public boolean isExistPrePage() {
        return existPrePage;
    }

    public void setExistPrePage(final boolean existPrePage) {
        this.existPrePage = existPrePage;
    }

    public boolean isExistNextPage() {
        return existNextPage;
    }

    public void setExistNextPage(final boolean existNextPage) {
        this.existNextPage = existNextPage;
    }

    public int getPageSize() {