19. DateUtils demo class

• The proposed DateUtils class represents common operations needed by business applications:

  
  import java.util.*;
  
  public class DateUtils {
      static final int MILLS_IN_DAY = 24 * 60 * 60 * 1000;
  
      // Returns Date with current date and removes time component
      public static Date getCurrentDate() {
          GregorianCalendar currentDate = 
              new GregorianCalendar();
          currentDate.set( Calendar.HOUR, 0 );
          currentDate.set( Calendar.MINUTE, 0 );
          currentDate.set( Calendar.SECOND, 0 );
          return currentDate.getTime();
      }
  
      // Returns Date for the specified date
      public static Date createDate(
          int year, int month, int day
          )
      {
          GregorianCalendar date = 
              new GregorianCalendar( year, month, day );
          return date.getTime();
      }
  
      // Returns Date with the time component removed
      public static Date stripTime( Date date )
      {
          GregorianCalendar currentDate = 
              new GregorianCalendar();
          currentDate.setTime( date );
          currentDate.set( Calendar.HOUR, 0 );
          currentDate.set( Calendar.MINUTE, 0 );
          currentDate.set( Calendar.SECOND, 0 );
          return currentDate.getTime();
      }
  
      // Calculates diff between two Date objects in days
      public static int daysDiff( Date date1, Date date2 )
      {
          date1 = stripTime( date1 );
          date2 = stripTime( date2 );
          long longDate1 = date1.getTime();
          long longDate2 = date2.getTime();
          long longDiff = longDate2 - longDate1;
          return ( int ) ( longDiff / MILLS_IN_DAY );
      }
  }// class DateUtils