Get the hours difference in Java

//from  www  .j a v a  2 s  .c o  m
import java.util.Calendar;
import java.util.Date;

public class Main {

  public final static long SECOND_MILLIS = 1000;
  public final static long MINUTE_MILLIS = SECOND_MILLIS * 60;
  public final static long HOUR_MILLIS = MINUTE_MILLIS * 60;

  /**
   * Get the hours difference
   */
  public static int hoursDiff(Date earlierDate, Date laterDate) {
    if (earlierDate == null || laterDate == null)
      return 0;

    return (int) ((laterDate.getTime() / HOUR_MILLIS) - (earlierDate.getTime() / HOUR_MILLIS));
  }

  public static void main(String[] argv) {
    Date date1 = Calendar.getInstance().getTime();
    Calendar cal = Calendar.getInstance();
    cal.set(2010, 10, 10);
    Date date2 = cal.getTime();
    System.out.println(hoursDiff(date1, date2));
  }
}