记录几个和时间有关的方法

/**
* 获取当前7天。
* @param format
* @return String format格式的日期字符串。
*/
public static String[] getDateArray(String format) {
String[] dateArray = new String[7];
Calendar rightNow = Calendar.getInstance();
SimpleDateFormat sim = new SimpleDateFormat(format);
// 得到当前时间，+N天

rightNow.add(Calendar.DAY_OF_MONTH, -1);
for (int i = 0; i < 7; i++) {

rightNow.add(Calendar.DAY_OF_MONTH, 1);
dateArray[i] = sim.format(rightNow.getTime());
}
return dateArray;

}

/**
* 1:年,2:月,3:日,4:星期
*
* @param time
* @param type
* @return
*/
public static String getDateFromStr(String time, int type) {
String result = "";
try {
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");

Date date = sdf.parse(time);
Calendar cale = Calendar.getInstance();
cale.setTime(date);
switch (type) {
case 1:
int year = cale.get(Calendar.YEAR);
result = String.valueOf(year);
break;
case 2:
int month = (cale.get(Calendar.MONTH)) + 1;
result = String.valueOf(month);
break;
case 3:
int day = cale.get(Calendar.DAY_OF_MONTH);
result = String.valueOf(day);
break;
case 4:
int week = cale.get(Calendar.DAY_OF_WEEK) - 1;
switch (week) {
case 1:

result = "星期一";
break;
case 2:

result = "星期二";
break;
case 3:

result = "星期三";
break;
case 4:

result = "星期四";
break;
case 5:

result = "星期五";
break;
case 6:

result = "星期六";
break;
case 0:

result = "星期日";
break;

default:
break;
}
break;

default:
break;
}
} catch (Exception e) {
return "";
}
return result;
}

/**
* 获取某月的 天数
* @param month
* @return int 天数
*/
public int getCurrentMonthDay(int month) {
Calendar a = Calendar.getInstance();
a.set(Calendar.MONTH, month - 1);//获取当月就把这两行注释掉
a.add(Calendar.MONTH, -1);
a.set(Calendar.DATE, 1);
a.roll(Calendar.DATE, -1);
int maxDate = a.get(Calendar.DATE);
return maxDate;
}

/**
* 指定某年中的某月的第一天是星期几
* @param year
* @param month
* @return int 星期几 0:周日
*/
public int getWeekdayOfMonth(int year, int month) {
Calendar cal = Calendar.getInstance();
cal.set(year, month - 1, 1);
return cal.get(Calendar.DAY_OF_WEEK) - 1;
}

/*
* Copyright (C) 2012 www.amsoft.cn
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*     http://www.apache.org/licenses/LICENSE-2.0 *
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.ab.util;

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;

// TODO: Auto-generated Javadoc

/**
* © 2012 amsoft.cn
* 名称：AbDateUtil.java
* 描述：日期处理类.
*
* @author 还如一梦中
* @version v1.0
* @date：2013-01-18 下午11:52:13
*/
public class AbDateUtil {

/**
* 时间日期格式化到年月日时分秒.
*/
public static final String dateFormatYMDHMS = "yyyy-MM-dd HH:mm:ss";

/**
* 时间日期格式化到年月日.
*/
public static final String dateFormatYMD = "yyyy-MM-dd";

/**
* 时间日期格式化到年月.
*/
public static final String dateFormatYM = "yyyy-MM";

/**
* 时间日期格式化到年月日时分.
*/
public static final String dateFormatYMDHM = "yyyy-MM-dd HH:mm";

/**
* 时间日期格式化到月日.
*/
public static final String dateFormatMD = "MM/dd";

/**
* 时分秒.
*/
public static final String dateFormatHMS = "HH:mm:ss";

/**
* 时分.
*/
public static final String dateFormatHM = "HH:mm";

/**
* 上午.
*/
public static final String AM = "AM";

/**
* 下午.
*/
public static final String PM = "PM";

/**
* 描述：String类型的日期时间转化为Date类型.
*
* @param strDate String形式的日期时间
* @param format  格式化字符串，如："yyyy-MM-dd HH:mm:ss"
* @return Date Date类型日期时间
*/
public static Date getDateByFormat(String strDate, String format) {
SimpleDateFormat mSimpleDateFormat = new SimpleDateFormat(format);
Date date = null;
try {
date = mSimpleDateFormat.parse(strDate);
} catch (ParseException e) {
e.printStackTrace();
}
return date;
}

