Hibernate-学习札记01

Hibernate-学习笔记01

第一个Hibernate小程序

 

    Hibernate配置文件：

<?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">com.mysql.jdbc.Driver</property>
        <property name="connection.url">jdbc:mysql://127.0.0.1:3306/hibernate</property>
        <property name="connection.username">root</property>
        <property name="connection.password">123</property>

        <!-- JDBC connection pool (use the built-in) --><!-- 很少使用hibernate自带的连接池 -->
        <!--<property name="connection.pool_size">1</property>-->

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

        <!-- Enable Hibernate's automatic session context management 使用SessionFactory.getCurrentSession()方法时使用 -->
        <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>
		<property name="format_sql">true</property>
		
        <!-- Drop and re-create the database schema on startup -->
        <!-- hbm:hibernate mapping To ddl:datebase definition language-->
        <property name="hbm2ddl.auto">update</property> 
        
		<!-- 注册：告诉hibernate Model文件在哪 -->
        <mapping resource="com/ibm/hibernate/model/Student.hbm.xml"/>
        <!-- 配饰AnnotationConfiguration时使用的 -->
		<!-- <mapping class="com.ibm.hibernate.model.Teacher"/> -->
    </session-factory>

</hibernate-configuration>

 

    模型类：

package com.ibm.hibernate.model;

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;
	}
	@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + id;
		return result;
	}
	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (getClass() != obj.getClass())
			return false;
		Student other = (Student) obj;
		if (id != other.id)
			return false;
		return true;
	}
	
	@Override
	public String toString() {
		
		return "id:"+id+"\tname:"+name+"\tage:"+age;
	}
}

 

  模型类配置文件：

<?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.ibm.hibernate.model">
	<class name="Student" table="STUDENT">
		<id name="id" column="ID"></id>
		<property name="name" column="NAME"></property>
		<property name="age" column="AGE"></property>
	</class>
</hibernate-mapping>

 

   测试文件：

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

import com.ibm.hibernate.model.Student;


public class StudentTest {
	public static void main(String[] args) {
		Student s = new Student();
		s.setId(001);
		s.setName("Tom");
		s.setAge(10);
		
		Session session = null; 
		SessionFactory sf = null;
		Transaction t = null;
		//1、读取配置文件
		Configuration cfg = new Configuration();
		//2、通过SessionFactory  一个数据库对应一个SessionFactory
		sf = cfg.configure().buildSessionFactory();
		//3、创建session
		//此处的session并不是web中的session
		//session只有在用时，才建立concation,session还管理缓存。
		//session用完后，必须关闭。
		//session是非线程安全，一般是一个请求一个session.
		
		session = sf.openSession();
		//4、手动开启事务(可以在hibernate.cfg.xml配置文件中配置自动开启事务)
		t = session.beginTransaction();
		try {
			//5、保存数据，此处的数据是保存对象，这就是hibernate操作对象的好处
			//简单就一句话
			session.save(s);
			//6、事务成功提交/失败则回滚
			t.commit();
		} catch (HibernateException e) {
			t.rollback();
			e.printStackTrace();
		}
		//7、关闭session
		session.close();
		//8、关闭 sessionfactory
		sf.close();
	}
}

 

 

   结果显示：

 

 

    数据库字段和模型字段相同，省略。