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(20)

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>

<?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>

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();
    }
}

　　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);
}

　　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();
        }    
    }

}

　　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);
        }
    }

}