@XmlRootElement
public class PersistentInterval {

    private int numberOfSeats;
    private ArrayList<GregorianCalendar> startingIntervals;
    private ArrayList<GregorianCalendar> endingIntervals;

    @XmlElement
    public int getNumberOfSeats() {
        return numberOfSeats;
    }    

    @XmlElement
    public ArrayList<GregorianCalendar> getStartingIntervals() {
        return startingIntervals;
    }
    
    @XmlElement
    public ArrayList<GregorianCalendar> getEndingIntervals() {
        return endingIntervals;
    }
}