日期计算
简单日期计算类：
日期大小比较
日期之间天数计算
日期大小比较
日期之间天数计算
package org.jf.alg;
/**
*
* @author junfeng.chen
*
*/
public class Date {
private int year;
private int month;
private int day;
private static final int days_array[]= {31,28,31,30,31,30,31,31,30,31,30,31};
private static final int days_leap_array[]= {31,29,31,30,31,30,31,31,30,31,30,31};
private static final String MONTH_NAME[] = {"January","Febuary", "March", "April", "May", "June", "July", "August", "September", "October","November","December"};
private static final String WEEK_NAME[] = {"Monday","Tuesday", "Wednesday","Thursday", "Friday","Saturday","Sunday"};
public Date(int year,int month,int day)
{
this.year = year;
boolean leap = Date.isLeapYear(this.year);
this.month = month;
if(this.month%12==0)
this.month = 12;
else this.month = this.month%12;
if(leap)
{
this.day = day%days_leap_array[this.month-1]==0?days_leap_array[this.month-1]:day%days_leap_array[this.month-1];//day<=days_leap_array[this.month-1]?day:days_leap_array[this.month-1];
}else
{
this.day = day%days_array[this.month-1]==0?days_array[this.month-1]:day%days_array[this.month-1];
}
}
public Date()
{
this.year = 1970;
this.month = 1;
this.day =1;
}
public int getYear() {
return year;
}
public void setYear(int year) {
this.year = year;
}
public int getMonth() {
return month;
}
public void setMonth(int month) {
this.month = month;
boolean leap = Date.isLeapYear(this.year);
if(this.month%12==0)
this.month = 12;
else this.month = this.month%12;
//check day
if(leap)
{
this.day = day%days_leap_array[this.month-1]==0?days_leap_array[this.month-1]:day%days_leap_array[this.month-1];//day<=days_leap_array[this.month-1]?day:days_leap_array[this.month-1];
}else
{
this.day = day%days_array[this.month-1]==0?days_array[this.month-1]:day%days_array[this.month-1];
}
}
public int getDay() {
return day;
}
/**
* date filed set seq --> year month day
* you should granted that year filed and month filed have set
* @param day
*/
public void setDay(int day) {
this.day = day;
boolean isleap = isLeapYear(year);
if(isleap)
{
this.day = day%days_leap_array[this.month-1]==0?days_leap_array[this.month-1]:day%days_leap_array[this.month-1];//day<=days_leap_array[this.month-1]?day:days_leap_array[this.month-1];
}else
{
this.day = day%days_array[this.month-1]==0?days_array[this.month-1]:day%days_array[this.month-1];
}
}
public Date addDay(int days)
{
if(days > 0)
{
//上补齐为本月末一天
int thismonthday = this.monthDays(this.month,isLeapYear(this));
int d = thismonthday - this.day;
if(days>=d)
{
this.day = thismonthday;
days = days - d;
}
else
{
this.day+=days;
days = 0;
}
while(days > 0)
{
int nextmonth = this.month+1;
int nextyear = this.year;
if(nextmonth>12)
{
nextmonth = 1;
nextyear += 1;
}
boolean ran = isLeapYear(nextyear);
int nextmonthday = this.monthDays(nextmonth,ran);
if(days>=nextmonthday)
{
this.month = nextmonth;
this.year = nextyear;
days -= nextmonthday;
this.day = nextmonthday;
}else
{
this.month = nextmonth;
this.day = days;
days = 0;
}
}
}else
{
days*=-1;
//下补齐为上月最后一天(如果可能)
if(this.day<=days)
{
days -= this.day;
int pre_year = this.year;
int pre_month =this.month-1;
if(pre_month == 0)
{
pre_month = 12;
pre_year -- ;
}
int pre_month_day = monthDays(pre_month,isLeapYear(pre_year));
this.year = pre_year;
this.month = pre_month;
this.day = pre_month_day;
}else
{
this.day -= days;
days = 0;
}
//按月递减
while(days>0)
{
int pre_month = this.month - 1;
int pre_year = year;
if(pre_month==0)
{
pre_month = 12;
pre_year = year -1;
}
int pre_month_day = this.monthDays(pre_month, isLeapYear(pre_year));
if(days>=this.day)
{
days -= this.day;
this.year = pre_year;
this.month = pre_month;
this.day = pre_month_day;
}else
{
this.day -= days;
days = 0;
}
}
}
return this;
}
/**
*
* @param months
* @return
*/
public Date addMonth(int months)
{
int addYear = months/12;
int addMonth = months%12;
if(months>0)
{
this.year += addYear;
this.month += addMonth;
if(this.month>12)
{
this.year ++;
this.month = this.month - 12;
}
}else
{
this.year +=addYear;
if(this.month+addMonth<=0)
{
this.year --;
this.month = 12 + this.month+addMonth;
}else
{
this.month += addMonth;
}
}
boolean isleap = isLeapYear(year);
if(isleap)
{
if(day>Date.days_leap_array[month-1])
day = Date.days_leap_array[month-1];
}
else
{
if(day>Date.days_array[month-1])
day = Date.days_array[month-1];
}
return this;
}
public Date addYear(int year)
{
this.year +=year;
boolean leap = Date.isLeapYear(this.year);
if(leap)
{
if(this.day > Date.days_leap_array[this.month-1])
this.day = Date.days_leap_array[this.month-1];
}else
{
if(this.day > Date.days_array[this.month-1])
this.day = Date.days_array[this.month-1];
}
return this;
}
@Deprecated
public static int daysBetween(Date date1,Date date2)
{
return date1.days() - date2.days();
}
public String weekDay()
{
int week_num = (day + 2*month + 3*(month+1)/5 + year + year/4 - year/100 + year/400) % 7;
return Date.WEEK_NAME[week_num];
}
public int dateDiff(Date date)
{
int nd , nm , ny; //new_day, new_month, new_year
int od , om , oy ; //old_day, oldmonth, old_year
nm = (date.month + 9) % 12;
ny = date.year - nm/10;
nd = 365*ny + ny/4 - ny/100 + ny/400 + (nm*306 + 5)/10 + (date.day - 1);
om = (month + 9) % 12;
oy = year - om/10;
od = 365*oy + oy/4 - oy/100 + oy/400 + (om*306 + 5)/10 + (day - 1);
return od - nd;
}
public int cmp(Date date)
{
if (this.year > date.year)
return 1;
else if (this.year == date.year) {
if (this.month > date.month)
return 1;
else if (this.month == date.month) {
if (this.day > date.day)
return 1;
else if (this.day == date.day)
return 0;
// return -1;
}
// return -1;
}
return -1;
}
public static boolean isLeapYear(int year)
{
return (year%4==0&&year%100!=0) || year%400 == 0;
}
public static boolean isLeapYear(Date date)
{
return (date.year%4==0&&date.year%100!=0) || date.year % 400 == 0 ;
}
private int monthDays(int month,boolean run)
{
if(run)
return days_leap_array[month-1];
return days_array[month-1];
}
public String toString()
{
return this.year+"-"+this.month+"-"+this.day;
}
int days()
{
int year = this.year;
int month = this.month;
int day = this.day;
int days = 0;
days += day;
month --;
if(month==0)
{
month = 12;
year --;
}
int monthday = this.monthDays(month, isLeapYear(year));
while(year>0)
{
days+=monthday;
month --;
if(month==0)
{
month = 12;
year --;
}
monthday = this.monthDays(month, isLeapYear(year));
}
return days;
}
}