Hibernate-学习笔记02-Annotation

使用Annotation：

 1、引入jar包

       (1)hibernate-annotations.jar

       (2)hibernate-commons-annotations.jar

       (3)ejb3-persistence.jar

2、数据库建立，省略

3、配置文件

     对比：

<!-- 传统 --> 
<mapping resource="com/ibm/hibernate/model/Student.hbm.xml"/>
<!--  Annotation --> 
<mapping class="com.ibm.hibernate.model.Teacher"/>

代码实现：

实体类

package com.ibm.hibernate.model;

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

//Entity 为Annotation 中的注解，表明该类为实体类
@Entity
public class Teacher {
	private int id;
	private String name;
	private String title;
	
	//标明实体类中的Primary Key
	@Id
	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 getTitle() {
		return title;
	}
	public void setTitle(String title) {
		this.title = title;
	}
	
}

 Hibernate.cfg.xml

<?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>

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

         !-- 注册：告诉hibernate Model文件在哪 ,区别于传统resource=""-->
		<mapping class="com.ibm.hibernate.model.Teacher"/>
    </session-factory>

</hibernate-configuration>

测试代码：

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

import com.ibm.hibernate.model.Student;
import com.ibm.hibernate.model.Teacher;


public class TeacherTest {
	public static void main(String[] args) {
		
		Teacher tea = new Teacher();
		tea.setId(002);
		tea.setName("Jude");
		tea.setTitle("1");
		
		Session session = null; 
		SessionFactory sf = null;
		Transaction t = null;
		//1、区别与传统的配置文件，Configuration实例化的是一个AnnotationConfiguration
		//传统的配饰文件，Configuration实例化的是一个Configuration
		Configuration cfg = new AnnotationConfiguration();		
		sf = cfg.configure().buildSessionFactory();
		session = sf.openSession();
		t = session.beginTransaction();
		try {
			session.save(tea);
			t.commit();
		} catch (HibernateException e) {
			t.rollback();
			e.printStackTrace();
		}
		session.close();
		sf.close();
	}
}