如何处理两个日期变量设置的上限和下限内的日期范围

Question

I have with me 2 dates in different date variables in a java desktop application. Now I want to create a loop that does some processing for each date within these 2 dates. (Excluding scenario where date= Upper bound value of date but including scenario where date=lower bound value of date).

I do understand basic usage of dates in java, I just want to know, is there any easy way of looping through all dates between these 2 dates, and then do some processing for each date?

Another question related to dates- how do I obtain only the current system date in java, as well as the year portion of a date variable (For getting year portion of a date do I have to put the entire value of date variable into a string variable and then extract relevant portion that represents year?)

Answer 1

Here is a sample: http://helpdesk.objects.com.au/java/how-can-i-iterate-through-all-dates-in-a-range

import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.Iterator;
import java.util.Map;

public class DateIterator
   implements Iterator<Date>, Iterable<Date>
{

    private Calendar end = Calendar.getInstance();
    private Calendar current = Calendar.getInstance();

    public DateIterator(Date start, Date end)
    {
        this.end.setTime(end);
        this.end.add(Calendar.DATE, -1);
        this.current.setTime(start);
        this.current.add(Calendar.DATE, -1);
    }

    public boolean hasNext()
    {
        return !current.after(end);
    }

    public Date next()
    {
        current.add(Calendar.DATE, 1);
        return current.getTime();
    }

    public void remove()
    {
        throw new UnsupportedOperationException(
           "Cannot remove");
    }

    public Iterator<Date> iterator()
    {
        return this;
    }

    public static void main(String[] args)
    {
        Date d1 = new Date();
        Calendar cal = Calendar.getInstance();
        cal.add(Calendar.DATE, 22);
        Date d2 = cal.getTime();

        Iterator<Date> i = new DateIterator(d1, d2);
        while(i.hasNext())
        {
            Date date = i.next();
            System.out.println(date);
        }
    }
}