web開發中公用元件的開發之一---------DateUtils
在web應用中我們經常要到用到對日期的操作
已經有很多的開原始碼供選擇，例如apache 就有
不是太複雜就是不太適合中國國情的，反正專案中很少用到apache的公用元件包
下面是我在web開發中常用的些方法操作
現簡單列舉出來，已示記念。
Java程式碼
package com.chinadim.test.utils;
import java.text.ParsePosition;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
/**
* xxxxx
* xxxxxx
*/
public class DateUtils {
/**
* 靜態常量
*/
public static final String C_TIME_PATTON_DEFAULT = "yyyy-MM-dd HH:mm:ss";
public static final String C_DATE_PATTON_DEFAULT = "yyyy-MM-dd";
public static final int C_ONE_SECOND = 1000;
public static final int C_ONE_MINUTE = 60 * C_ONE_SECOND;
public static final long C_ONE_HOUR = 60 * C_ONE_MINUTE;
public static final long C_ONE_DAY = 24 * C_ONE_HOUR;
/**
* 計算當前月份的最大天數
* @return
*/
public static int findMaxDayInMonth() {
return findMaxDayInMonth(0, 0);
}
/**
* 計算指定日期月份的最大天數
* @param date
* @return
*/
public static int findMaxDayInMonth(Date date) {
if (date == null) {
return 0;
}
return findMaxDayInMonth(date2Calendar(date));
}
/**
* 計算指定日曆月份的最大天數
* @param calendar
* @return
*/
public static int findMaxDayInMonth(Calendar calendar) {
if (calendar == null) {
return 0;
}
return calendar.getActualMaximum(Calendar.DAY_OF_MONTH);
}
/**
* 計算當前年某月份的最大天數
* @param month
* @return
*/
public static int findMaxDayInMonth(int month) {
return findMaxDayInMonth(0, month);
}
/**
* 計算某年某月份的最大天數
* @param year
* @param month
* @return
*/
public static int findMaxDayInMonth(int year, int month) {
Calendar calendar = Calendar.getInstance();
if (year > 0) {
calendar.set(Calendar.YEAR, year);
}
if (month > 0) {
calendar.set(Calendar.MONTH, month - 1);
}
return findMaxDayInMonth(calendar);
}
/**
* Calendar 轉換為 Date
* @param calendar
* @return
*/
public static Date calendar2Date(Calendar calendar) {
if (calendar == null) {
return null;
}
return calendar.getTime();
}
/**
* Date 轉換為 Calendar
* @param date
* @return
*/
public static Calendar date2Calendar(Date date) {
if (date == null) {
return null;
}
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
return calendar;
}
/**
* 拿到預設格式的SimpleDateFormat
* @return
*/
public static SimpleDateFormat getSimpleDateFormat() {
return getSimpleDateFormat(null);
}
/**
* 拿到指定輸出格式的SimpleDateFormat
* @param format
* @return
*/
public static SimpleDateFormat getSimpleDateFormat(String format) {
SimpleDateFormat sdf;
if (format == null) {
sdf = new SimpleDateFormat(C_TIME_PATTON_DEFAULT);
} else {
sdf = new SimpleDateFormat(format);
}
return sdf;
}
/**
* 轉換當前時間為預設格式
* @return
*/
public static String formatDate2Str() {
return formatDate2Str(new Date());
}
/**
* 轉換指定時間為預設格式
* @param date
* @return
*/
public static String formatDate2Str(Date date) {
return formatDate2Str(date, C_TIME_PATTON_DEFAULT);
}
/**
* 轉換指定時間為指定格式
* @param date
* @param format
* @return
*/
public static String formatDate2Str(Date date, String format) {
if (date == null) {
return null;
}
if (format == null || format.equals("")) {
format = C_TIME_PATTON_DEFAULT;
}
SimpleDateFormat sdf = getSimpleDateFormat(format);
return sdf.format(date);
}
/**
* 轉換預設格式的時間為Date
* @param dateStr
* @return
*/
public static Date formatStr2Date(String dateStr) {
return formatStr2Date(dateStr, null);
}
/**
* 轉換指定格式的時間為Date
* @param dateStr
