hibernate初探

1.新建java项目bibernate_001，引入jar包，本例使用的是hibernate-3.3.2，包括hibernate的jar包，slf4j包和jdbc包

其中hibernate的jar包包括核心包以及必须的jar包



2.在数据库创建表student

-- Create table
create table STUDENT
(
id   NUMBER not null,
name VARCHAR2(20),
age  NUMBER
)
tablespace USERS
pctfree 10
initrans 1
maxtrans 255
storage
(
initial 64
minextents 1
maxextents unlimited
);
-- Create/Recreate primary, unique and foreign key constraints
alter table STUDENT
add constraint PK primary key (ID)
using index
tablespace USERS
pctfree 10
initrans 2
maxtrans 255
storage
(
initial 64K
minextents 1
maxextents unlimited
);

3.创建hibernate配置文件hibernate.cfg.xml，位于src目录下

<?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>

<!-- Database connection settings -->
<property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property>
<property name="connection.url">jdbc:oracle:thin:@127.0.0.1:1521:orcl</property>
<property name="connection.username">scott</property>
<property name="connection.password">tiger</property>

<!-- JDBC connection pool (use the built-in) -->
<!-- <property name="connection.pool_size">1</property> -->

<!-- SQL dialect -->
<property name="dialect">org.hibernate.dialect.Oracle9Dialect</property>

<!-- Enable Hibernate's automatic session context management -->
<!--  <property name="current_session_context_class">thread</property> -->

<!-- Disable the second-level cache  -->
<property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>

<!-- Echo all executed SQL to stdout -->
<property name="show_sql">true</property>

<!-- Drop and re-create the database schema on startup -->
<property name="hbm2ddl.auto">update</property>

<mapping resource="com/baosight/model/Student.hbm.xml"/>

</session-factory>

</hibernate-configuration>

4.新建实体类Student

package com.baosight.model;

/**
* <p>Title: </p>
* <p>Description:Student </p>
* <p>Company: </p>
* @author yuan
* @date 2016-4-10 下午12:32:46*/
public class Student {
private int id;
private String name;
private int age;
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 int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}

}

5.新建实体类对数据库表的映射文件Student.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="com.baosight.model">
<class name="Student">
<id name="id" ></id>
<property name="name"></property>
<property name="age"></property>
</class>
</hibernate-mapping>

6.新建测试类TestStu对数据新增进行测试

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;

import com.baosight.model.Student;

/**
* <p>Title: </p>
* <p>Description:TestStu </p>
* <p>Company: </p>
* @author yuan
* @date 2016-4-10 下午3:16:01*/
public class TestStu {

/**
* @Title: main
* @Description: TODO
* @param args
* @return void
* @throws
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
//学生测试类
Student s = new Student();
s.setId(1);
s.setName("s1");
s.setAge(20);

//读取配置文件
Configuration cfg = new Configuration();
//得到session工厂
SessionFactory sf = cfg.configure().buildSessionFactory();
//得到session
Session session = sf.openSession();
//开启事务
session.beginTransaction();
//session执行save
session.save(s);
//事务提交
session.getTransaction().commit();
//关闭session
session.close();
//关闭session工厂
sf.close();
}

}

7.查询数据库，显示数据已经成功插入

查询结果：1 1
s1 20

以上即为一个最简单的使用hibernate进行插入操作的demo,hibernate最大的优点在于对操作数据库的封装，不用出现sql语句，相关配置均在实体类和数据库表的映射文件中，后面复杂的操作可能配置会相应的复杂，不过，hibernate提供了annotation，可以极大地简化这一过程。