Java工具类DateUtils实例详解
本文实例为大家分享了Java工具类DateUtils的具体代码，供大家参考，具体内容如下
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
/**
* 描述:公共日期工具类
*/
public class DateUtils {
public static String DATE_FORMAT = "yyyy-MM-dd";
public static String DATE_TIME_FORMAT = "yyyy-MM-dd HH:mm:ss";
public static String DATE_FORMAT_CHINESE = "yyyy年M月d日";
/**
* 获取当前日期
*
*
* @return
*
*/
public static String getCurrentDate() {
String datestr = null;
SimpleDateFormat df = new SimpleDateFormat(DateUtils.DATE_FORMAT);
datestr = df.format(new Date());
return datestr;
}
/**
* 获取当前日期时间
*
*
* @return
*
*/
public static String getCurrentDateTime() {
String datestr = null;
SimpleDateFormat df = new SimpleDateFormat(DateUtils.DATE_TIME_FORMAT);
datestr = df.format(new Date());
return datestr;
}
/**
* 获取当前日期时间
*
*
* @return
*
*/
public static String getCurrentDateTime(String Dateformat) {
String datestr = null;
SimpleDateFormat df = new SimpleDateFormat(Dateformat);
datestr = df.format(new Date());
return datestr;
}
public static String dateToDateTime(Date date) {
String datestr = null;
SimpleDateFormat df = new SimpleDateFormat(DateUtils.DATE_TIME_FORMAT);
datestr = df.format(date);
return datestr;
}
/**
* 将字符串日期转换为日期格式
*
*
* @param datestr
* @return
*
*/
public static Date stringToDate(String datestr) {
if(datestr ==null ||datestr.equals("")){
return null;
}
Date date = new Date();
SimpleDateFormat df = new SimpleDateFormat(DateUtils.DATE_FORMAT);
try {
date = df.parse(datestr);
} catch (ParseException e) {
date=DateUtils.stringToDate(datestr,"yyyyMMdd");
}
return date;
}
/**
* 将字符串日期转换为日期格式
* 自定義格式
*
* @param datestr
* @return
*
*/
public static Date stringToDate(String datestr, String dateformat) {
Date date = new Date();
SimpleDateFormat df = new SimpleDateFormat(dateformat);
try {
date = df.parse(datestr);
} catch (ParseException e) {
e.printStackTrace();
}
return date;
}
/**
* 将日期格式日期转换为字符串格式
*
*
* @param date
* @return
*
*/
public static String dateToString(Date date) {
String datestr = null;
SimpleDateFormat df = new SimpleDateFormat(DateUtils.DATE_FORMAT);
datestr = df.format(date);
return datestr;
}
/**
* 将日期格式日期转换为字符串格式 自定義格式
*
* @param date
* @param dateformat
* @return
*/
public static String dateToString(Date date, String dateformat) {
String datestr = null;
SimpleDateFormat df = new SimpleDateFormat(dateformat);
datestr = df.format(date);
return datestr;
}
/**
* 获取日期的DAY值
*
*
* @param date
* 输入日期
* @return
*
*/
public static int getDayOfDate(Date date) {
int d = 0;
Calendar cd = Calendar.getInstance();
cd.setTime(date);
d = cd.get(Calendar.DAY_OF_MONTH);
return d;
}
/**
* 获取日期的MONTH值
*
*
* @param date
* 输入日期
* @return
*
*/
public static int getMonthOfDate(Date date) {
int m = 0;
Calendar cd = Calendar.getInstance();
cd.setTime(date);
m = cd.get(Calendar.MONTH) + 1;
return m;
}
/**
* 获取日期的YEAR值
*
*
* @param date
* 输入日期
* @return
*
*/
public static int getYearOfDate(Date date) {
int y = 0;
Calendar cd = Calendar.getInstance();
cd.setTime(date);
y = cd.get(Calendar.YEAR);
return y;
}
/**
* 获取星期几
*
*
* @param date
* 输入日期
* @return
*
*/
public static int getWeekOfDate(Date date) {
int wd = 0;
Calendar cd = Calendar.getInstance();
cd.setTime(date);
wd = cd.get(Calendar.DAY_OF_WEEK) - 1;
return wd;
}
/**
* 获取输入日期的当月第一天
*
*
* @param date
* 输入日期
* @return
*
*/
public static Date getFirstDayOfMonth(Date date) {
Calendar cd = Calendar.getInstance();
cd.setTime(date);
cd.set(Calendar.DAY_OF_MONTH, 1);
return cd.getTime();
}
/**
* 获得输入日期的当月最后一天
*
* @param date
*/
public static Date getLastDayOfMonth(Date date) {
return DateUtils.addDay(DateUtils.getFirstDayOfMonth(DateUtils.addMonth(date, 1)), -1);
}
/**
* 判断是否是闰年
*
*
* @param date
* 输入日期
* @return 是true 否false
*
*/
public static boolean isLeapYEAR(Date date) {
Calendar cd = Calendar.getInstance();
cd.setTime(date);
int year = cd.get(Calendar.YEAR);
if (year % 4 == 0 && year % 100 != 0 | year % 400 == 0) {
return true;
} else {
return false;
}
}
/**
* 根据整型数表示的年月日，生成日期类型格式
*
* @param year
* 年
* @param month
* 月
* @param day
* 日
* @return
*
*/
public static Date getDateByYMD(int year, int month, int day) {
Calendar cd = Calendar.getInstance();
cd.set(year, month-1, day);
return cd.getTime();
}
/**
* 获取年周期对应日
*
* @param date
* 输入日期
* @param iyear
* 年数 負數表示之前
* @return
*
