Roll the days forward or backward in Java

/*ww  w .jav  a2  s. co m*/
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;

public class Main {
  /**
   * Roll the days forward or backward.
   * 
   * @param startDate
   *          - The start date
   * @param days
   *          - Negative to rollbackwards.
   */
  public static java.sql.Date rollDays(java.util.Date startDate, int days) {
    return rollDate(startDate, Calendar.DATE, days);
  }

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

  public static void main(String[] argv) {
    System.out.println(rollDays(new Date(), 10));
  }
}