day_02使用注解的方式进行操作hibernate定义实体

星期二, 十二月 29, 2015 21:20:00

 

 

使用注解的方式进行操作hibernate定义实体

 

步骤:

1.引入hibernate-annotations.jar

   "hibernate-commons-annotations.jar"

   "ejb3-persistence.jar" 

2.建一个Teacher类

3.在数据库中建teacher表

   create table teacher(id int primary key,name varchar(20),title varchar(20))；

4.在Teacher加入注解:@Entity   //主键@Id

 

/*1.实体类(使用annotation进行实现，告诉hibernate是实体类，

 * 不需要再建立Teacher.hbm.xml文件进行映射)

 * 2.hibernate.cfg.xml进行配置即可

 * 3.建立一个TeacherTest

*/

 

5.在hibernate.cfg.xml进行配置

 

 <mapping class="com.zhuhw.hibernate.Teacher"/>

 

6.建立TeacherTest类

 

//因为使用的annotation，所以Configuration要使用AnnotationConfiguration

Configuration cf = new AnnotationConfiguration();

 

运行即可

 

 

代码案例:

package com.zhuhw.hibernate;

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

/*1.实体类(使用annotation进行实现，告诉hibernate是实体类，
 * 不需要再建立Teacher.hbm.xml文件进行映射)
 * 2.hibernate.cfg.xml进行配置即可
 * 3.建立一个TeacherTest
*/
@Entity
public class Teacher {
		private int id;
		private String name;
		private String title;
		//主键
		@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;
		}
	
		
}

 

 

 

<?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://localhost/hibernate</property>
        <property name="connection.username">root</property>
        <property name="connection.password">root</property>

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

        <!-- SQL dialect -->
        <property name="dialect">org.hibernate.dialect.MySQLDialect</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>-->
		<!-- hibernate去哪里找这个配置文件 -->
        <mapping resource="com/zhuhw/hibernate/Student.hbm.xml"/>
        
        <mapping class="com.zhuhw.hibernate.Teacher"/>

    </session-factory>

</hibernate-configuration>

 

 

 

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

import com.zhuhw.hibernate.Student;
import com.zhuhw.hibernate.Teacher;


public class TeacherTest {
	public static void main(String[] args){
		Teacher t = new Teacher();
		t.setId(2);
		t.setName("yuzhou");
		t.setTitle("aaaa");
		
		//因为使用的annotation，所以Configuration要使用AnnotationConfiguration
		
		Configuration cf = new AnnotationConfiguration();
		SessionFactory sf = cf.configure().buildSessionFactory();
		Session session = sf.openSession();
		//在hibernate中执行操作要在一个事务里面
		session.beginTransaction();
		session.save(t);
		session.getTransaction().commit();
		session.close();
		sf.close();
		
	}
}

 

运行结果:

Hibernate: insert into Teacher (name, title, id) values (?, ?, ?)

 

 

总结:

1.请务必建立自己动手查一手文档的能力

2.重要的是

     1.要建立了自己动手查一手文档的信心

     2.还有建立自己动手查一手文档的习惯

     3.主动学习，放弃被动接受灌输的习惯

 

 

星期二, 十二月 29, 2015   22:10:48