Hibernate Struts2 整合配置全解

Hibernate 配置全解

Hibernate 的意思是“冬眠”
在Java中的作用和它本来的意思没有太大的关联。

在MVC开发模式中，Struts是视图层的框架，
Hibernate是帮助我们更容易地和数据库打交道的，是属于模型层的框架。

ORMapping的概念
Object：程序对象
Relationship：数据库表（关系型数据库）RDBMS
Mapping：映射
ORMapping，像操作对象一样，来操作数据库

举例：
Student student=new Student();
student.name="Mike";
student.age="20";
session.save(student);

其他的ORMapping框架：TopLink,JDO

数据库其他框架:mybatis
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讲课思路和环境搭建

Hibernate 2,3,4，版本差异比较大

学习方法介绍，项目中学习，学生选课管理系统

搭建struts2和hibernate开发环境

struts 2.3.20
hibernate 4.3.8 Final

hibernate官网 http://hibernate.org/ org = 组织 = orgnization
1.添加hibernate的jar包 lib/required
2.添加struts2的jar包     apps/解压一个项目blank/lib
3.添加mysql数据库连接驱动
4.添加struts2的配置文件struts.xml
5.添加hibernate的配置文件hibernate.cfg.xml

<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="connection.url">jdbc:mysql://localhost:3306/curricula</property> 

<property name="connection.username">root</property> 

<property name="connection.password">12345678</property>  

<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
<property name="show_sql">true</property> //自动创建数据库
 hbm2ddl.auto 是否自动创建数据库

6.编写初始化SessionFactory和获取Session的代码。
  SessionFactory：连接池（很多连接）  根据  Hibernate  获取数据库
  Session：连接
public class HibernateUtil {  //连接测试
private static SessionFactory sessionFactory;
private static SessionFactory buildSessionFactory() {
try {
Configuration configuration = new Configuration();
configuration.configure("hibernate.cfg.xml");
ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder()
.applySettings(configuration.getProperties()).build();
SessionFactory sessionFactory = configuration
.buildSessionFactory(serviceRegistry);
return sessionFactory;
} catch (Throwable ex) {
throw new ExceptionInInitializerError(ex);
}
}
public static SessionFactory getSessionFactory() {
if (sessionFactory == null)
sessionFactory = buildSessionFactory();
return sessionFactory;
}
public static Session openSession() {
return getSessionFactory().openSession();
}
}

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HibernateUtil.javapackage common;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;

public class HibernateUtil {

private static SessionFactory sessionFactory;

private static SessionFactory buildSessionFactory() {
try {
Co
97d2
nfiguration configuration = new Configuration();
configuration.configure("hibernate.cfg.xml");

ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder()
.applySettings(configuration.getProperties()).build();

SessionFactory sessionFactory = configuration
.buildSessionFactory(serviceRegistry);

return sessionFactory;
} catch (Throwable ex) {
throw new ExceptionInInitializerError(ex);
}
}

public static SessionFactory getSessionFactory() {
if (sessionFactory == null)
sessionFactory = buildSessionFactory();
return sessionFactory;
}

public static Session openSession() {
return getSessionFactory().openSession();
}

}
Student.javapackage model;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;

@Entity
public class Student {
private int id;
private String name;
private String pwd;
private String phone;
private String grade;
private String photo;
@Id
@GeneratedValue
public 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 getPwd() {
return pwd;
}
public void setPwd(String pwd) {
this.pwd = pwd;
}
public String getPhone() {
return phone;
}
public void setPhone(String phone) {
this.phone = phone;
}
public String getGrade() {
return grade;
}
public void setGrade(String grade) {
this.grade = grade;
}
public String getPhoto() {
return photo;
}
public void setPhoto(String photo) {
this.photo = photo;
}

}
Student.hbm.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="model">
<class name="Student" table="student">
<id name="id" column="id">
<generator class="native"/>
</id>
<property name="name"></property>
<property name="pwd" column="pwd" type="string" length="50"></property>
<property name="phone" length="50"></property>
<property name="photo" length="150"></property>
</class>
</hibernate-mapping>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>
<!-- Database connection settings -->
<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="connection.url">jdbc:mysql://localhost:3306/curricula</property>

<property name="connection.username">root</property>

<property name="connection.password">12345678</property>

<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
<property name="show_sql">true</property>

<!-- Drop and re-create the database schema on startup -->
<property name="hbm2ddl.auto">update</property>
<mapping class="model.Student"/>
</session-factory>
</hibernate-configuration>struts.xml<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
"http://struts.apache.org/dtds/struts-2.3.dtd">

<struts>
<constant name="struts.devMode" value="true" />
</struts>

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