java的时间工具类，包括找各种时间，根据固定格式返回时间

import org.apache.commons.lang3.time.DateFormatUtils;

import java.sql.Timestamp;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.List;

/*
\ @author: Charlie */ public class DateUtils {

public static final String DAYTYPE = "yyyy-MM-dd";

public static final String DAYTIMETYPE = "yyyy-MM-dd HH:mm";

public static final String TIMETYPE = "yyyy-MM-dd HH:mm:ss";

public static final String DATETYPE = "yyyy年MM月dd日";

public static final String DateTypeYear = "yyyy";

public static final String DateTypeMonth = "yyyyMM";

public static final String Date4ExportType = "yyyyMMdd";

public static final String DateDetail4ExportType = "yyyyMMddHHmmss";

//配合上面的类型传入format参数，返回想要的时间格式

public static String formatDate(Date date, String format) {
if (null == date) {
return null;
}
return DateFormatUtils.format(date, format);
}

//获取当天的开始时间

public static Date getDayBegin() {
Calendar cal = new GregorianCalendar();
cal.set(Calendar.HOUR_OF_DAY, 0);
cal.set(Calendar.MINUTE, 0);
cal.set(Calendar.SECOND, 0);
cal.set(Calendar.MILLISECOND, 0);
return cal.getTime();
}

//获取当天的结束时间

public static Date getDayEnd() {
Calendar cal = new GregorianCalendar();
cal.set(Calendar.HOUR_OF_DAY, 23);
cal.set(Calendar.MINUTE, 59);
cal.set(Calendar.SECOND, 59);
cal.set(Calendar.MILLISECOND, 999);
return cal.getTime();
}

//获取昨天的开始时间

public static Date getBeginDayOfYesterday() {
Calendar cal = new GregorianCalendar();
cal.setTime(getDayBegin());
cal.add(Calendar.DAY_OF_MONTH, -1);
return cal.getTime();
}

//获取昨天的结束时间

public static Date getEndDayOfYesterDay() {
Calendar cal = new GregorianCalendar();
cal.setTime(getDayEnd());
cal.add(Calendar.DAY_OF_MONTH, -1);
return cal.getTime();
}

//获取明天的开始时间

public static Date getBeginDayOfTomorrow() {
Calendar cal = new GregorianCalendar();
cal.setTime(getDayBegin());
cal.add(Calendar.DAY_OF_MONTH, 1);
return cal.getTime();
}

//获取明天的结束时间

public static Date getEndDayOfTomorrow() {
Calendar cal = new GregorianCalendar();
cal.setTime(getDayEnd());
cal.add(Calendar.DAY_OF_MONTH, 1);
return cal.getTime();
}

//获取本周的开始时间

public static Date getBeginDayOfWeek() {
Date date = new Date();
if (date == null) {
return null;
}
Calendar cal = Calendar.getInstance();
cal.setTime(date);
int dayofweek = cal.get(Calendar.DAY_OF_WEEK);
if (dayofweek == 1) {
dayofweek += 7;
}
cal.add(Calendar.DATE, 2 - dayofweek);
return getDayStartTime(cal.getTime());
}

//获取本周的结束时间

public static Date getEndDayOfWeek(){
Calendar cal = Calendar.getInstance();
cal.setTime(getBeginDayOfWeek());
cal.add(Calendar.DAY_OF_WEEK, 6);
Date weekEndSta = cal.getTime();
return getDayEndTime(weekEndSta);
}

//获取本月的开始时间

public static Date getBeginDayOfMonth() {
Calendar calendar = Calendar.getInstance();
calendar.set(getNowYear(), getNowMonth() - 1, 1);
return getDayStartTime(calendar.getTime());
}

//获取本月的结束时间

public static Date getEndDayOfMonth() {
Calendar calendar = Calendar.getInstance();
calendar.set(getNowYear(), getNowMonth() - 1, 1);
int day = calendar.getActualMaximum(5);
calendar.set(getNowYear(), getNowMonth() - 1, day);
return getDayEndTime(calendar.getTime());
}

//获取本年的开始时间

public static Date getBeginDayOfYear() {
Calendar cal = Calendar.getInstance();
cal.set(Calendar.YEAR, getNowYear());
cal.set(Calendar.MONTH, Calendar.JANUARY);
cal.set(Calendar.DATE, 1);
return getDayStartTime(cal.getTime());
}

//获取本年的结束时间

public static Date getEndDayOfYear() {
Calendar cal = Calendar.getInstance();
cal.set(Calendar.YEAR, getNowYear());
cal.set(Calendar.MONTH, Calendar.DECEMBER);
cal.set(Calendar.DATE, 31);
return getDayEndTime(cal.getTime());
}

//获取某个日期的开始时间

public static Timestamp getDayStartTime(Date d) {
Calendar calendar = Calendar.getInstance();
if(null != d){
calendar.setTime(d);
}
calendar.set(calendar.get(Calendar.YEAR), calendar.get(Calendar.MONTH), calendar.get(Calendar.DAY_OF_MONTH), 0, 0, 0);
calendar.set(Calendar.MILLISECOND, 0);
return new Timestamp(calendar.getTimeInMillis());
}