/**
* 描述：获取偏移之后的Date.
*
* @param date          日期时间
* @param calendarField Calendar属性，对应offset的值， 如(Calendar.DATE,表示+offset天,Calendar.HOUR_OF_DAY,表示＋offset小时)
* @param offset        偏移(值大于0,表示+,值小于0,表示－)
* @return Date 偏移之后的日期时间
*/
public Date getDateByOffset(Date date, int calendarField, int offset) {
Calendar c = new GregorianCalendar();
try {
c.setTime(date);
c.add(calendarField, offset);
} catch (Exception e) {
e.printStackTrace();
}
return c.getTime();
}

/**
* 描述：获取指定日期时间的字符串(可偏移).
*
* @param strDate       String形式的日期时间
* @param format        格式化字符串，如："yyyy-MM-dd HH:mm:ss"
* @param calendarField Calendar属性，对应offset的值， 如(Calendar.DATE,表示+offset天,Calendar.HOUR_OF_DAY,表示＋offset小时)
* @param offset        偏移(值大于0,表示+,值小于0,表示－)
* @return String String类型的日期时间
*/
public static String getStringByOffset(String strDate, String format, int calendarField, int offset) {
String mDateTime = null;
try {
Calendar c = new GregorianCalendar();
SimpleDateFormat mSimpleDateFormat = new SimpleDateFormat(format);
c.setTime(mSimpleDateFormat.parse(strDate));
c.add(calendarField, offset);
mDateTime = mSimpleDateFormat.format(c.getTime());
} catch (ParseException e) {
e.printStackTrace();
mDateTime = "";
}
return mDateTime;
}

/**
* 描述：Date类型转化为String类型(可偏移).
*
* @param date          the date
* @param format        the format
* @param calendarField the calendar field
* @param offset        the offset
* @return String String类型日期时间
*/
public static String getStringByOffset(Date date, String format, int calendarField, int offset) {
String strDate = null;
try {
Calendar c = new GregorianCalendar();
SimpleDateFormat mSimpleDateFormat = new SimpleDateFormat(format);
c.setTime(date);
c.add(calendarField, offset);
strDate = mSimpleDateFormat.format(c.getTime());
} catch (Exception e) {
e.printStackTrace();
strDate = "";
}
return strDate;
}

/**
* 描述：Date类型转化为String类型.
*
* @param date   the date
* @param format the format
* @return String String类型日期时间
*/
public static String getStringByFormat(Date date, String format) {
SimpleDateFormat mSimpleDateFormat = new SimpleDateFormat(format);
String strDate = null;
try {
strDate = mSimpleDateFormat.format(date);
} catch (Exception e) {
e.printStackTrace();
strDate = "";
}
return strDate;
}

/**
* 描述：获取指定日期时间的字符串,用于导出想要的格式.
*
* @param strDate String形式的日期时间，必须为yyyy-MM-dd HH:mm:ss格式
* @param format  输出格式化字符串，如："yyyy-MM-dd HH:mm:ss"
* @return String 转换后的String类型的日期时间
*/
public static String getStringByFormat(String strDate, String format) {
String mDateTime;
try {
Calendar c = new GregorianCalendar();
SimpleDateFormat mSimpleDateFormat = new SimpleDateFormat(dateFormatYMDHMS);
c.setTime(mSimpleDateFormat.parse(strDate));
SimpleDateFormat mSimpleDateFormat2 = new SimpleDateFormat(format);
mDateTime = mSimpleDateFormat2.format(c.getTime());
} catch (Exception e) {
e.printStackTrace();
mDateTime = "";
}
return mDateTime;
}

/**
* 描述：获取milliseconds表示的日期时间的字符串.
*
* @param milliseconds the milliseconds
* @param format       格式化字符串，如："yyyy-MM-dd HH:mm:ss"
* @return String 日期时间字符串
*/
public static String getStringByFormat(long milliseconds, String format) {
String thisDateTime;
try {
SimpleDateFormat mSimpleDateFormat = new SimpleDateFormat(format);
thisDateTime = mSimpleDateFormat.format(milliseconds);
} catch (Exception e) {
e.printStackTrace();
thisDateTime = "";
}
return thisDateTime;
}