*/
public static Date getYearCycleOfDate(Date date, int iyear) {
Calendar cd = Calendar.getInstance();
cd.setTime(date);
cd.add(Calendar.YEAR, iyear);
return cd.getTime();
}
/**
* 获取月周期对应日
*
* @param date
* 输入日期
* @param i
* @return
*
*/
public static Date getMonthCycleOfDate(Date date, int i) {
Calendar cd = Calendar.getInstance();
cd.setTime(date);
cd.add(Calendar.MONTH, i);
return cd.getTime();
}
/**
* 计算 fromDate 到 toDate 相差多少年
*
* @param fromDate
* @param toDate
* @return 年数
*
*/
public static int getYearByMinusDate(Date fromDate, Date toDate) {
Calendar df=Calendar.getInstance();
df.setTime(fromDate);
Calendar dt=Calendar.getInstance();
dt.setTime(toDate);
return dt.get(Calendar.YEAR)-df.get(Calendar.YEAR);
}
/**
* 计算 fromDate 到 toDate 相差多少个月
*
* @param fromDate
* @param toDate
* @return 月数
*
*/
public static int getMonthByMinusDate(Date fromDate, Date toDate) {
Calendar df=Calendar.getInstance();
df.setTime(fromDate);
Calendar dt=Calendar.getInstance();
dt.setTime(toDate);
return dt.get(Calendar.YEAR)*12+dt.get(Calendar.MONTH)-
(df.get(Calendar.YEAR)*12+df.get(Calendar.MONTH));
}
/**
* 计算 fromDate 到 toDate 相差多少天
*
* @param fromDate
* @param toDate
* @return 天数
*
*/
public static long getDayByMinusDate(Object fromDate, Object toDate) {
Date f=DateUtils.chgObject(fromDate);
Date t=DateUtils.chgObject(toDate);
long fd=f.getTime();
long td=t.getTime();
return (td-fd)/(24L * 60L * 60L * 1000L);
}
/**
* 计算年龄
*
* @param birthday
* 生日日期
* @param calcDate
* 要计算的日期点
* @return
*
*/
public static int calcAge(Date birthday, Date calcDate) {
int cYear=DateUtils.getYearOfDate(calcDate);
int cMonth=DateUtils.getMonthOfDate(calcDate);
int cDay=DateUtils.getDayOfDate(calcDate);
int bYear=DateUtils.getYearOfDate(birthday);
int bMonth=DateUtils.getMonthOfDate(birthday);
int bDay=DateUtils.getDayOfDate(birthday);
if(cMonth>bMonth||(cMonth==bMonth&&cDay>bDay)){
return cYear-bYear;
}else{
return cYear-1-bYear;
}
}
/**
* 从身份证中获取出生日期
*
* @param idno
* 身份证号码
* @return
*
*/
public static String getBirthDayFromIDCard(String idno) {
Calendar cd = Calendar.getInstance();
if (idno.length() == 15) {
cd.set(Calendar.YEAR, Integer.valueOf("19" + idno.substring(6, 8))
.intValue());
cd.set(Calendar.MONTH, Integer.valueOf(idno.substring(8, 10))
.intValue() - 1);
cd.set(Calendar.DAY_OF_MONTH,
Integer.valueOf(idno.substring(10, 12)).intValue());
} else if (idno.length() == 18) {
cd.set(Calendar.YEAR, Integer.valueOf(idno.substring(6, 10))
.intValue());
cd.set(Calendar.MONTH, Integer.valueOf(idno.substring(10, 12))
.intValue() - 1);
cd.set(Calendar.DAY_OF_MONTH,
Integer.valueOf(idno.substring(12, 14)).intValue());
}
return DateUtils.dateToString(cd.getTime());
}
/**
* 在输入日期上增加（+）或减去（-）天数
*
* @param date
* 输入日期
* @param imonth
* 要增加或减少的天数
*/
public static Date addDay(Date date, int iday) {
Calendar cd = Calendar.getInstance();
cd.setTime(date);
cd.add(Calendar.DAY_OF_MONTH, iday);
return cd.getTime();
}
/**
* 在输入日期上增加（+）或减去（-）月份
*
* @param date
* 输入日期
* @param imonth
* 要增加或减少的月分数
*/
public static Date addMonth(Date date, int imonth) {
Calendar cd = Calendar.getInstance();
cd.setTime(date);
cd.add(Calendar.MONTH, imonth);
return cd.getTime();
}
/**
* 在输入日期上增加（+）或减去（-）年份
*
* @param date
* 输入日期
* @param imonth
* 要增加或减少的年数
*/
public static Date addYear(Date date, int iyear) {
Calendar cd = Calendar.getInstance();
cd.setTime(date);
cd.add(Calendar.YEAR, iyear);
return cd.getTime();
}
/**
* 將OBJECT類型轉換為Date
* @param date
* @return
*/
public static Date chgObject(Object date){
if(date!=null&&date instanceof Date){
return (Date)date;
}
if(date!=null&&date instanceof String){
return DateUtils.stringToDate((String)date);
}
return null;
}
public static long getAgeByBirthday(String date){
Date birthday = stringToDate(date, "yyyy-MM-dd");
long sec = new Date().getTime() - birthday.getTime();
long age = sec/(1000*60*60*24)/365;
return age;
}
/**
* @param args
*/
public static void main(String[] args) {
//String temp = DateUtil.dateToString(getLastDayOfMonth(new Date()),
/// DateUtil.DATE_FORMAT_CHINESE);
//String s=DateUtil.dateToString(DateUtil.addDay(DateUtil.addYear(new Date(),1),-1));
long s=DateUtils.getDayByMinusDate("2012-01-01", "2012-12-31");
System.err.println(s);
}
}
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