* @param format
* @return
*/
public static Date formatStr2Date(String dateStr, String format) {
if (dateStr == null) {
return null;
}
if (format == null || format.equals("")) {
format = C_TIME_PATTON_DEFAULT;
}
SimpleDateFormat sdf = getSimpleDateFormat(format);
return sdf.parse(dateStr, new ParsePosition(0));
}
/**
* 轉換預設格式的時間為指定格式時間
* @param dateStr
* @param defineFormat
* @return
*/
public static String formatDefault2Define(String dateStr, String defineFormat) {
return formatSource2Target(dateStr, C_TIME_PATTON_DEFAULT, defineFormat);
}
/**
* 轉換源格式的時間為目標格式時間
* @param dateStr
* @param sourceFormat
* @param targetFormat
* @return
*/
public static String formatSource2Target(String dateStr, String sourceFormat, String targetFormat) {
Date date = formatStr2Date(dateStr, sourceFormat);
return formatDate2Str(date, targetFormat);
}
/**
* 計算當天是該年中的第幾周
* @return
*/
public static int findWeeksNoInYear() {
return findWeeksNoInYear(new Date());
}
/**
* 計算指定日期是該年中的第幾周
* @param date
* @return
*/
public static int findWeeksNoInYear(Date date) {
if (date == null) {
return 0;
}
return findWeeksNoInYear(date2Calendar(date));
}
/**
* 計算指定日曆是該年中的第幾周
* @param calendar
* @return
*/
public static int findWeeksNoInYear(Calendar calendar) {
if (calendar == null) {
return 0;
}
return calendar.get(Calendar.WEEK_OF_YEAR);
}
/**
* 計算一年中的第幾星期是幾號
* @param year
* @param weekInYear
* @param dayInWeek
* @return
*/
public static Date findDateInWeekOnYear(int year, int weekInYear, int dayInWeek) {
Calendar calendar = Calendar.getInstance();
if (year > 0) {
calendar.set(Calendar.YEAR, year);
}
calendar.set(Calendar.WEEK_OF_YEAR, weekInYear);
calendar.set(Calendar.DAY_OF_WEEK, dayInWeek);
return calendar.getTime();
}
/**
* 相對於當前日期的前幾天(days < 0０００００)或者後幾天(days > 0)
* @param days
* @return
*/
public static Date dayBefore2Date(int days) {
Date date = new Date();
return dayBefore2Object(days, null, date);
}
/**
* 相對於當前日期的前幾天(days < 0０００００)或者後幾天(days > 0)
* @param days
* @return
*/
public static String dayBefore2Str(int days) {
String string = formatDate2Str();
return dayBefore2Object(days, null, string);
}
/**
* 相對於當前日期的前幾天(days < 0０００００)或者後幾天(days > 0)
* @param days
* @param format
* @param instance
*/
@SuppressWarnings("unchecked")
public static <T extends Object> T dayBefore2Object(int days, String format, T instance) {
Calendar calendar = Calendar.getInstance();
if (days == 0) {
return null;
}
if (format == null || format.equals("")) {
format = C_TIME_PATTON_DEFAULT;
}
calendar.add(Calendar.DATE, days);
if (instance instanceof Date) {
return (T)calendar.getTime();
} else if (instance instanceof String) {
return (T)formatDate2Str(calendar2Date(calendar), format);
}
return null;
}
/**
* 相對於指定日期的前幾天(days < 0０００００)或者後幾天(days > 0)
* @param date
* @param days
* @return
*/
public static Date defineDayBefore2Date(Date date, int days) {
Date dateInstance = new Date();
return defineDayBefore2Object(date, days, null, dateInstance);
}
/**
* 相對於指定日期的前幾天(days < 0０００００)或者後幾天(days > 0)
* @param date
* @param days
* @return
*/
public static String defineDayBefore2Str(Date date, int days) {
String stringInstance = formatDate2Str();
return defineDayBefore2Object(date, days, null, stringInstance);
