java-date-calculate

inf:http://stackoverflow.com/questions/7103064/java-calculate-the-number-of-days-between-two-dates

import java.util.*;
 public class DateDifference {
 public static void main(String args[]){
 DateDifference difference = new DateDifference();
 }
 DateDifference() {
 Calendar cal1 = new GregorianCalendar();
 Calendar cal2 = new GregorianCalendar();

 cal1.set(2010, 12, 1); 
 cal2.set(2011, 9, 31);
 System.out.println("Days= "+daysBetween(cal1.getTime(),cal2.getTime()));
 }
 public int daysBetween(Date d1, Date d2){
 return (int)( (d2.getTime() - d1.getTime()) / (1000 * 60 * 60 * 24));
 }
 }

DTOC

java.util.Date dJ = new SimpleDateFormat("yyyy-MM-dd").parse("2012-12-31"); 
Calendar calJ = Calendar.getInstance();