本次学习版本：hibernate-release-5.2.6.Final，要求java 1.8 和JDBC 4.2。
hibernate是一个开放源代码的对象关系映射框架。对JDBC进行了非常轻量的封装。它将POJO与数据库表建立映射关系，是一个全自动的orm框架，hibernate可以自动生成SQL语句，自动执行，使得Java程序员可以随心所欲的使用对象编程思维来操纵数据库
hibernate可以在官网直接下载。
那么就来看用hibernate实现的一个Hello World的实例。
package com.fuwh.model;//这是一个实体类public class Helloworld { ???????private long id; ???private String helloWorld; ???public long getId() { ???????return id; ???} ???public void setId(long id) { ???????this.id = id; ???} ???public String getHelloWorld() { ???????return helloWorld; ???} ???public void setHelloWorld(String helloWorld) { ???????this.helloWorld = helloWorld; ???} ???????}<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"><!-- 这是实体类和表的映射关系的配置文件 --><hibernate-mapping package="com.fuwh.model"> ???<class name="Helloworld" table="t_helloworld"> ???????<id name="id" type="long"> ???????????<generator class="native"></generator> ???????</id> ???????<property name="helloWorld" column="helloworld"/> ???</class></hibernate-mapping>
<?xml version=‘1.0‘ encoding=‘utf-8‘?><!DOCTYPE hibernate-configuration PUBLIC"-//Hibernate/Hibernate Configuration DTD//EN""http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd"> <hibernate-configuration> ???????<session-factory> ???????<!-- 数据库连接设置 --> ???????<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property> ???????<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/hibernate</property> ???????<property name="hibernate.connection.username">root</property> ???????<property name="hibernate.connection.password">mysqladmin</property> ???????<!-- ????????????指定方言，表明用的是哪种数据库，也可以不指定，hibernate默认会翻译成正确的数据库脚本 ???????????方言可以在 hibernate-release-xx.xx/project/etc/hibernate.properties 中查找 ????????--> ???????<property name="hibernate.dialect">MySQL5</property> ???????<!-- 设定时候更新表结构，不存在或自动创建 --> ???????<property name="hibernate.hbm2ddl.auto">update</property> ???????<!-- 配置 在后台打印出sql语句 --> ???????<property name="show_sql">true</property> ??????<!-- 引入实体类和表的映射文件 --> ???????<mapping resource="com/fuwh/model/Helloworld.hbm.xml"/> ???</session-factory> ???</hibernate-configuration>
使用JUNIT的单体测试实例
package com.fuwh.service;import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.boot.MetadataSources;import org.hibernate.boot.registry.StandardServiceRegistry;import org.hibernate.boot.registry.StandardServiceRegistryBuilder;import org.junit.After;import org.junit.Before;import org.junit.Test;import com.fuwh.model.Helloworld;public class JunitTest { ???????private SessionFactory sessionFactory; ???????@Before ???public void setUp() throws Exception { ???????final StandardServiceRegistry serviceRegistry=new StandardServiceRegistryBuilder() ???????????????????????????????????????????????????????.configure() ???//读取hibernate.cfg.xml文件 ???????????????????????????????????????????????????????.build(); ???????try { ???????????sessionFactory=new MetadataSources(serviceRegistry).buildMetadata().buildSessionFactory(); ???????} catch (Exception e) { ???????????// TODO: handle exception ???????????System.out.println(e); ???????????StandardServiceRegistryBuilder.destroy(serviceRegistry); ???????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????} ???} ???@After ???public void tearDown() throws Exception { ???????if ???(sessionFactory != ???null){ ???????????sessionFactory.close(); ???????} ???} ???@Test ???public void test() { ???????Session session=sessionFactory.openSession(); ???????session.beginTransaction(); ???????????????Helloworld helloWorld=new Helloworld(); ???????helloWorld.setHelloWorld("Hello World！！！"); ???????//完全以操作对象的形式保存对象为表的一条记录 ???????session.save(helloWorld); ???????????????session.getTransaction().commit(); ???????session.close(); ???????????????????}}执行的时候的部分log
生成的表结构
插入的表数据
下面在来看用注解的方式的实现
注解的方式就不再需要Helloworld.hbm.xml文件
实体类修改如下
package com.fuwh.model;import javax.persistence.Column;import javax.persistence.Entity;import javax.persistence.GeneratedValue;import javax.persistence.Id;import javax.persistence.Table;import org.hibernate.annotations.GenericGenerator;//这是一个实体类@Entity@Table(name="t_helloworld")public class Helloworld { ???????private long id; ???private String helloWorld; ???????@Id ???@GeneratedValue(generator="_native") ???@GenericGenerator(name="_native",strategy="native") ???public long getId() { ???????return id; ???} ???public void setId(long id) { ???????this.id = id; ???} ???@Column(name="helloworld") ???public String getHelloWorld() { ???????return helloWorld; ???} ???public void setHelloWorld(String helloWorld) { ???????this.helloWorld = helloWorld; ???} ???????}另外在hibernate.cfg.xml中不再是引入Helloworld.hbm.xml资源文件，而是引入一个实体类
<?xml version=‘1.0‘ encoding=‘utf-8‘?><!DOCTYPE hibernate-configuration PUBLIC"-//Hibernate/Hibernate Configuration DTD//EN""http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd"> <hibernate-configuration> ???????<session-factory> ???????<!-- 数据库连接设置 --> ???????<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property> ???????<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/hibernate</property> ???????<property name="hibernate.connection.username">root</property> ???????<property name="hibernate.connection.password">mysqladmin</property> ???????<!-- ????????????指定方言，表明用的是哪种数据库，也可以不指定，hibernate默认会翻译成正确的数据库脚本 ???????????方言可以在 hibernate-release-xx.xx/project/etc/hibernate.properties 中查找 ????????--> ???????<property name="hibernate.dialect">MySQL5</property> ???????<!-- 设定时候更新表结构，不存在或自动创建 --> ???????<property name="hibernate.hbm2ddl.auto">update</property> ???????<!-- 配置 在后台打印出sql语句 --> ???????<property name="show_sql">true</property> ??????<!-- 引入实体类和表的映射文件 --> ???????<mapping class="com.fuwh.model.Helloworld"/> ???</session-factory> ???</hibernate-configuration>
执行结果也是一样的。
hibernate--HelloWorld
原文地址：http://www.cnblogs.com/wangsicongde/p/7573517.html