近日老要跑系统日志，每次发生问题要遍历每日的情况。代码改了好几次，每次输入的日期变化，都要修改不少代码。于是写了个日期类来调用。
包含以下功能
1.判断是否为闰年
2.判断一个月有几天
3.得出两个日期直接所有日期

package com.javaer.common;import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;/*** java时间类* * @author mc2* */
public class JTime {static String dateFormat = "yyyy-MM-dd";static SimpleDateFormat format = new SimpleDateFormat(dateFormat);/*** 获取两个日期之间所有的日期* @param date1* @param date2* @return*/public static ArrayList days(String date1, String date2) {ArrayList L = new ArrayList();if (date1.equals(date2)) {System.out.println("两个日期相等!");return L;}String tmp;if (date1.compareTo(date2) > 0) { // 确保 date1的日期不晚于date2tmp = date1;date1 = date2;date2 = tmp;}tmp = format.format(str2Date(date1).getTime() + 3600 * 24 * 1000);int num = 0;while (tmp.compareTo(date2) < 0) {L.add(tmp);num++;tmp = format.format(str2Date(tmp).getTime() + 3600 * 24 * 1000);}if (num == 0)System.out.println("两个日期相邻!");return L;}private static Date str2Date(String str) {if (str == null)return null;try {return format.parse(str);} catch (ParseException e) {e.printStackTrace();}return null;}/*** 判断是否闰年* * @param year* @return*/public static boolean isLeapYear(int year) {return (year % 400 == 0) || ((year % 4 == 0) && (year % 100 != 0));}/*** 一个月有几天* * @param year* @param month* @return*/public static int dayInMonth(int year, int month) {boolean yearleap = isLeapYear(year);int day;if (yearleap && month == 2) {day = 29;} else if (!yearleap && month == 2) {day = 28;} else if (month == 4 || month == 6 || month == 9 || month == 11) {day = 30;} else {day = 31;}return day;}/*** @param args*/public static void main(String[] args) {JTime jt = new JTime();System.out.println(jt.days("2012-02-02", "2012-03-23"));}}

结果

[2012-02-03, 2012-02-04, 2012-02-05, 2012-02-06, 2012-02-07, 2012-02-08, 2012-02-09, 2012-02-10, 2012-02-11, 2012-02-12, 2012-02-13, 2012-02-14, 2012-02-15, 2012-02-16, 2012-02-17, 2012-02-18, 2012-02-19, 2012-02-20, 2012-02-21, 2012-02-22, 2012-02-23, 2012-02-24, 2012-02-25, 2012-02-26, 2012-02-27, 2012-02-28, 2012-02-29, 2012-03-01, 2012-03-02, 2012-03-03, 2012-03-04, 2012-03-05, 2012-03-06, 2012-03-07, 2012-03-08, 2012-03-09, 2012-03-10, 2012-03-11, 2012-03-12, 2012-03-13, 2012-03-14, 2012-03-15, 2012-03-16, 2012-03-17, 2012-03-18, 2012-03-19, 2012-03-20, 2012-03-21, 2012-03-22]

首发于http://java-er.com - http://java-er.com/blog/java-time-days/