万年历

/**
 * 日历类
 * @author FuJianshi
 *
 */
public class Calendar {
	
	private int year; //年
	private int month; //月

	/**
	 * 打印日历
	 */
	public void print(){
		//按照日历格式打印
		int days = getDays(year,month);
		
		int weeks = getWeeks(year,month);
		
		System.out.println("星期日\t星期一\t星期二\t星期三\t星期四\t星期五\t星期六");
		for(int j = 1; j <= weeks; j++){
			System.out.print("\t");
	
		}
		for (int i = 1; i <= days; i++) {
			
			System.out.print( i + "\t");
			if((i + weeks) % 7 == 0){
				System.out.println();
			}
		}
		
	}
	
	/**
	 * 获取当前月的天数
	 */
	public int getDays(int year, int month){
		int[] daysOfmonth = {0,31,28,31,30,31,30,31,31,30,31,30,31};
		int days = daysOfmonth[month];
		if(isBigYear(year) && month == 2){
			return days + 1;
		}else{
			return days;
		}
	}
	
	
	/**
	 * 判断闰年
	 */
	public boolean isBigYear(int year){
		if(year % 4 == 0 && year % 100 != 0 || year % 400 == 0){
			return true;
		}else{
			return false;
		}
	}
	
	/**
	 * 判断当前年到1970年中间隔了多少天
	 */
	public int getWeeks(int year,int month){
		int days = (year - 1970) * 365;
		for(int i = 1970; i < year;i++){
			if(isBigYear(i)){
				days ++;
			}
		}
		for(int i = 1; i < month; i++){
			days += getDays(year,i);
		}
		return (days + 3) % 7 + 1;
	}
}

测试

public static void main(String[] args) {
		Calendar c = new Calendar();
		c.year = 2018;
		c.month = 11;
		c.print();
}