/**
* 描述：获取milliseconds表示的日期时间的字符串.
*
* @param longTimeStamp 时间戳(秒)
* @param format       格式化字符串，如："yyyy-MM-dd HH:mm:ss"
* @return String 日期时间字符串
*/
public static String getString2StringByFormat(String longTimeStamp, String format) {
String thisDateTime;
try {

SimpleDateFormat mSimpleDateFormat = new SimpleDateFormat(format);
thisDateTime = mSimpleDateFormat.format(Long.parseLong(longTimeStamp) * 1000);
} catch (Exception e) {
e.printStackTrace();
thisDateTime = "";
}
return thisDateTime;
}

/**
* 描述：获取表示当前日期时间的字符串.
*
* @param format 格式化字符串，如："yyyy-MM-dd HH:mm:ss"
* @return String String类型的当前日期时间
*/
public static String getCurrentDate(String format) {
AbLogUtil.d(AbDateUtil.class, "getCurrentDate:" + format);
String curDateTime;
try {
SimpleDateFormat mSimpleDateFormat = new SimpleDateFormat(format);
Calendar c = new GregorianCalendar();
curDateTime = mSimpleDateFormat.format(c.getTime());
} catch (Exception e) {
e.printStackTrace();
curDateTime = "";
}
return curDateTime;

}

/**
* 描述：获取表示当前日期时间的字符串(可偏移).
*
* @param format        格式化字符串，如："yyyy-MM-dd HH:mm:ss"
* @param calendarField Calendar属性，对应offset的值， 如(Calendar.DATE,表示+offset天,Calendar.HOUR_OF_DAY,表示＋offset小时)
* @param offset        偏移(值大于0,表示+,值小于0,表示－)
* @return String String类型的日期时间
*/
public static String getCurrentDateByOffset(String format, int calendarField, int offset) {
String mDateTime;
try {
SimpleDateFormat mSimpleDateFormat = new SimpleDateFormat(format);
Calendar c = new GregorianCalendar();
c.add(calendarField, offset);
mDateTime = mSimpleDateFormat.format(c.getTime());
} catch (Exception e) {
e.printStackTrace();
mDateTime = "";
}
return mDateTime;

}

/**
* 描述：计算两个日期所差的天数.
*
* @param milliseconds1 the milliseconds1
* @param milliseconds2 the milliseconds2
* @return int 所差的天数
*/
public static int getOffectDay(long milliseconds1, long milliseconds2) {
Calendar calendar1 = Calendar.getInstance();
calendar1.setTimeInMillis(milliseconds1);
Calendar calendar2 = Calendar.getInstance();
calendar2.setTimeInMillis(milliseconds2);
//先判断是否同年
int y1 = calendar1.get(Calendar.YEAR);
int y2 = calendar2.get(Calendar.YEAR);
int d1 = calendar1.get(Calendar.DAY_OF_YEAR);
int d2 = calendar2.get(Calendar.DAY_OF_YEAR);
int maxDays = 0;
int day = 0;
if (y1 - y2 > 0) {
maxDays = calendar2.getActualMaximum(Calendar.DAY_OF_YEAR);
day = d1 - d2 + maxDays;
} else if (y1 - y2 < 0) {
maxDays = calendar1.getActualMaximum(Calendar.DAY_OF_YEAR);
day = d1 - d2 - maxDays;
} else {
day = d1 - d2;
}
return day;
}

/**
* 描述：计算两个日期所差的小时数.
*
* @param date1 第一个时间的毫秒表示
* @param date2 第二个时间的毫秒表示
* @return int 所差的小时数
*/
public static int getOffectHour(long date1, long date2) {
Calendar calendar1 = Calendar.getInstance();
calendar1.setTimeInMillis(date1);
Calendar calendar2 = Calendar.getInstance();
calendar2.setTimeInMillis(date2);
int h1 = calendar1.get(Calendar.HOUR_OF_DAY);
int h2 = calendar2.get(Calendar.HOUR_OF_DAY);
int h = 0;
int day = getOffectDay(date1, date2);
h = h1 - h2 + day * 24;
return h;
}

