8.0注解方式代替映射文件

Posted 2020-09-09 chxbar.cn

1.Book类

 

package cn.siggy.pojo;

import java.util.Date;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;
//entity表示需要持久化的实体类
@Entity
//实体类 所对应的表
@Table(name="t_book")
public class Book {
	//id主键
	@Id
	//指定 主键生成策略
	@GeneratedValue(strategy=GenerationType.AUTO)
	private int id;
	private String name;
	private double price;
	private String author;
	private Date pubDate;
	/*get/set*/
}

　　

2.hibernate.cfg.xml【注解方式不需要Book.hbm.xml映射文件，但需要在*.cfg.xml中引入：<mapping class="cn.siggy.pojo.Book" />】

<!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>
	<!--数据库信息  -->
	<property name="connection.driver_class">
		com.mysql.jdbc.Driver
	</property>
	<property name="connection.url">jdbc:mysql:///hibernate4</property>
	<property name="connection.username">root</property>
	<property name="connection.password">root</property>
	<!--hibernate可选项 -->
	<property name="dialect">
		org.hibernate.dialect.MySQLDialect
	</property>
	<property name="show_sql">true</property>
	<property name="format_sql">true</property>
	<property name="hbm2ddl.auto">update</property>
	<!-- hbm文件 -->
	<mapping class="cn.siggy.pojo.Book" />
</session-factory>
</hibernate-configuration>

　　

3.测试代码

package cn.siggy.test;

import java.util.Date;

import org.hibernate.Session;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.hibernate.tool.hbm2ddl.SchemaExport;
import org.junit.Test;

import cn.siggy.pojo.Book;
import cn.siggy.util.HibernateUtil;

public class HibernateTest {
	@Test
	public void testCreateDB(){
		//3.x
		//Configuration cfg = new AnnotationConfiguration().configure();
		Configuration cfg = new Configuration().configure();
		SchemaExport se = new SchemaExport(cfg);
		se.create(true, true);
	}
	@Test
	public void testSave(){
		Session session = HibernateUtil.getSession();
		Book book = new Book();
		book.setName("丰乳肥臀");
		book.setPrice(60.5);
		book.setAuthor("莫言");
		book.setPubDate(new Date());
		Transaction tx = session.beginTransaction();
		session.save(book);
		tx.commit();
		HibernateUtil.closeSession();
	}
}

　　

4.测试结果