package com.chinagas.common.utils; import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date; public class DateUtils { public static final String DATE_TIME_PATTERN = "yyyy-MM-dd HH:mm:ss";
public static final String MINUTE_PATTERN = "yyyy-MM-dd HH:mm";
public static final String HOUR_PATTERN = "yyyy-MM-dd HH:mm:ss";
public static final String DATE_PATTERN = "yyyy-MM-dd";
public static final String MONTH_PATTERN = "yyyy-MM";
public static final String YEAR_PATTERN = "yyyy";
public static final String MINUTE_ONLY_PATTERN = "mm";
public static final String HOUR_ONLY_PATTERN = "HH"; /**
* 日期相加减天数
* @param date 如果为Null，则为当前时间
* @param days 加减天数
* @param includeTime 是否包括时分秒,true表示包含
* @return
* @throws ParseException
*/
public static Date dateAdd(Date date, int days, boolean includeTime) throws ParseException{
if(date == null){
date = new Date();
}
if(!includeTime){
SimpleDateFormat sdf = new SimpleDateFormat(DateUtils.DATE_PATTERN);
date = sdf.parse(sdf.format(date));
}
Calendar cal = Calendar.getInstance();
cal.setTime(date);
cal.add(Calendar.DATE, days);
return cal.getTime();
} /**
* 时间格式化成字符串
* @param date Date
* @param pattern StrUtils.DATE_TIME_PATTERN || StrUtils.DATE_PATTERN， 如果为空，则为yyyy-MM-dd
* @return
* @throws ParseException
*/
public static String dateFormat(Date date, String pattern) throws ParseException{
if(StrUtils.isBlank(pattern)){
pattern = DateUtils.DATE_PATTERN;
}
SimpleDateFormat sdf = new SimpleDateFormat(pattern);
return sdf.format(date);
} /**
* 字符串解析成时间对象
* @param dateTimeString String
* @param pattern StrUtils.DATE_TIME_PATTERN || StrUtils.DATE_PATTERN，如果为空，则为yyyy-MM-dd
* @return
* @throws ParseException
*/
public static Date dateParse(String dateTimeString, String pattern) throws ParseException{
if(StrUtils.isBlank(pattern)){
pattern = DateUtils.DATE_PATTERN;
}
SimpleDateFormat sdf = new SimpleDateFormat(pattern);
return sdf.parse(dateTimeString);
} /**
* 将日期时间格式成只有日期的字符串（可以直接使用dateFormat，Pattern为Null进行格式化）
* @param dateTime Date
* @return
* @throws ParseException
*/
public static String dateTimeToDateString(Date dateTime) throws ParseException{
String dateTimeString = DateUtils.dateFormat(dateTime, DateUtils.DATE_TIME_PATTERN);
return dateTimeString.substring(0, 10);
} /**
* 当时、分、秒为00:00:00时，将日期时间格式成只有日期的字符串，
* 当时、分、秒不为00:00:00时，直接返回
* @param dateTime Date
* @return
* @throws ParseException
*/
public static String dateTimeToDateStringIfTimeEndZero(Date dateTime) throws ParseException{
String dateTimeString = DateUtils.dateFormat(dateTime, DateUtils.DATE_TIME_PATTERN);
if(dateTimeString.endsWith("00:00:00")){
return dateTimeString.substring(0, 10);
}else{
return dateTimeString;
}
} /**
* 将日期时间格式成日期对象，和dateParse互用
* @param dateTime Date
* @return Date
* @throws ParseException
*/
public static Date dateTimeToDate(Date dateTime) throws ParseException{
Calendar cal = Calendar.getInstance();
cal.setTime(dateTime);
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();
} /**
* 时间加减小时
* @param startDate 要处理的时间，Null则为当前时间
* @param hours 加减的小时
* @return Date
*/
public static Date dateAddHours(Date startDate, int hours) {
if (startDate == null) {
startDate = new Date();
}
Calendar c = Calendar.getInstance();