/**
* 描述：计算两个日期所差的分钟数.
*
* @param date1 第一个时间的毫秒表示
* @param date2 第二个时间的毫秒表示
* @return int 所差的分钟数
*/
public static int getOffectMinutes(long date1, long date2) {
Calendar calendar1 = Calendar.getInstance();
calendar1.setTimeInMillis(date1);
Calendar calendar2 = Calendar.getInstance();
calendar2.setTimeInMillis(date2);
int m1 = calendar1.get(Calendar.MINUTE);
int m2 = calendar2.get(Calendar.MINUTE);
int h = getOffectHour(date1, date2);
int m = 0;
m = m1 - m2 + h * 60;
return m;
}

/**
* 描述：获取本周一.
*
* @param format the format
* @return String String类型日期时间
*/
public static String getFirstDayOfWeek(String format) {
return getDayOfWeek(format, Calendar.MONDAY);
}

/**
* 描述：获取本周日.
*
* @param format the format
* @return String String类型日期时间
*/
public static String getLastDayOfWeek(String format) {
return getDayOfWeek(format, Calendar.SUNDAY);
}

/**
* 描述：获取本周的某一天.
*
* @param format        the format
* @param calendarField the calendar field
* @return String String类型日期时间
*/
private static String getDayOfWeek(String format, int calendarField) {
String strDate = null;
try {
Calendar c = new GregorianCalendar();
SimpleDateFormat mSimpleDateFormat = new SimpleDateFormat(format);
int week = c.get(Calendar.DAY_OF_WEEK);
if (week == calendarField) {
strDate = mSimpleDateFormat.format(c.getTime());
} else {
int offectDay = calendarField - week;
if (calendarField == Calendar.SUNDAY) {
offectDay = 7 - Math.abs(offectDay);
}
c.add(Calendar.DATE, offectDay);
strDate = mSimpleDateFormat.format(c.getTime());
}
} catch (Exception e) {
e.printStackTrace();
strDate = "";
}
return strDate;
}

/**
* 描述：获取本月第一天.
*
* @param format the format
* @return String String类型日期时间
*/
public static String getFirstDayOfMonth(String format) {
String strDate = null;
try {
Calendar c = new GregorianCalendar();
SimpleDateFormat mSimpleDateFormat = new SimpleDateFormat(format);
//当前月的第一天
c.set(GregorianCalendar.DAY_OF_MONTH, 1);
strDate = mSimpleDateFormat.format(c.getTime());
} catch (Exception e) {
e.printStackTrace();
strDate = "";
}
return strDate;

}

/**
* 描述：获取本月最后一天.
*
* @param format the format
* @return String String类型日期时间
*/
public static String getLastDayOfMonth(String format) {
String strDate = null;
try {
Calendar c = new GregorianCalendar();
SimpleDateFormat mSimpleDateFormat = new SimpleDateFormat(format);
// 当前月的最后一天
c.set(Calendar.DATE, 1);
c.roll(Calendar.DATE, -1);
strDate = mSimpleDateFormat.format(c.getTime());
} catch (Exception e) {
e.printStackTrace();
strDate = "";
}
return strDate;
}

/**
* 描述：获取表示当前日期的0点时间毫秒数.
*
* @return the first time of day
*/
public static long getFirstTimeOfDay() {
Date date = null;
try {
String currentDate = getCurrentDate(dateFormatYMD);
date = getDateByFormat(currentDate + " 00:00:00", dateFormatYMDHMS);
return date.getTime();
} catch (Exception e) {
}
return -1;
}

/**
* 描述：获取表示当前日期24点时间毫秒数.
*
* @return the last time of day
*/
public static long getLastTimeOfDay() {
Date date = null;
try {
String currentDate = getCurrentDate(dateFormatYMD);
date = getDateByFormat(currentDate + " 24:00:00", dateFormatYMDHMS);
return date.getTime();
} catch (Exception e) {
}
return -1;
}

