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用户管理系统，使用Hibernate向数据库表中添加一个用户，将所有的用户信息查出来并显示在页面上。
所需工具：MyEclipse、MySql数据库
新建一个数据库javaweb，并在该数据库下创建一个表USER并存入几条数据
DROP TABLE IF EXISTS `user`;CREATE TABLE `user` ( `id` int(11) NOT NULL AUTO_INCREMENT, `username` varchar(20) DEFAULT NULL, `password` varchar(20) DEFAULT NULL, `realname` varchar(50) DEFAULT NULL, `age` int(11) DEFAULT NULL, `sex` varchar(2) DEFAULT NULL, `address` varchar(50) DEFAULT NULL, PRIMARY KEY (`id`)) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8;INSERT INTO `user` VALUES ('1', '张三', '1111', '张三', '18', '男', '山东省');INSERT INTO `user` VALUES ('2', 'anna', '2017', 'anna', '19', '女', '美国'); ①直接向lib下导入所需的jar包②用myeclipse自带的jar包
在这里我使用了第二种方法：
配置Hibernate：在项目上点击右键-->MyEclipse-->Add Hibernate Capabilities...默认到最后一步配置MySql.配置好Hibernate，会自动生成hibernate.cfg.xml和HibernateSessionFactory文件，在src下新建common包将HibernateSessionFactory文件放到里面。
配置Struts2：在项目上点击右键-->MyEclipse-->Add Struts Capabilities..-->选择Struts2最高版本，URL Pattern选择/*-->Finish
在src目录下新建entity包，并创建Hibernate的POJO类User（普通的Java类作为持久化对象）
public class User { // 用户编号. private int id; // 用户名. private String username; // 密码. private String password; // 真实姓名. private String realname; // 年龄. private int age; // 性别. private String sex; // 地址. private String address; //属性的getter和setter方法省略。。。} Hibernate映射文件是要告诉Hibernate持久化类和数据库表的映射信息。
在entity中创建User.hbm.xml文件
Hibernate配置文件是告诉Hibernate连接的数据库的相关信息，数据库配置内容定义在hibernate.cfg.xml中。
hibernate.cfg.xmlcom.mysql.jdbc.Driver jdbc:mysql://localhost:3306/javaweb root 123456 org.hibernate.dialect.MySQLDialect
在该类中读取hibernae.cfg.xml配置文件。
代码如下
import org.hibernate.HibernateException;import org.hibernate.Session;import org.hibernate.cfg.Configuration;import org.hibernate.service.ServiceRegistry;import org.hibernate.service.ServiceRegistryBuilder;/** * Configures and provides access to Hibernate sessions, tied to the * current thread of execution. Follows the Thread Local Session * pattern, see {@link http://hibernate.org/42.html }. */public class HibernateSessionFactory { /** * Location of hibernate.cfg.xml file. * Location should be on the classpath as Hibernate uses * #resourceAsStream style lookup for its configuration file. * The default classpath location of the hibernate config file is * in the default package. Use #setConfigFile() to update * the location of the configuration file for the current session. */ private static final ThreadLocal threadLocal = new ThreadLocal (); private static org.hibernate.SessionFactory sessionFactory; private static Configuration configuration = new Configuration(); private static ServiceRegistry serviceRegistry; static { try { configuration.configure(); serviceRegistry = new ServiceRegistryBuilder().applySettings(configuration.getProperties()).buildServiceRegistry(); sessionFactory = configuration.buildSessionFactory(serviceRegistry); } catch (Exception e) { System.err.println("%%%% Error Creating SessionFactory %%%%"); e.printStackTrace(); } } private HibernateSessionFactory() { } /** * Returns the ThreadLocal Session instance. Lazy initialize * the SessionFactory if needed. * * @return Session * @throws HibernateException */ public static Session getSession() throws HibernateException { Session session = (Session) threadLocal.get(); if (session == null || !session.isOpen()) { if (sessionFactory == null) { rebuildSessionFactory(); } session = (sessionFactory != null) ? sessionFactory.openSession() : null; threadLocal.set(session); } return session; } /** * Rebuild hibernate session factory * */ public static void rebuildSessionFactory() { try { configuration.configure(); serviceRegistry = new ServiceRegistryBuilder().applySettings(configuration.getProperties()).buildServiceRegistry(); sessionFactory = configuration.buildSessionFactory(serviceRegistry); } catch (Exception e) { System.err.println("%%%% Error Creating SessionFactory %%%%"); e.printStackTrace(); } } /** * Close the single hibernate session instance. * * @throws HibernateException */ public static void closeSession() throws HibernateException { Session session = (Session) threadLocal.get(); threadLocal.set(null); if (session != null) { session.close(); } } /** * return session factory * */ public static org.hibernate.SessionFactory getSessionFactory() { return sessionFactory; } /** * return hibernate configuration * */ public static Configuration getConfiguration() { return configuration; }} 在src目录下新建一个包dao，创建UserDao类
import java.util.ArrayList;import java.util.List;import org.hibernate.Session;import com.zrx.common.HibernateSessionFactory;import com.zrx.entity.User;public class UserDao { //保存用户. public int saveUser(User user) { int num = 0; Session session = null; //由于Hibernate版本的差异，不能直接写Transaction transaction = null;要指定为org.hibernate.Transaction. org.hibernate.Transaction transaction = null; try { session = HibernateSessionFactory.getSession();//获取session对象. transaction = session.beginTransaction();//开启事务. num = Integer.parseInt(session.save(user).toString());//保存数据. transaction.commit();//提交事务. } catch (Exception e) { num = 0; e.printStackTrace(); } finally { HibernateSessionFactory.closeSession();//关闭session. } return num; } //查询全部的用户信息. @SuppressWarnings("unchecked") public List getUsers() { List users = new ArrayList (); try { Session session = HibernateSessionFactory.getSession();//获得session对象. //创建查询语句，字符串中的User必须与entity中的User实体类名称相同. users = session.createQuery("from User order by id").list(); } catch (Exception e) { e.printStackTrace(); } finally { HibernateSessionFactory.closeSession(); } return users; }} 在src下新建包action，在包下创建类UserAction
import java.util.List;import com.opensymphony.xwork2.ActionSupport;import com.zrx.dao.UserDao;import com.zrx.entity.User;public class UserAction extends ActionSupport { private static final long serialVersionUID = 1L; private User user; UserDao userDao = new UserDao(); private List userList; //保存用户. public String execute() { userDao.saveUser(user); return SUCCESS; } //获取用户. public String getUsers() { userList = userDao.getUsers(); return "list"; } public User getUser() { return user; } public void setUser(User user) { this.user = user; } public List getUserList() { return userList; }} / user getUsers /index.jsp