java实现日历

import java.text.DateFormatSymbols;
import java.util.Calendar;
import java.util.GregorianCalendar;

//日历测试
public class CalenderTest {

	public static void main(String[] args) {
		//声明并创建日历对象
		GregorianCalendar calendar = new GregorianCalendar();
		
		//获取  日 月 
		int today = calendar.get(Calendar.DAY_OF_MONTH);
		
		int month = calendar.get(Calendar.MONTH);
		
		//将calendar设置这个月的第一天
		calendar.set(Calendar.DAY_OF_MONTH, 1);
		
		//获取
		int weekday = calendar.get(Calendar.DAY_OF_WEEK);
		
		//获取一周的起始日期
		int firstDayOfWeek = calendar.getFirstDayOfWeek();
		
		int indent = 0 ;
		
		while (weekday != firstDayOfWeek) {
			indent++ ;
			calendar.add(Calendar.DAY_OF_MONTH, -1);
			weekday = calendar.get(Calendar.DAY_OF_WEEK);
			
		}
		
		//打印这周的名称
		String[] weekdayNames = new DateFormatSymbols().getShortWeekdays();
		
		do {
			System.out.printf("%4s",weekdayNames[weekday]);
			
			calendar.add(Calendar.DAY_OF_MONTH, 1);
			
			weekday = calendar.get(Calendar.DAY_OF_WEEK);
			
		} while (weekday != firstDayOfWeek);
		
		System.out.println();
		
		for (int i = 0; i <= indent ; i++) {
			System.out.print("    ");
		}
		
		calendar.set(Calendar.DAY_OF_MONTH, 1);
		
		do {
			//打印 天
			int day = calendar.get(Calendar.DAY_OF_MONTH);
			System.out.printf("%3d",day);
			
			if (day == today) {
				System.out.print("*");
			}else {
				System.out.print("  ");
			}
			
			calendar.add(Calendar.DAY_OF_MONTH, 1);
			
			weekday = calendar.get(Calendar.DAY_OF_WEEK);
			
			if (weekday == firstDayOfWeek) {
				System.out.println();
			}
		} while (calendar.get(Calendar.MONTH) == month);
		
		if (weekday == firstDayOfWeek) {
			System.out.println();
		}
		
	}
}