
		weekday = cal.get(Calendar.DAY_OF_WEEK);
		
		int upEmpty = (weekday - 1) % 7;
		System.out.println("위의 빈칸의 수 : " + upEmpty);
				
		//아래 빈칸
		lastday = cal.getActualMaximum(Calendar.DAY_OF_MONTH);
		cal.set(Calendar.DATE, lastday); //12/31
		
		weekday = cal.get(Calendar.DAY_OF_WEEK);
		int downEmpty = 7 - weekday;
		System.out.println("밑의 빈칸의 수 : " + downEmpty);
		
        //함수출력
		calendarPrint(1995, 9);
	}
    
    // 달력만들기 함수
		static void calendarPrint(int year, int month) {
			Calendar cal = Calendar.getInstance();
			cal.set(Calendar.YEAR, year);
			cal.set(Calendar.MONTH, month -1);
			cal.set(Calendar.DATE, 1);
			
			int startDay = cal.get(Calendar.DAY_OF_WEEK); //1~7
			int lastDay = cal.getActualMaximum(Calendar.DAY_OF_MONTH);
			
			year = cal.get(Calendar.YEAR);
			month = cal.get(Calendar.MONTH) + 1;
			
			System.out.println(year + "년" + month + "월");
			System.out.println("==========================================================");
			
			String week_day = "일월화수목금토";
			for (int i = 0; i < week_day.length(); i++) {
				char c = week_day.charAt(i);
				System.out.print(c + "\t");
				
			}
			System.out.println();
			System.out.println("==========================================================");
			
			//위쪽빈칸
			for(int i = 1; i < startDay; i++) {
				System.out.print("*" + "\t");
			}
			
			//날짜
			int _day = 1;
			for(int i = 0; i < lastDay; i++) {
				System.out.print(_day + "\t");
				
				if((_day + startDay - 1)% 7 == 0) {
					System.out.println();
				}
				
				
				_day++;
			}
			
			//밑쪽빈칸
			for(int i = 0; i < 7 - (startDay + lastDay - 1) % 7; i++) {
				System.out.print("*" + "\t");
			}
			System.out.println();
			System.out.println("==========================================================");
		}

}