獲取當月的日曆

                                    獲取當月的日曆

package com.day;

import java.util.Calendar;

public class HelloWorld {
	public static void main(String[] args) {
		Calendar calendar = Calendar.getInstance();
		int year = calendar.get(Calendar.YEAR);
		int month = calendar.get(Calendar.MONTH) + 1;
		boolean flag = false;
		int beforDay = 0;
		int days = 0;
		int nowday = 0;
		if ((year % 4 == 0 && year % 100 != 0) || (year % 400 == 0)) {
			flag = true;
		} else {
			flag = false;
		}

		for (int i = 1900; i < year; i++) {
			if ((i % 4 == 0 && i % 100 != 0) || (i % 400 == 0)) {
				beforDay += 366;
			} else {
				beforDay += 365;
			}
		}
		for (int i = 1; i <= month; i++) {
			switch (i) {
			case 1:
			case 3:
			case 5:
			case 7:
			case 8:
			case 10:
			case 12:
				if (i == month) {
					nowday = 31;
				} else {
					days += 31;
				}
				break;
			case 2:
				if (flag) {
					if (i == month) {
						nowday = 29;
					} else {
						days += 29;// 閏年
					}
				} else {
					if (i == month) {
						nowday = 28;
					} else {
						days += 28;// 平年
					}
				}
				break;
			case 4:
			case 6:
			case 9:
			case 11:
				if (i == month) {
					nowday = 31;
				} else {
					days += 30;
				}
				break;
			default:
				break;
			}
		}
		int beforDays = beforDay + days;
		int m = beforDays % 7;
		System.out.println("-----------" + year + "-" + month + "日曆信息 ------------");
		System.out.println("星期一\t星期二\t星期三\t星期四\t星期五\t星期六\t星期日");
		for (int i = 0; i < m; i++) {
			System.out.print("\t");
		}
		for (int i = 1; i <= nowday; i++) {
			if ((i + m) % 7 == 0) {
				System.out.println(i);
			} else {
				System.out.print(i + "\t");
			}
		}

	}
}