java – 嵌套类的公共构造函数

public class MyPromosResponse extends BaseResponse {

    public MyPromosResponseData response;

    public MyPromosResponse() {
    }

    public TreeSet<Promo> getMyPromosResponseData() {
        return new TreeSet<Promo>(response.getEvents());
    }

    @JsonIgnoreProperties(ignoreUnknown = true)
    class MyPromosResponseData {
        public ArrayList<Promo> events;
        public ArrayList<Table1PromoData> Table1;

        public MyPromosResponseData() {
        }

        public ArrayList<Promo> getEvents() {
            return events;
        }

        ArrayList<Table1PromoData> getTable1() {
            return Table1;
        }

    }

    class Table1PromoData {
        public int id;
        public int eventid;
        public int cardholderid;

        public Table1PromoData() { // Here is the constructor.
        }

        public int getId() {
            return id;
        }

        public void setId(int id) {
            this.id = id;
        }

        public int getEventid() {
            return eventid;
        }

        public void setEventid(int eventid) {
            this.eventid = eventid;
        }

        public int getCardholderid() {
            return cardholderid;
        }

        public void setCardholderid(int cardholderid) {
            this.cardholderid = cardholderid;
        }
    }

}

当我将Table1PromoData作为嵌套类时,我有错误,无法找到默认构造函数,但是定义了一个公共构造函数.如果我将它移动到一个单独的文件一切都很好 – lib找到构造函数.

将默认构造函数移动到单独的文件后,为什么默认构造函数可见？