c.setTime(startDate);
c.set(Calendar.HOUR, c.get(Calendar.HOUR) + hours);
return c.getTime();
} /**
* 时间加减分钟
* @param startDate 要处理的时间，Null则为当前时间
* @param minutes 加减的分钟
* @return
*/
public static Date dateAddMinutes(Date startDate, int minutes) {
if (startDate == null) {
startDate = new Date();
}
Calendar c = Calendar.getInstance();
c.setTime(startDate);
c.set(Calendar.MINUTE, c.get(Calendar.MINUTE) + minutes);
return c.getTime();
} /**
* 时间加减秒数
* @param startDate 要处理的时间，Null则为当前时间
* @param minutes 加减的秒数
* @return
*/
public static Date dateAddSeconds(Date startDate, int seconds) {
if (startDate == null) {
startDate = new Date();
}
Calendar c = Calendar.getInstance();
c.setTime(startDate);
c.set(Calendar.SECOND, c.get(Calendar.SECOND) + seconds);
return c.getTime();
} /**
* 时间加减天数
* @param startDate 要处理的时间，Null则为当前时间
* @param days 加减的天数
* @return Date
*/
public static Date dateAddDays(Date startDate, int days) {
if (startDate == null) {
startDate = new Date();
}
Calendar c = Calendar.getInstance();
c.setTime(startDate);
c.set(Calendar.DATE, c.get(Calendar.DATE) + days);
return c.getTime();
} /**
* 时间加减月数
* @param startDate 要处理的时间，Null则为当前时间
* @param months 加减的月数
* @return Date
*/
public static Date dateAddMonths(Date startDate, int months) {
if (startDate == null) {
startDate = new Date();
}
Calendar c = Calendar.getInstance();
c.setTime(startDate);
c.set(Calendar.MONTH, c.get(Calendar.MONTH) + months);
return c.getTime();
} /**
* 时间加减年数
* @param startDate 要处理的时间，Null则为当前时间
* @param years 加减的年数
* @return Date
*/
public static Date dateAddYears(Date startDate, int years) {
if (startDate == null) {
startDate = new Date();
}
Calendar c = Calendar.getInstance();
c.setTime(startDate);
c.set(Calendar.YEAR, c.get(Calendar.YEAR) + years);
return c.getTime();
} /**
* 时间比较（如果myDate>compareDate返回1，<返回-1，相等返回0）
* @param myDate 时间
* @param compareDate 要比较的时间
* @return int
*/
public static int dateCompare(Date myDate, Date compareDate) {
Calendar myCal = Calendar.getInstance();
Calendar compareCal = Calendar.getInstance();
myCal.setTime(myDate);
compareCal.setTime(compareDate);
return myCal.compareTo(compareCal);
} /**
* 获取两个时间中最小的一个时间
* @param date
* @param compareDate
* @return
*/
public static Date dateMin(Date date, Date compareDate) {
if(date == null){
return compareDate;
}
if(compareDate == null){
return date;
}
if(1 == dateCompare(date, compareDate)){
return compareDate;
}else if(-1 == dateCompare(date, compareDate)){
return date;
}
return date;
} /**
* 获取两个时间中最大的一个时间
* @param date
* @param compareDate
* @return
*/
public static Date dateMax(Date date, Date compareDate) {
if(date == null){
return compareDate;
}
if(compareDate == null){
return date;
}
if(1 == dateCompare(date, compareDate)){
return date;
}else if(-1 == dateCompare(date, compareDate)){
return compareDate;
}
return date;
} /**
* 获取两个日期（不含时分秒）相差的天数，不包含今天
* @param startDate
* @param endDate
* @return
* @throws ParseException
*/
public static int dateBetween(Date startDate, Date endDate) throws ParseException {
Date dateStart = dateParse(dateFormat(startDate, DATE_PATTERN), DATE_PATTERN);
Date dateEnd = dateParse(dateFormat(endDate, DATE_PATTERN), DATE_PATTERN);
