java Date range Iterator

Tree easy steps to create your own Date Iterator to iterate though some date range.

Step 1: Implement java.util.Iterator & java.lang.Iterable interfaces
Step 2: implment the interface methods.
Step 3: start using your newly created class.


Below is a simple example:
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package com.kal.util;

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

public class DateIterator implements Iterator, Iterable {

private Calendar end = null;
private Calendar start = null;

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

//This has the condition to check whether start date has reached end date.
public boolean hasNext() {
return !start.after(end);
}

//increments one day.
public Date next() {
start.add(Calendar.DATE, 1);
return start.getTime();
}

//Either throw an exception or make it empty.
public void remove() {
throw new UnsupportedOperationException("Remove not supported");
}

public Iterator iterator() {
return this;
}


public static void main(String[] args) {

//For example, start date = end date - 1 month
Calendar cal = Calendar.getInstance();
cal.set(Calendar.MONTH, cal.get(Calendar.MONTH)-1);
Date startDate = cal.getTime();

Date endDate = new Date();

DateIterator itr = new DateIterator(startDate, endDate);

//This loop prints the last one month dates
while(itr.hasNext()) {
System.out.println(itr.next());
}
}
}