JAVA computes two instances whose dates differ
- 2020-04-01 02:27:59
- OfStack
Data that is more than a few days apart is used when Java is developing logistics or other features, so I've sorted it out.
Method of invocation:
long date1 = getDateTime("20121201");//Can be changed to your own date type, but in the format of "20121212"
long date2 = getDateTime("20121212");
int day = dateInterval(date1, date2);
System.out.println(day);
Method invocation:
public static int dateInterval(long date1, long date2) {
if(date2 > date1){
date2 = date2 + date1;
date1 = date2 - date1;
date2 = date2 - date1;
}
//The Canlendar class is an abstract class & NBSP;
//Provides a rich calendar field & PI;
//& NBSP; is used in this program;
//Calendar. YEAR Year & NBSP; of the date;
//Calendar. DAY_OF_YEAR Days of the current year & NBSP;
//GetActualMaximum (calendar.day_of_year) returns 365 days or 366 days & mailed this year;
Calendar calendar1 = Calendar.getInstance(); //Get a calendar & NBSP;
calendar1.setTimeInMillis(date1); //Set the current and previous time value of this Calendar with the given long value.
Calendar calendar2 = Calendar.getInstance();
calendar2.setTimeInMillis(date2);
//Judge the year first & cake;
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){
day = numerical(maxDays, d1, d2, y1, y2, calendar2);
}else{
day = d1 - d2;
}
return day;
}
public static int numerical(int maxDays, int d1, int d2, int y1, int y2, Calendar calendar){
int day = d1 - d2;
int betweenYears = y1 - y2;
List<Integer> d366 = new ArrayList<Integer>();
if(calendar.getActualMaximum(Calendar.DAY_OF_YEAR) == 366){
System.out.println(calendar.getActualMaximum (Calendar.DAY_OF_YEAR));
day += 1;
}
for (int i = 0; i < betweenYears; i++) {
//Year + 1 sets the number of days in the next year & NBSP;
calendar.set(Calendar.YEAR, (calendar.get (Calendar.YEAR)) + 1);
maxDays = calendar.getActualMaximum (Calendar.DAY_OF_YEAR);
//The first 366 days do not include all 366 records without + 1, no addition and then minus an & PI;
if(maxDays != 366){
day += maxDays;
}else{
d366.add(maxDays);
}
//If the last maxDays equals 366 day - 1& NBSP;
if(i == betweenYears-1 && betweenYears > 1 && maxDays == 366){
day -= 1;
}
}
for(int i = 0; i < d366.size(); i++){
//One or more 366 days & NBSP;
if(d366.size() >= 1){
day += d366.get(i);
}
}
return day;
}
public static long getDateTime(String strDate) {
return getDateByFormat(strDate, "yyyyMMdd").getTime();
}
public static Date getDateByFormat(String strDate, String format) {
SimpleDateFormat sdf = new SimpleDateFormat(format);
try{
return (sdf.parse(strDate));
}catch (Exception e){
return null;
}
}
Case 2
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
public class test16 {
public static void main(String[] args) throws ParseException {
// TODO Auto-generated method stub
SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Date d1=sdf.parse("2012-09-08 10:10:10");
Date d2=sdf.parse("2012-09-15 00:00:00");
System.out.println(daysBetween(d1,d2));
System.out.println(daysBetween("2012-09-08 10:10:10","2012-09 -15 00:00:00"));
}
public static int daysBetween(Date smdate,Date bdate) throws ParseException
{
SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM- dd");
smdate=sdf.parse(sdf.format(smdate));
bdate=sdf.parse(sdf.format(bdate));
Calendar cal = Calendar.getInstance();
cal.setTime(smdate);
long time1 = cal.getTimeInMillis ();
cal.setTime(bdate);
long time2 = cal.getTimeInMillis ();
long between_days=(time2-time1)/ (1000*3600*24);
return Integer.parseInt(String.valueOf (between_days));
}
public static int daysBetween(String smdate,String bdate) throws ParseException{
SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM- dd");
Calendar cal = Calendar.getInstance();
cal.setTime(sdf.parse(smdate));
long time1 = cal.getTimeInMillis ();
cal.setTime(sdf.parse(bdate));
long time2 = cal.getTimeInMillis ();
long between_days=(time2-time1)/ (1000*3600*24);
return Integer.parseInt(String.valueOf (between_days));
}
}
Example 3
//Get the remaining days
SimpleDateFormat df=new SimpleDateFormat("yyyymmdd");
Date d0=new java.util.Date();
Date d1=df.parse(end_date);
long time0=d0.getTime();
long time1=d1.getTime();
System.out.println((time1-time0)/(1000*60*60*24));
This is a good way to calculate the number of days between the two times
public static int diffdates(Date date1, Date date2) {
int result = 0;
ElapsedTime et = new ElapsedTime();
GregorianCalendar gc1 = new GregorianCalendar ();
GregorianCalendar gc2 = new GregorianCalendar ();
gc1.setTime(date1);
gc2.setTime(date2);
result = et.getDays(gc1, gc2);
return result;
}
Then the method in ElapseTime is:
public int getDays(GregorianCalendar g1, GregorianCalendar g2) {
int elapsed = 0;
GregorianCalendar gc1, gc2;
if (g2.after(g1)) {
gc2 = (GregorianCalendar) g2.clone();
gc1 = (GregorianCalendar) g1.clone();
} else {
gc2 = (GregorianCalendar) g1.clone();
gc1 = (GregorianCalendar) g2.clone();
}
gc1.clear(Calendar.MILLISECOND);
gc1.clear(Calendar.SECOND);
gc1.clear(Calendar.MINUTE);
gc1.clear(Calendar.HOUR_OF_DAY);
gc2.clear(Calendar.MILLISECOND);
gc2.clear(Calendar.SECOND);
gc2.clear(Calendar.MINUTE);
gc2.clear(Calendar.HOUR_OF_DAY);
while (gc1.before(gc2)) {
gc1.add(Calendar.DATE, 1);
elapsed++;
}
return elapsed;
}
It's actually easiest to use joda
public boolean isRentalOverdue(DateTime datetimeRented) {
Period rentalPeriod = Period.days(2);
return datetimeRented.plus(rentalPeriod).isBeforeNow()
}