/**
* 描述：判断是否是闰年()
* <p>(year能被4整除 并且 不能被100整除) 或者 year能被400整除,则该年为闰年.
*
* @param year 年代（如2012）
* @return boolean 是否为闰年
*/
public static boolean isLeapYear(int year) {
if ((year % 4 == 0 && year % 400 != 0) || year % 400 == 0) {
return true;
} else {
return false;
}
}

/**
* 描述：根据时间返回格式化后的时间的描述.
* 小于1小时显示多少分钟前  大于1小时显示今天＋实际日期，大于今天全部显示实际时间
*
* @param strDate   the str date
* @param outFormat the out format
* @return the string
*/
public static String formatDateStr2Desc(String strDate, String outFormat) {

DateFormat df = new SimpleDateFormat(dateFormatYMDHMS);
Calendar c1 = Calendar.getInstance();
Calendar c2 = Calendar.getInstance();
try {
c2.setTime(df.parse(strDate));
c1.setTime(new Date());
int d = getOffectDay(c1.getTimeInMillis(), c2.getTimeInMillis());
if (d == 0) {
int h = getOffectHour(c1.getTimeInMillis(), c2.getTimeInMillis());
if (h > 0) {
return "今天" + getStringByFormat(strDate, dateFormatHM);
//return h + "小时前";
} else if (h < 0) {
//return Math.abs(h) + "小时后";
} else if (h == 0) {
int m = getOffectMinutes(c1.getTimeInMillis(), c2.getTimeInMillis());
if (m > 0) {
return m + "分钟前";
} else if (m < 0) {
//return Math.abs(m) + "分钟后";
} else {
return "刚刚";
}
}

} else if (d > 0) {
if (d == 1) {
//return "昨天"+getStringByFormat(strDate,outFormat);
} else if (d == 2) {
//return "前天"+getStringByFormat(strDate,outFormat);
}
} else if (d < 0) {
if (d == -1) {
//return "明天"+getStringByFormat(strDate,outFormat);
} else if (d == -2) {
//return "后天"+getStringByFormat(strDate,outFormat);
} else {
//return Math.abs(d) + "天后"+getStringByFormat(strDate,outFormat);
}
}

String out = getStringByFormat(strDate, outFormat);
if (!AbStrUtil.isEmpty(out)) {
return out;
}
} catch (Exception e) {
}

return strDate;
}

/**
* 取指定日期为星期几.
*
* @param strDate  指定日期
* @param inFormat 指定日期格式
* @return String   星期几
*/
public static String getWeekNumber(String strDate, String inFormat) {
String week = "星期日";
Calendar calendar = new GregorianCalendar();
DateFormat df = new SimpleDateFormat(inFormat);
try {
calendar.setTime(df.parse(strDate));
} catch (Exception e) {
return "错误";
}
int intTemp = calendar.get(Calendar.DAY_OF_WEEK) - 1;
switch (intTemp) {
case 0:
week = "星期日";
break;
case 1:
week = "星期一";
break;
case 2:
week = "星期二";
break;
case 3:
week = "星期三";
break;
case 4:
week = "星期四";
break;
case 5:
week = "星期五";
break;
case 6:
week = "星期六";
break;
}
return week;
}

/**
* 根据给定的日期判断是否为上下午.
*
* @param strDate the str date
* @param format  the format
* @return the time quantum
*/
public static String getTimeQuantum(String strDate, String format) {
Date mDate = getDateByFormat(strDate, format);
int hour = mDate.getHours();
if (hour >= 12)
return "PM";
else
return "AM";
}

/**
* 根据给定的毫秒数算得时间的描述.
*
* @param milliseconds the milliseconds
* @return the time description
*/
public static String getTimeDescription(long milliseconds) {
if (milliseconds > 1000) {
//大于一分
if (milliseconds / 1000 / 60 > 1) {
long minute = milliseconds / 1000 / 60;
long second = milliseconds / 1000 % 60;
return minute + "分" + second + "秒";
} else {
//显示秒
return milliseconds / 1000 + "秒";
}
} else {
return milliseconds + "毫秒";
}
}

/**
* The main method.
*
* @param args the arguments
*/
public static void main(String[] args) {
System.out.println(formatDateStr2Desc("2012-3-2 12:2:20", "MM月dd日  HH:mm"));
}

}