hibernate搭建及其增删改查

一、jar包

　　最基础的hibernatejar包，以及数据库驱动的jar包

　　

二、数据库

 　t_user表
      id  int  主键  自动增长
      name varchar()

三、配置文件

 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE hibernate-configuration PUBLIC
     "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
     "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
 <hibernate-configuration>
     <session-factory>
         <!--  配置数据库信息 -->
         <property name="hibernate.connection.username">root</property>
         <property name="hibernate.connection.password">mysql123</property>
         <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
         <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/hibernate_test</property>
         <property name="hibernate.connection.autocommit">true</property>

         <property name="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</property>
         <property name="hibernate.hbm2ddl.auto">update</property>
         <!-- 显示生成的sql语句 -->
         <property name="hibernate.show_sql">true</property>

         <mapping resource="cn/itcast/domain/User.hbm.xml"/>
     </session-factory>
 </hibernate-configuration>

hibernate.cfg.xml

 <?xml version="1.0"?>
 <!DOCTYPE hibernate-mapping PUBLIC
     "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
     "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
 <hibernate-mapping package="cn.itcast.domain">
     <class name="User" table="t_user">
         <id name="id" type="int">
             <generator class="native" />
         </id>
         <property name="name" type="string"/>
     </class>
 </hibernate-mapping>

Uesr.hbm.xml

四、程序

　　1、主要是负责session的开启，属于模板代码

 package cn.itcast.domain.dao;

 import org.hibernate.Session;
 import org.hibernate.SessionFactory;
 import org.hibernate.cfg.Configuration;

 public class HibernateUtils {

     private static SessionFactory sessionFactory;
     static{
         sessionFactory=new Configuration()
                     .configure()
                     .buildSessionFactory();
     }
     public static SessionFactory getSessionFactory(){
         return sessionFactory;
     }
     public static Session openSession(){
         return sessionFactory.openSession();
     }
 }

HibernateUtils.java

　　2、定义一个接口，声明增删改查的方法

 package cn.itcast.domain.dao;

 import java.util.List;
 import cn.itcast.domain.User;

 public interface UserDao {

     public void save(User user);
     public void update(User user);
     public void delete(int id);
     public User getById(int id);
     public List<User> findAll();
     public QueryResult findAll(int firstNumber, int maxNumber);
 }

UserDao.java

　　3、对接口创建实现类

 package cn.itcast.domain.dao;

 import java.util.List;

 import org.hibernate.Session;
 import org.hibernate.Transaction;
 import cn.itcast.domain.User;

 public class UserDaoImpl implements UserDao {

     @Override
     public void save(User user) {
         // TODO Auto-generated method stub
         Session session = HibernateUtils.openSession();
         Transaction tx= null;
         try{
             tx=session.beginTransaction();
             session.save(user);
             tx.commit();
         }catch(RuntimeException exception){
             tx.rollback();
             throw exception;
         }finally{
             session.close();
         }
     }

     @Override
     public void update(User user) {
         // TODO Auto-generated method stub
         Session session = HibernateUtils.openSession();
         Transaction tx=null;
         try{
             tx=session.beginTransaction();
             session.update(user);
             tx.commit();
         }catch(RuntimeException exception){
             tx.rollback();
             throw exception;
         }finally{
             session.close();
         }
     }

     @Override
     public void delete(int id) {
         // TODO Auto-generated method stub
         Session session = HibernateUtils.openSession();
         Transaction tx= null;
         try{
             tx=session.beginTransaction();
             Object user = session.get(User.class, id);
             session.delete(user);
             tx.commit();
         }catch(RuntimeException exception){
             tx.rollback();
             throw exception;
         }finally{
             session.close();
         }
     }

     @Override
     public User getById(int id) {
         // TODO Auto-generated method stub
         Session session = HibernateUtils.openSession();
         Transaction tx= null;
         try{
             tx=session.beginTransaction();
             User user =(User) session.get(User.class, id);
             tx.commit();
             return user;
         }catch(RuntimeException exception){
             tx.rollback();
             throw exception;
         }finally{
             session.close();
         }
     }

     @Override
     public List<User> findAll() {
         // TODO Auto-generated method stub
         Session session = HibernateUtils.openSession();
         Transaction tx= null;
         try{
             tx=session.beginTransaction();
             List<User> user = session.createQuery(" FROM User").list();
             tx.commit();
             return user;
         }catch(RuntimeException exception){
             tx.rollback();
             throw exception;
         }finally{
             session.close();
         }
     }

     /**
      * 分页查询
      */
     @Override
     public QueryResult findAll(int firstNumber, int maxNumber) {
         // TODO Auto-generated method stub
         Session session = HibernateUtils.openSession();
         Transaction tx= null;
         try{
             tx=session.beginTransaction();
             List<User> list = session.createQuery(" FROM User")
                     .setFirstResult(firstNumber)
                     .setMaxResults(maxNumber)
                     .list();

             Long count = (Long) session.createQuery("SELECT COUNT(*) FROM User").uniqueResult();
             tx.commit();
             return new QueryResult(count.intValue(),list);
         }catch(RuntimeException exception){
             tx.rollback();
             throw exception;
         }finally{
             session.close();
         }
     }

 }

UserDaoImpl.java

　　4、做一个测试类

 package cn.itcast.domain.dao;

 import java.util.List;

 import org.junit.Test;

 import cn.itcast.domain.User;

 public class TestUserDao {

     private UserDao userDao = new UserDaoImpl();

     @Test
     public void testSave_1() {
         User user = new User();
         user.setName("张三");

         // 保存
         userDao.save(user);
     }

     @Test
     public void testGetById() {
         User user = userDao.getById(1);
         System.out.println(user);
     }

     @Test
     public void testUpdate() {
         // 从数据库获取一条存在的数据
         User user = userDao.getById(1);
         user.setName("李四");

         // 更新
         userDao.update(user);
     }

     @Test
     public void testDelete() {
         userDao.delete(1);
     }

     // ------------

     @Test
     public void testSave_25() {
         for (int i = 1; i <= 25; i++) {
             User user = new User();
             user.setName("test_" + i);
             userDao.save(user); // 保存
         }
     }

     @Test
     public void testFindAll() {
         List<User> list = userDao.findAll();
         for (User user : list) {
             System.out.println(user);
         }
     }

     @Test
     public void testFindAllIntInt() {
         // 查询
         // QueryResult qr = userDao.findAll(0, 10); // 第1页，每页10条
         // QueryResult qr = userDao.findAll(10, 10); // 第2页，每页10条
         QueryResult qr = userDao.findAll(20, 10); // 第3页，每页10条

         // 显示结果
         System.out.println("总记录数：" + qr.getCount());
         for (User user : (List<User>) qr.getList()) {
             System.out.println(user);
         }
     }

 }

TestUserDao.java