return (int) ((dateEnd.getTime() - dateStart.getTime())/1000/60/60/24);
} /**
* 获取两个日期（不含时分秒）相差的天数，包含今天
* @param startDate
* @param endDate
* @return
* @throws ParseException
*/
public static int dateBetweenIncludeToday(Date startDate, Date endDate) throws ParseException {
return dateBetween(startDate, endDate) + 1;
} /**
* 获取日期时间的年份，如2017-02-13，返回2017
* @param date
* @return
*/
public static int getYear(Date date) {
Calendar cal = Calendar.getInstance();
cal.setTime(date);
return cal.get(Calendar.YEAR);
} /**
* 获取日期时间的月份，如2017年2月13日，返回2
* @param date
* @return
*/
public static int getMonth(Date date) {
Calendar cal = Calendar.getInstance();
cal.setTime(date);
return cal.get(Calendar.MONTH) + 1;
} /**
* 获取日期时间的第几天（即返回日期的dd），如2017-02-13，返回13
* @param date
* @return
*/
public static int getDate(Date date) {
Calendar cal = Calendar.getInstance();
cal.setTime(date);
return cal.get(Calendar.DATE);
} /**
* 获取日期时间当月的总天数，如2017-02-13，返回28
* @param date
* @return
*/
public static int getDaysOfMonth(Date date) {
Calendar cal = Calendar.getInstance();
cal.setTime(date);
return cal.getActualMaximum(Calendar.DATE);
} /**
* 获取日期时间当年的总天数，如2017-02-13，返回2017年的总天数
* @param date
* @return
*/
public static int getDaysOfYear(Date date) {
Calendar cal = Calendar.getInstance();
cal.setTime(date);
return cal.getActualMaximum(Calendar.DAY_OF_YEAR);
} /**
* 根据时间获取当月最大的日期
* <li>2017-02-13，返回2017-02-28</li>
* <li>2016-02-13，返回2016-02-29</li>
* <li>2016-01-11，返回2016-01-31</li>
* @param date Date
* @return
* @throws Exception
*/
public static Date maxDateOfMonth(Date date) throws Exception {
Calendar cal = Calendar.getInstance();
cal.setTime(date);
int value = cal.getActualMaximum(Calendar.DATE);
return dateParse(dateFormat(date, MONTH_PATTERN) + "-" + value, null);
} /**
* 根据时间获取当月最小的日期，也就是返回当月的1号日期对象
* @param date Date
* @return
* @throws Exception
*/
public static Date minDateOfMonth(Date date) throws Exception {
Calendar cal = Calendar.getInstance();
cal.setTime(date);
int value = cal.getActualMinimum(Calendar.DATE);
return dateParse(dateFormat(date, MONTH_PATTERN) + "-" + value, null);
} public static void main(String[] args) throws Exception {
/*System.out.println(dateTimeToDate(new Date()));
System.out.println(dateParse("2017-02-04 14:58:20", null));
System.out.println(dateTimeToDateStringIfTimeEndZero(new Date()));
System.out.println(dateTimeToDateStringIfTimeEndZero(dateTimeToDate(new Date())));*/
//System.out.println(dateBetween(dateParse("2017-01-30", null), dateParse("2017-02-01", null)));
//System.out.println(dateBetweenIncludeToday(dateParse("2017-01-30", null), dateParse("2017-02-01", null)));
System.out.println(getDate(dateParse("2017-01-17", null)));
/*
System.out.println(getDaysOfMonth(dateParse("2017-02-01", null)));
System.out.println(getDaysOfYear(dateParse("2017-01-30", null)));*/
//System.out.println(dateFormat(dateAddMonths(dateParse("2017-02-07", StrUtils.MONTH_PATTERN), -12), StrUtils.MONTH_PATTERN));
/*System.out.println(dateFormat(maxDateOfMonth(dateParse("2016-02", "yyyy-MM")), null));
System.out.println(dateFormat(minDateOfMonth(dateParse("2016-03-31", null)), null));*/
} } 原文链接https://www.cnblogs.com/fanshuyao/p/6365099.html