Date in miliseconds

Question

hi,
i try to store current date value as integer in my database so i will be able to compare dates by sql command simply like comparing integer values. this is the method i use when i code in PHP. so for this purpose i use Date classes getTime() method to get the time in miliseconds. but i want to ignore hour,minute,second,milisecond values. i need only day,month and year in miliseconds. but how?
also how can i reverse the process to get day,month and year from such milisecond representation?
thaks for your helps...

Answer 1

Try this one :))
import java.util.Calendar;
import java.util.Date;
public class DateConverter {
  Calendar calendar;
     public DateConverter() {
          this( Calendar.getInstance() );
  public DateConverter( Calendar cal ) {
    super();
    calendar = cal;
  public long toMillis( Date d ) {
    long result = -1;
    calendar.clear();
    calendar.setTime( d );
    clearTime();
    result = calendar.getTime().getTime();
    return result;
  private void clearTime() {
    calendar.set( Calendar.HOUR, 0 );
    calendar.set( Calendar.MINUTE, 0 );
    calendar.set( Calendar.SECOND, 0 );
    calendar.set( Calendar.MILLISECOND, 0 );
  public Date toDate( long millis ) {
    Date result;
    result = new Date( millis );
    calendar.clear();
    calendar.setTime( result );
    clearTime();
    result = calendar.getTime();
    return result;
  public static void main(String[] args) {
    DateConverter conv = new DateConverter();
    Date now = new Date();
    System.out.println( "Now is " + now + "\n -> millis " + now.getTime() );
    System.out.println( " -> becomes " + conv.toMillis( now ) );
    System.out.println( " -> as Date " + conv.toDate( conv.toMillis( now ) ) );
    long then = System.currentTimeMillis();
    System.out.println( "Then is " + then + "\n -> Date " + new Date( then ) );
    System.out.println( " -> becomes " + conv.toDate( then ) );
    System.out.println( " -> as millis " + conv.toMillis( conv.toDate( then ) ) );
}Delivers:
Now is Thu Jan 02 12:34:36 GMT+01:00 2003
-> millis 1041507276338
-> becomes 1041505200000
-> as Date Thu Jan 02 12:00:00 GMT+01:00 2003
Then is 1041507276598
-> Date Thu Jan 02 12:34:36 GMT+01:00 2003
-> becomes Thu Jan 02 12:00:00 GMT+01:00 2003
-> as millis 1041505200000