Convert java.util.Date to java.sql.Time after calculation

import java.util.GregorianCalendar;

public class Main {
  /**
   * Add the java.util.Time forward or backward.
   * @param startDate - The start date
   * @period Calendar.YEAR etc
   * @param amount - Negative to roll backwards.
   */
   public static java.sql.Time rollTime( java.util.Date startDate, int period, int amount )
   {
       GregorianCalendar gc = new GregorianCalendar();
       gc.setTime(startDate);
       gc.add(period, amount);
       return new java.sql.Time(gc.getTime().getTime());
   }
}