Hibernate基础教程
Hibernate第一餐
1、在eclipse中安装JBoss Tools插件
2、导入相应的包
- lib\required文件夹下的包
- log4j.jar
- 数据库驱动
3、创建hibernate的配置文件
在src目录下创建hibernate.cfg.xml文件，在这个文件中完成数据库基本信息的配置，这些配置信息可以在project\etc下的hibernate.properties文件中找到（可以拷贝project\etc目录下的同名文件进行修改）
hibernate.cfg.xml
<!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>
<!-- 配置数据库方言，用来确定要连接的数据库 -->
<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
<!-- 配置数据库驱动 -->
<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
<!-- 配置数据库连接地址 -->
<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf-8</property>
<!-- 配置数据库连接用户名 -->
<property name="hibernate.connection.username">root</property>
<!-- 配置数据库连接密码 -->
<property name="hibernate.connection.password">123</property>
<!-- 自动显示相应的SQL语句 -->
<property name="show_sql">true</property>
<!-- 第一次加载hibernate时根据model类会自动建立起表的结构（前提是先建立好数据库），以后加载hibernate时根据 model类自动更新表结构 -->
<!-- hbm2ddl:hibernate mapping to database define language -->
<property name="hibernate.hbm2ddl.auto">update</property>
<!-- 加入实体类的映射文件 -->
<mapping resource="cap/model/User.hbm.xml"/>
</session-factory>
</hibernate-configuration>4、创建实体类
User.java
package cap.model;
import java.util.Date;
public class User {
private int id;
private String userName;
private String password;
private Date birthday;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public Date getBirthday() {
return birthday;
}
public void setBirthday(Date birthday) {
this.birthday = birthday;
}
@Override
public String toString() {
return "id=" + id + ", userName=" + userName + ", password="
+ password + ", birthday=" + birthday;
}
}5、在实体类所在的包中创建相应的hbm文件
hbm文件用来指定实体类和数据库表的映射关系，可以在project文件夹下搜索“hbm”，然后随便拷贝一个hbm文件进行修改，例如：Account.hbm.xml
User.hbm.xml
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="cap.model">
<class name="User" table="t_user">
<id name="id">
<generator class="native" /> <!-- 自动递增，Oracle中使用“sequence”，MySQL中使用“increment”，“native”同时兼容Oracle和MySQL -->
</id>
<property name="userName" type="string"/>
<property name="password"/>
<property name="birthday"/>
</class>
</hibernate-mapping>6、将hbm文件加载到hibernate.cfg.xml文件中
7、测试
Test.java
package cap.test;
import java.util.Date;
import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;
import cap.model.User;
public class Test {
@org.junit.Test
public void test01() {
//创建SessionFactory(SessionFactory是线程安全的)
Configuration cfg = new Configuration().configure(); //创建Configuration对象
ServiceRegistry serviceRegistry = new ServiceRegistryBuilder()
.applySettings(cfg.getProperties()).buildServiceRegistry();
SessionFactory factory=cfg.buildSessionFactory(serviceRegistry);
//创建Session
Session session=null;
try {
session=factory.openSession();
//通过Session进行数据库操作
session.beginTransaction(); //开启事务
User user=new User();
user.setUserName("土豪");
user.setPassword("123456");
user.setBirthday(new Date());
session.save(user);
session.getTransaction().commit(); //提交事务
} catch (HibernateException e) {
e.printStackTrace();
if(session!=null) session.getTransaction().rollback(); //事务回滚
} finally {
if(session!=null) session.close();
}
}
}8、结果
自动在数据库中创建t_user表并插入数据
在控制台输出相应的SQL语句
注意：在实际开发中，不会用hibernate自动生成数据库表，而是通过PD设计
Hibernate实现简单的CRUD
HibernateUtil.java
package cap.util;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;
public class HibernateUtil {
private static final SessionFactory FACTORY=bulidSessionFactory();
private static SessionFactory bulidSessionFactory() {
Configuration cfg = new Configuration().configure();
ServiceRegistry serviceRegistry = new ServiceRegistryBuilder()
.applySettings(cfg.getProperties()).buildServiceRegistry();
return cfg.buildSessionFactory(serviceRegistry);
}
public static SessionFactory getFactory() {
return FACTORY;
}
public static Session openSession() {
return FACTORY.openSession();
}
public static void close(Session session){
if(session!=null){
session.close();
}
}
}TestCRUD.java
package cap.test;
import java.util.Date;
import java.util.List;
import org.hibernate.Session;
import org.junit.Test;
import cap.model.User;
import cap.util.HibernateUtil;
public class TestCRUD {
/* * Hibernate的增(Create)删(Delete)改(Update)查(Retrieve) */
@Test
public void testAdd(){
Session session=null;
try {
session=HibernateUtil.openSession();
session.beginTransaction();
User user=new User();
user.setUserName("张洲铭");
user.setPassword("325436");
user.setBirthday(new Date());
session.save(user);
session.getTransaction().commit();
} catch (Exception e) {
e.printStackTrace();
if(session!=null) session.getTransaction().rollback();
} finally {
HibernateUtil.close(session);
}
}
@Test
public void testLoad(){
Session session=null;
try {
session=HibernateUtil.openSession();
User user=(User) session.load(User.class, 2);
System.out.println(user);
} catch (Exception e) {
e.printStackTrace();
} finally {
HibernateUtil.close(session);
}
}
@Test
public void testUpdate(){
Session session=null;
try {
session=HibernateUtil.openSession();
session.beginTransaction();
User user=(User) session.load(User.class, 2);
user.setUserName("胡杰");
session.update(user);
session.getTransaction().commit();
} catch (Exception e) {
e.printStackTrace();
if(session!=null) session.getTransaction().rollback();
} finally {
HibernateUtil.close(session);
}
}
@Test
public void testDelete(){
Session session=null;
try {
session=HibernateUtil.openSession();
session.beginTransaction();
User user=new User();
user.setId(2);
session.delete(user);
session.getTransaction().commit();
} catch (Exception e) {
e.printStackTrace();
if(session!=null) session.getTransaction().rollback();
} finally {
HibernateUtil.close(session);
}
}
@Test
public void testList(){
Session session=null;
try {
session=HibernateUtil.openSession();
@SuppressWarnings("unchecked")
List<User> users=session.createQuery("from User").list();
for(User user:users){
System.out.println(user);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
HibernateUtil.close(session);
}
}
@Test
public void testPager(){
Session session=null;
try {
session=HibernateUtil.openSession();
@SuppressWarnings("unchecked")
List<User> users=session.createQuery("from User").setFirstResult(0).setMaxResults(3).list();
for(User user:users){
System.out.println(user);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
HibernateUtil.close(session);
}
}
}