Hibernate4使用Annotation连接访问MySQL的小例子

1、创建一个Teacher类

package com.model;import javax.persistence.Entity;import javax.persistence.Id;@Entitypublic class Teacher {private int id;private String name;private String title;@Idpublic int getId() {return id;}public void setId(int id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public String getTitle() {return title;}public void setTitle(String title) {this.title = title;}}

--------Teacher类中使用Annotation

2、设置表结构，创建数据库和数据表

create database hibernate;use hibernate;create table teacher(id int primary key,name varchar(20),title varchar(20));

3、设置Hibernate配置文件hibernate.cfg.xml，其位置位于src下

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE hibernate-configuration PUBLIC"-//Hibernate/Hibernate Configuration DTD 3.0//EN""http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd"><hibernate-configuration><session-factory><!-- 连接的数据库驱动 --><property name="connection.driver_class">com.mysql.jdbc.Driver</property><!-- 连接的数据库的url --><property name="connection.url">jdbc:mysql://localhost:3306/hibernate</property><!-- 连接的数据库的用户名--><property name="connection.username">root</property><!-- 连接的数据库的密码 --><property name="connection.password"></property><!-- 配置Hibernate数据库方言 --><property name="Dialect">org.hibernate.dialect.MySQLDialect</property><!-- 输出执行的SQL语句 -->        <property name="show_sql">true</property><!-- 启动时撤销并重新创建数据库的模式 --><property name="hbm2ddl.auto">update</property><mapping class="com.model.Teacher"/></session-factory></hibernate-configuration>

4、建立测试类，测试

package com.test;import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.Transaction;import org.hibernate.cfg.Configuration;import org.hibernate.service.ServiceRegistry;import org.hibernate.service.ServiceRegistryBuilder;import com.model.Teacher;public class TeacherTest  {public static void main(String[] args) {Teacher teacher = new Teacher();teacher.setId(2);teacher.setName("黎明");teacher.setTitle("教授");Configuration cfg = new Configuration();cfg.configure();ServiceRegistry  sr = new ServiceRegistryBuilder().applySettings(cfg.getProperties()).buildServiceRegistry(); SessionFactory  sf = cfg.buildSessionFactory(sr);Session s = sf.openSession();Transaction tx = s.beginTransaction();s.save(teacher);tx.commit();s.close();sf.close();}}

5、运行测试类，并查看表中是否已添加一条数据记录，且后台输出执行的SQL语句：Hibernate: insert into Teacher (name, title, id) values (?, ?, ?)。

注意：项目建立时需将Hibernate的jar包（位于hibernate-release-4.1.2.Final\lib\required下的所有包）和MySQL的JDBC的包导入到项目中去；

cfg.configure()默认配置文件为hibernate.cfg.xml，即cfg.configure()等价于cfg.configure("hibernate.cfg.xml")，若配置文件不是这个名则必须指定配置文件名。

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其中，org.hibernate.cfg.AnnotationConfiguration已经弃用，直接使用org.hibernate.cfg.Configuration即可，创建语句Configuration cfg = new Configuration()而不是AnnotationConfiguration cfg = new AnnotationConfiguration()。