//获取某个日期的结束时间

public static Timestamp getDayEndTime(Date d) {
Calendar calendar = Calendar.getInstance();
if(null != d) {
calendar.setTime(d);
}
calendar.set(calendar.get(Calendar.YEAR), calendar.get(Calendar.MONTH), calendar.get(Calendar.DAY_OF_MONTH), 23, 59, 59);
calendar.set(Calendar.MILLISECOND, 999);
return new Timestamp(calendar.getTimeInMillis());
}

//获取今年是哪一年

public static Integer getNowYear() {
Date date = new Date();
GregorianCalendar gc = (GregorianCalendar) Calendar.getInstance();
gc.setTime(date);
return Integer.valueOf(gc.get(1));
}

//获取本月是哪一月

public static int getNowMonth() {
Date date = new Date();
GregorianCalendar gc = (GregorianCalendar) Calendar.getInstance();
gc.setTime(date);
return gc.get(2) + 1;
}

//两个日期相减得到的天数

public static int getDiffDays(Date beginDate, Date endDate) {
if (beginDate == null || endDate == null) {
throw new IllegalArgumentException(“getDiffDays param is null!”);
}
long diff = (endDate.getTime() - beginDate.getTime())/ (1000 * 60 * 60 * 24);
int days = new Long(diff).intValue();
return days;
}

//两个日期相减得到的毫秒数

public static long dateDiff(Date beginDate, Date endDate) {
long date1ms = beginDate.getTime();
long date2ms = endDate.getTime();
return date2ms - date1ms;
}

//获取两个日期中的最大日期

public static Date max(Date beginDate, Date endDate) {
if (beginDate == null) {
return endDate;
}
if (endDate == null) {
return beginDate;
}
if (beginDate.after(endDate)) {
return beginDate;
}
return endDate;
}

//获取两个日期中的最小日期

public static Date min(Date beginDate, Date endDate) {
if (beginDate == null) {
return endDate;
}
if (endDate == null) {
return beginDate;
}
if (beginDate.after(endDate)) {
return endDate;
}
return beginDate;
}

//返回某月该季度的第一个月

public static Date getFirstSeasonDate(Date date) {
final int[] SEASON = { 1, 1, 1, 2, 2, 2, 3, 3, 3, 4, 4, 4 };
Calendar cal = Calendar.getInstance();
cal.setTime(date);
int sean = SEASON[cal.get(Calendar.MONTH)];
cal.set(Calendar.MONTH, sean * 3 - 3);
return cal.getTime();
}

//返回某个日期下几天的日期

public static Date getNextDay(Date date, int i) {
Calendar cal = new GregorianCalendar();
cal.setTime(date);
cal.set(Calendar.DATE, cal.get(Calendar.DATE) + i);
return cal.getTime();
}

//返回某个日期前几天的日期

public static Date getFrontDay(Date date, int i) {
Calendar cal = new GregorianCalendar();
cal.setTime(date);
cal.set(Calendar.DATE, cal.get(Calendar.DATE) - i);
return cal.getTime();
}

//获取某年某月到某年某月按天的切片日期集合（间隔天数的日期集合）

public static List getTimeList(int beginYear, int beginMonth, int endYear,int endMonth, int k) {
List list = new ArrayList();
if (beginYear == endYear) {
for (int j = beginMonth; j <= endMonth; j++) {
list.add(getTimeList(beginYear, j, k));
}
} else {
for (int j = beginMonth; j < 12; j++) {
list.add(getTimeList(beginYear, j, k));
}
for (int i = beginYear + 1; i < endYear; i++) {
for (int j = 0; j < 12; j++) {
list.add(getTimeList(i, j, k));
}
}
for (int j = 0; j <= endMonth; j++) {
list.add(getTimeList(endYear, j, k));
}
}
return list;
}

//获取某年某月按天切片日期集合（某个月间隔多少天的日期集合）

public static List getTimeList(int beginYear, int beginMonth, int k) {
List list = new ArrayList();
Calendar begincal = new GregorianCalendar(beginYear, beginMonth, 1);
int max = begincal.getActualMaximum(Calendar.DATE);
for (int i = 1; i < max; i = i + k) {
list.add(begincal.getTime());
begincal.add(Calendar.DATE, k);
}
begincal = new GregorianCalendar(beginYear, beginMonth, max);
list.add(begincal.getTime());
return list;
}

//获取某年某月的第一天日期

public static Date getStartMonthDate(int year, int month) {
Calendar calendar = Calendar.getInstance();
calendar.set(year, month - 1, 1);
return calendar.getTime();
}

//获取某年某月的最后一天日期

public static Date getEndMonthDate(int year, int month) {
Calendar calendar = Calendar.getInstance();
calendar.set(year, month - 1, 1);
int day = calendar.getActualMaximum(5);
calendar.set(year, month - 1, day);
return calendar.getTime();
}

}