I'm trying to compare two dates together and I only want to compare the date part not the time part this is how I store date inside my program :
Thu Jan 27 23:20:00 GMT 2011
I have an:
ArrayList<Date> dateList;
and I want to use
dateList.compares(newDate);
// if the answer was false which means I
// have new date then add the newdate to my list
but since the time part also is involved I can't get the proper answer. How can I fix my problem?
I don't want use JODA-TIME
You can compare value by value like this
d1.getDate().equals(d2.getDate()) &&
d1.getYear().equals(d2.getYear()) &&
d1.getMonth().equals(d2.getMonth())
Or
Date date1 = new Date(d1.getYear(), d1.getMonth(), d1.getDate());
Date date2 = new Date(d2.getYear(), d2.getMonth(), d2.getDate());
date1.compareTo(date2);
If you work with Date class, consider using Calendar class instead Here's the most elegant solution, using Calendar and Comparator for this
public class CalendarDateWithoutTimeComparator implements Comparator<Calendar> {
public int compare(Calendar cal1, Calendar cal2) {
if(cal1.get(Calendar.YEAR) != cal2.get(Calendar.YEAR)) {
return cal1.get(Calendar.YEAR) - cal2.get(Calendar.YEAR);
} else if (cal1.get(Calendar.MONTH) != cal2.get(Calendar.MONTH)) {
return cal1.get(Calendar.MONTH) - cal2.get(Calendar.MONTH);
}
return cal1.get(Calendar.DAY_OF_MONTH) - cal2.get(Calendar.DAY_OF_MONTH);
}
}
Usage:
Calendar c1 = Calendar.getInstance();
Calendar c2 = Calendar.getInstance();
// these calendars are equal
CalendarDateWithoutTimeComparator comparator = new CalendarDateWithoutTimeComparator();
System.out.println(comparator.compare(c1, c2));
List<Calendar> list = new ArrayList<Calendar>();
list.add(c1);
list.add(c2);
Collections.sort(list, comparator);
Why dont you use compareTo()?
int java.util.Date#compareTo(Date anotherDate)
Date check_in = new Date(2010,7,31);
Date check_out = new Date(2011,5,22);
int result = check_out.compareTo(check_in);
if(result<0)
{
// check_out < check_in
}
else if(result>0)
{
// check_out > check_in
}
else
{
// check_out == check_in
}
You can use this
int compareDates(Calendar c1, Calendar c2) {
if(c1.get(Calendar.YEAR) != c2.get(Calendar.YEAR)){
return c1.get(Calendar.YEAR) - c2.get(Calendar.YEAR);
} else if(c1.get(Calendar.MONTH) != c2.get(Calendar.MONTH)){
return c1.get(Calendar.MONTH) - c2.get(Calendar.MONTH);
}
return (c1.get(Calendar.DAY_OF_MONTH) - c2.get(Calendar.DAY_OF_MONTH));
}
EDIT:
Joda time or no this SO post has all answers for date comparison
