javax/xml/bind/JAXBException

Question

我使用 Eclipse 创建了动态项目。在这个项目中，我为 mysql 数据库添加了休眠配置。我正在使用 servlet 进行 crud 操作。我知道在 Maven 项目中可以添加所需的依赖项，但不能为 Web 应用程序添加。我已将 Java.persistance jar 文件添加到 lib 文件夹中。这是项目结构。。

这是 Hibernate 代码。

package net.javaguides.usermanagement.utl;

import java.util.Properties;

import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;
import org.hibernate.cfg.Environment;
import org.hibernate.service.ServiceRegistry;

import net.javaguides.usermanagement.model.User;

/**
 * Java based configuration
 * @author ramesh Fadatare
 *
 */
public class HibernateUtil {
 private static SessionFactory sessionFactory;

 public static SessionFactory getSessionFactory() {
  if (sessionFactory == null) {
   try {
    Configuration configuration = new Configuration();

    // Hibernate settings equivalent to hibernate.cfg.xml's properties
    Properties settings = new Properties();
    settings.put(Environment.DRIVER, "com.mysql.jdbc.Driver");
    settings.put(Environment.URL, "jdbc:mysql://localhost:3306/demo?useSSL=false");
    settings.put(Environment.USER, "root");
    settings.put(Environment.PASS, "");
    settings.put(Environment.DIALECT, "org.hibernate.dialect.MySQL5Dialect");

    settings.put(Environment.SHOW_SQL, "true");

    settings.put(Environment.CURRENT_SESSION_CONTEXT_CLASS, "thread");

    settings.put(Environment.HBM2DDL_AUTO, "create-drop");

    configuration.setProperties(settings);
    configuration.addAnnotatedClass(User.class);

    ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder()
      .applySettings(configuration.getProperties()).build();
    System.out.println("Hibernate Java Config serviceRegistry created");
    sessionFactory = configuration.buildSessionFactory(serviceRegistry);
    return sessionFactory;

   } catch (Exception e) {
    e.printStackTrace();
   }
  }
  return sessionFactory;
 }
}

这是 servlet。

package net.javaguides.usermanagement.web;

import java.io.IOException;
import java.sql.SQLException;
import java.util.List;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import net.javaguides.usermanagement.dao.UserDao;
import net.javaguides.usermanagement.model.User;

/**
 * ControllerServlet.java
 * This servlet acts as a page controller for the application, handling all
 * requests from the user.
 * @email Ramesh Fadatare
 */

@WebServlet("/")
public class UserServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
    private UserDao userDao;

    public void init() {
        userDao = new UserDao();
    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        doGet(request, response);
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        String action = request.getServletPath();

        try {
            switch (action) {
                case "/new":
                    showNewForm(request, response);
                    break;
                case "/insert":
                    insertUser(request, response);
                    break;
                case "/delete":
                    deleteUser(request, response);
                    break;
                case "/edit":
                    showEditForm(request, response);
                    break;
                case "/update":
                    updateUser(request, response);
                    break;
                default:
                    listUser(request, response);
                    break;
            }
        } catch (SQLException ex) {
            throw new ServletException(ex);
        }
    }

    private void listUser(HttpServletRequest request, HttpServletResponse response)
    throws SQLException, IOException, ServletException {
        List < User > listUser = userDao.getAllUser();
        request.setAttribute("listUser", listUser);
        RequestDispatcher dispatcher = request.getRequestDispatcher("user-list.jsp");
        dispatcher.forward(request, response);
    }

    private void showNewForm(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        RequestDispatcher dispatcher = request.getRequestDispatcher("user-form.jsp");
        dispatcher.forward(request, response);
    }

    private void showEditForm(HttpServletRequest request, HttpServletResponse response)
    throws SQLException, ServletException, IOException {
        int id = Integer.parseInt(request.getParameter("id"));
        User existingUser = userDao.getUser(id);
        RequestDispatcher dispatcher = request.getRequestDispatcher("user-form.jsp");
        request.setAttribute("user", existingUser);
        dispatcher.forward(request, response);

    }

    private void insertUser(HttpServletRequest request, HttpServletResponse response)
    throws SQLException, IOException {
        String name = request.getParameter("name");
        String email = request.getParameter("email");
        String country = request.getParameter("country");
        User newUser = new User(name, email, country);
        userDao.saveUser(newUser);
        response.sendRedirect("list");
    }

    private void updateUser(HttpServletRequest request, HttpServletResponse response)
    throws SQLException, IOException {
        int id = Integer.parseInt(request.getParameter("id"));
        String name = request.getParameter("name");
        String email = request.getParameter("email");
        String country = request.getParameter("country");

        User user = new User(id, name, email, country);
        userDao.updateUser(user);
        response.sendRedirect("list");
    }

    private void deleteUser(HttpServletRequest request, HttpServletResponse response)
    throws SQLException, IOException {
        int id = Integer.parseInt(request.getParameter("id"));
        userDao.deleteUser(id);
        response.sendRedirect("list");
    }
}

这是我运行应用程序时的结果。

Answer 1

正如@andrewjames 所指出的，您需要下载 JAXB-API 库和一个实现，它们是 Hibernate 所必需的。

虽然您不使用 Maven 进行依赖管理，但您可以通过单击 jar link 下载相应的工件，您可以在 Files 行中找到 HTML table神器页面呈现

您需要下载：

JAXB-API
一个JAXB Runtime，例如Glassfish的参考实现。

您的依赖项中已经有 javax.activation。 JAXB 需要它-API.

javax/xml/bind/JAXBException

javax/xml/bind/JAXBException

java

hibernate

servlets