}
/**
* 相對於指定日期的前幾天(days < 0０００００)或者後幾天(days > 0)
* @param <T>
* @param date
* @param days
* @param format
* @param instance
* @return
*/
@SuppressWarnings("unchecked")
public static <T extends Object> T defineDayBefore2Object(Date date,
int days, String format, T instance) {
if (date == null || days == 0) {
return null;
}
if (format == null || format.equals("")) {
format = C_TIME_PATTON_DEFAULT;
}
Calendar calendar = date2Calendar(date);
calendar.add(Calendar.DATE, days);
if (instance instanceof Date) {
return (T)calendar.getTime();
} else if (instance instanceof String) {
return (T)formatDate2Str(calendar2Date(calendar), format);
}
return null;
}
/**
* 相對於當前日期的前幾月(months < 0０００００)或者後幾月(months > 0)時間
* @param months
* @return
*/
public static Date monthBefore2Date(int months) {
Date date = new Date();
return monthBefore2Object(months, null, date);
}
/**
* 相對於當前日期的前幾月(months < 0０００００)或者後幾月(months > 0)時間
* @param months
* @return
*/
public static String monthBefore2Str(int months) {
String string = formatDate2Str();
return monthBefore2Object(months, null, string);
}
/**
* 相對於當前日期的前幾月(months < 0０００００)或者後幾月(months > 0)時間
* @param <T>
* @param months
* @param format
* @param instance
*/
@SuppressWarnings("unchecked")
public static <T extends Object> T monthBefore2Object(int months, String format, T instance) {
if (months == 0) {
return null;
}
if (format == null || format.equals("")) {
format = C_TIME_PATTON_DEFAULT;
}
Calendar calendar = Calendar.getInstance();
calendar.add(Calendar.MONTH, months);
if (instance instanceof Date) {
return (T)calendar.getTime();
} else if (instance instanceof String) {
return (T)formatDate2Str(calendar2Date(calendar), format);
}
return null;
}
/**
* 相對於指定日期的前幾月(months < 0０００００)或者後幾月(months > 0)時間
* @param date
* @param months
* @return
*/
public static Date defineMonthBefore2Date(Date date, int months) {
Date dateInstance = new Date();
return defineMonthBefore2Object(date, months, null, dateInstance);
}
/**
* 相對於指定日期的前幾月(months < 0０００００)或者後幾月(months > 0)時間
* @param date
* @param months
* @return
*/
public static String defineMonthBefore2Str(Date date, int months) {
String stringInstance = formatDate2Str();
return defineMonthBefore2Object(date, months, null, stringInstance);
}
/**
* 相對於指定日期的前幾月(months < 0０００００)或者後幾月(months > 0)時間
* @param <T>
* @param date
* @param months
* @param format
* @param instance
* @return
*/
@SuppressWarnings("unchecked")
public static <T extends Object> T defineMonthBefore2Object(Date date,
int months, String format, T instance) {
if (months == 0) {
return null;
}
if (format == null || format.equals("")) {
format = C_TIME_PATTON_DEFAULT;
}
Calendar calendar = date2Calendar(date);
calendar.add(Calendar.MONTH, months);
if (instance instanceof Date) {
return (T)calendar.getTime();
} else if (instance instanceof String) {
return (T)formatDate2Str(calendar2Date(calendar), format);
}
return null;
}
/**
* 計算兩個日期直接差的天數
* @param firstDate
* @param secondDate
* @return
*/
public static int caculate2Days(Date firstDate, Date secondDate) {
Calendar calendar = Calendar.getInstance();
calendar.setTime(firstDate);
int dayNum1 = calendar.get(Calendar.DAY_OF_YEAR);
calendar.setTime(secondDate);
