●プログラム・リスト●

// ※サーブレットに追記
import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Root;

@Override
protected void doGet(HttpServletRequest request,
        HttpServletResponse response)
        throws ServletException, IOException {
    EntityManager manager = factory.createEntityManager();
    CriteriaBuilder builder = manager.getCriteriaBuilder();
    CriteriaQuery<MyDataEntity> criteria_query =
            builder.createQuery(MyDataEntity.class);
    Root<MyDataEntity> root = criteria_query.from(MyDataEntity.class);
    criteria_query.select(root).orderBy(builder.desc(root.get("id").as(Integer.class)));
    Query query = manager.createQuery(criteria_query);
    List list = query.getResultList();
    request.setAttribute("list", list);
    RequestDispatcher dispatcher = request.getRequestDispatcher("index.jsp");
    dispatcher.forward(request,response);
}