JPA配置

JPA是ORM规范，hibernate、topLink、jda是ORM框架。JPA类似JDBC，将各个ORM产品规范法，便于移植。

1、引入JAR包

antlr.jar

commons-collections-3.1.jar

dom4j-1.6.1.jar

hibernate-entitymanager.jar

hibernate-jpa-2.0-api-1.0.0.Final.jar

hibernate3.jar

jboss-common.jar

jta-1.1.jar

slf4j-api-1.5.8.jar

slf4j-nop-1.5.8.jar

ojdbc6.jar

 

2、新建JPA配置文件，在src下新建文件夹META-INF，文件夹下新建persistence.xml配置文件，内容如下：

<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence" 
			 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  
			 xsi:schemaLocation="http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd" version="1.0">  

	<!--    
		Name属性用于定义持久化单元的名字 (name必选,空值也合法);   
		transaction-type 指定事务类型(可选)    
	--> 
	<persistence-unit name="oracleDB" transaction-type="RESOURCE_LOCAL">  
	   	<properties>  
		    <property name="hibernate.dialect" value="org.hibernate.dialect.OracleDialect" />  
		    <property name="hibernate.connection.driver_class" value="oracle.jdbc.driver.OracleDriver" />  
		    <property name="hibernate.connection.username" value="ky" />  
		    <property name="hibernate.connection.password" value="ky" />  
		    <property name="hibernate.connection.url" value="jdbc:oracle:thin:@(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=192.168.0.101)(PORT=1522))(ADDRESS=(PROTOCOL=TCP)(HOST=192.168.0.100)(PORT=1521))(LOAD_BALANCE=yes)(FAILOVER=on))(CONNECT_DATA=(SERVICE_NAME=orcl)))" />  
		    <property name="hibernate.max_fetch_depth" value="3" />  
		    <property name="hibernate.hbm2ddl.auto" value="validate"/>
		    <property name="hibernate.show_sql" value="true" />  
	   	</properties>
	</persistence-unit>
</persistence>

3、新建实体类

package com.yd4.struts2.entity;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;

/**
 * @author 作者：xiaoZhi
 * @version 创建时间：2013-12-6 下午03:23:36
 * @detail
 **/
@Entity
@Table(name = "td_xiaozhi_test")
public class Test {
	@Id
	private String zuhao;

	@Column
	private String user_name;

	public String getZuhao() {
		return zuhao;
	}

	public void setZuhao(String zuhao) {
		this.zuhao = zuhao;
	}

	public String getUser_name() {
		return user_name;
	}

	public void setUser_name(String user_name) {
		this.user_name = user_name;
	}

}

4、测试JPA配置是否成功

 

package com.yd4.struts2.test;

import java.util.List;

import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;
import javax.persistence.Query;

import com.yd4.struts2.entity.Test;


/**
 * @author  作者：xiaoZhi
 * @version 创建时间：2013-12-6 下午04:07:05
 * @detail  
 **/
public class Main {
	public static void main(String[] args) {
		EntityManagerFactory emf = Persistence.createEntityManagerFactory("oracleDB");
		EntityManager em = emf.createEntityManager();
		
		Query query = em.createQuery("from Test t");
		@SuppressWarnings("unchecked")
		List<Test> list = query.getResultList();
		
		em.close();
		emf.close();
		
		for (Test test : list) {
			System.out.println(test.getUser_name());
		}
	}
}

若上述成功，则配置JPA成功。