int dayNum2 = calendar.get(Calendar.DAY_OF_YEAR);
return Math.abs(dayNum1 - dayNum2);
}
/**
* 計算兩個日期直接差的天數
* @param firstCalendar
* @param secondCalendar
* @return
*/
public static int caculate2Days(Calendar firstCalendar, Calendar secondCalendar) {
if (firstCalendar.after(secondCalendar)) {
Calendar calendar = firstCalendar;
firstCalendar = secondCalendar;
secondCalendar = calendar;
}
long calendarNum1 = firstCalendar.getTimeInMillis();
long calendarNum2 = secondCalendar.getTimeInMillis();
return Math.abs((int)((calendarNum1 - calendarNum2)/C_ONE_DAY));
}
public static void main(String[] args) {
// System.out.println("當前月份的最大天數:" + findMaxDayInMonth(new Date()));
// System.out.println("6月份的最大天數:" + findMaxDayInMonth(6));
// System.out.println("1999-02月份的最大天數:" + findMaxDayInMonth(1999, 2));
// System.out.println("2000-02月份的最大天數:" + findMaxDayInMonth(2000, 2));
// System.out.println(formatSource2Target("2009-07-24 11:02:35", null, "yyyy/MM/dd"));
// System.out.println(findWeeksNoInYear());
// System.out.println("2003年的第30個星期一是那天:" + findDateInWeekOnYear(2003, 30, Calendar.MONDAY));
// System.out.println("2009年的第30個星期一是那天:" + findDateInWeekOnYear(2009, 30, Calendar.FRIDAY));
// System.out.println("【日期格式】當前日期的前7天是:" + dayBefore2Date(-7));
// System.out.println("【字元格式】當前日期的前7天是:" + dayBefore2Str(-7));
// System.out.println("【日期格式】當前日期的後7天是:" + dayBefore2Date(7));
// System.out.println("【字元格式】當前日期的後7天是:" + dayBefore2Str(7));
// System.out.println(formatStr2Date("2009-07-22", "yyyy-MM-dd"));
// System.out.println("【日期格式】2009-07-22的前7天是:" +
// defineDayBefore2Date(formatStr2Date("2009-07-22", "yyyy-MM-dd"), -7));
// System.out.println("【字元格式】2009-07-22的前7天是:" +
// defineDayBefore2Str(formatStr2Date("2009-07-22", "yyyy-MM-dd"), -7));
// System.out.println("【日期格式】2009-07-22的後7天是:" +
// defineDayBefore2Date(formatStr2Date("2009-07-22", "yyyy-MM-dd"), 7));
// System.out.println("【字元格式】2009-07-22的後7天是:" +
// defineDayBefore2Str(formatStr2Date("2009-07-22", "yyyy-MM-dd"), 7));
// System.out.println("【日期格式】相對於當前時間的前2月日期是:" + monthBefore2Date(-2));
// System.out.println("【字元格式】相對於當前時間的前2月日期是:" + monthBefore2Date(-2));
// System.out.println("【日期格式】相對於當前時間的後2月日期是:" + monthBefore2Date(2));
// System.out.println("【字元格式】相對於當前時間的後2月日期是:" + monthBefore2Date(2));
// System.out.println("【日期格式】2009-07-22的前2月日期是:" +
// defineMonthBefore2Date(formatStr2Date("2009-07-22", "yyyy-MM-dd"), -2));
// System.out.println("【字元格式】2009-07-22的前2月日期是:" +
// defineMonthBefore2Date(formatStr2Date("2009-07-22", "yyyy-MM-dd"), -2));
// System.out.println("【日期格式】2009-07-22的後2月日期是:" +
// defineMonthBefore2Date(formatStr2Date("2009-07-22", "yyyy-MM-dd"), 2));
// System.out.println("【字元格式】2009-07-22的後2月日期是:" +
// defineMonthBefore2Date(formatStr2Date("2009-07-22", "yyyy-MM-dd"), 2));
// Date firstDate = formatStr2Date("2009-07-22", "yyyy-MM-dd");
// Date secondDate = formatStr2Date("2009-07-18", "yyyy-MM-dd");
// System.out.println(caculate2Days(firstDate, secondDate));
Calendar firstC = date2Calendar(formatStr2Date("2009-07-22", "yyyy-MM-dd"));
Calendar secondC = date2Calendar(formatStr2Date("2009-07-18", "yyyy-MM-dd"));
System.out.println(caculate2Days(firstC, secondC));
}
}