JPA-7 整合Spring

　　Spring整合JPA的具体实现代码下载地址：http://download.csdn.net/download/bingbeichen/9808227。

1. 具体实现

　　①. 新建java工程，并在工程目录下新建lib目录

　　②. 加入Spring、Hibernate、JPA、C3P0和MySQL数据库驱动所依赖的jar包
　　　添加Spring所依赖的jar包到lib目录中；
　　　添加hibernate-release-4.2.4.Final\lib\required*.jar到lib目录中；
　　　添加hibernate-release-4.2.4.Final\lib\jpa*.jar到lib目录中；
　　　添加hibernate-release-4.2.4.Final\lib\optional\c3p0*.jar到lib目录中；
　　　添加mysql-connector-java-5.1.7\mysql-connector-java-5.1.7-bin.jar到lib目录中。
　　　

　　③. 创建Spring的Bean配置文件，并做如下配置

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xmlns:context="http://www.springframework.org/schema/context"xmlns:tx="http://www.springframework.org/schema/tx"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsdhttp://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd"><!-- 配置自动扫描的包 --><context:component-scan base-package="com.qiaobc.jpa"></context:component-scan><!-- 配置C3P0数据源 --><context:property-placeholder location="classpath:db.properties"/><bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"><!-- 配置连接数据库的基本属性 --><property name="user" value="${jdbc.user}"></property><property name="password" value="${jdbc.password}"></property><property name="driverClass" value="${jdbc.driverClass}"></property><property name="jdbcUrl" value="${jdbc.jdbcUrl}"></property><!-- 配置其他属性 --></bean><!-- 整合目标一：配置EntityManagerFactory --><bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean"><property name="dataSource" ref="dataSource"></property><!-- 配置JPA提供商的适配器  通过内部bean的方式来配置 --><property name="jpaVendorAdapter"><bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"></bean></property><!-- 配置实体类所在的包 --><property name="packagesToScan" value="com.qiaobc.jpa.spring.entities"></property><!-- 配置JPA的基本属性：如JPA实现产品的基本属性 --><property name="jpaProperties"><props><prop key="hibernate.show_sql">true</prop><prop key="hibernate.format_sql">true</prop><prop key="hibernate.hbm2ddl.auto">update</prop></props></property></bean><!-- 整合目标二：配置JPA使用的事务管理器 --><bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager"><property name="entityManagerFactory" ref="entityManagerFactory"></property></bean><!-- 配置支持注解的事务配置 --><tx:annotation-driven transaction-manager="transactionManager"/></beans>

　　④. 创建实体类

package com.qiaobc.jpa.spring.entities;import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;@Table(name="JPA_PERSONS")
@Entity
public class Person {private Integer id;private String name;private String email;private Integer age;@Column(name="ID")@GeneratedValue@Idpublic Integer getId() {return id;}public void setId(Integer id) {this.id = id;}@Column(name="LAST_NAME")public String getName() {return name;}public void setName(String name) {this.name = name;}@Column(name="EMAIL")public String getEmail() {return email;}public void setEmail(String email) {this.email = email;}@Column(name="AGE")public Integer getAge() {return age;}public void setAge(Integer age) {this.age = age;}public Person(Integer id, String name, String email, Integer age) {super();this.id = id;this.name = name;this.email = email;this.age = age;}public Person() {super();}@Overridepublic String toString() {return "Person [id=" + id + ", name=" + name + ", email=" + email+ ", age=" + age + "]";}}

　　⑤. 创建PersonDao和PersonService，并在Spring配置文件中配置自动扫描的包

package com.qiaobc.jpa.dao;import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;import org.springframework.stereotype.Repository;import com.qiaobc.jpa.spring.entities.Person;@Repository
public class PersonDao {// 如何获取到和当前事务关联的EntityManager对象呢？// 通过@PersistenceContext注解来标记EntityManager成员变量@PersistenceContextprivate EntityManager entityManager;public void save(Person person) {entityManager.persist(person);}}

package com.qiaobc.jpa.service;import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;import com.qiaobc.jpa.dao.PersonDao;
import com.qiaobc.jpa.spring.entities.Person;@Service
public class PersonService {@Autowiredprivate PersonDao personDao;@Transactionalpublic void savePersons(Person person1, Person person2) {personDao.save(person1);
//      int result = 10 / 0;personDao.save(person2);}}

　　⑥. 测试环境配置是否成功

package com.qiaobc.jpa.spring;import javax.sql.DataSource;import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;import com.qiaobc.jpa.service.PersonService;
import com.qiaobc.jpa.spring.entities.Person;public class JPASpringTest {private ApplicationContext ctx = null;private PersonService personService = null;{ctx = new ClassPathXmlApplicationContext("applicationContext.xml");personService = ctx.getBean(PersonService.class);}@Testpublic void testDataSource() throws Exception {DataSource dataSource = (DataSource) ctx.getBean("dataSource");// 验证数据源是否配置成功，配置成功会输出如下代理对象// com.mchange.v2.c3p0.impl.NewProxyConnection@1103e5d9System.out.println(dataSource.getConnection());}@Testpublic void testPersonService() {Person person1 = new Person(null, "qiaobc", "qiaobc@163.com", 23);Person person2 = new Person(null, "qiaobb", "qiaobb@163.com", 23);// 验证EntityManager是否使用上Spring的声明式事务，若使用则输出代理对象// com.qiaobc.jpa.service.PersonService$$EnhancerByCGLIB$$8c049a52System.out.println(personService.getClass().getName());personService.savePersons(person1, person2);}}

2. 附录

<!-- 配置JPA提供者的适配器 -->
<bean id="jpaVendorAdapter"class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"><property name="databasePlatform"><bean class="com.atguigu.ssps.modules.persistence.Hibernates"factory-method="getDialect"><constructor-arg ref="dataSource"></constructor-arg></bean></property>
</bean>

<!-- 配置JPA的 EntityManager -->
<bean id="entityManagerFactory"class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean"><property name="dataSource" ref="dataSource"></property><property name="jpaVendorAdapter" ref="jpaVendorAdapter"></property><property name="packagesToScan" value="com.atuigu.crm"></property><property name="jpaProperties"><props><!-- 二级缓存相关 --><prop key="hibernate.cache.region.factory_class">org.hibernate.cache.ehcache.EhCacheRegionFactory</prop><prop key="net.sf.ehcache.configurationResourceName">ehcache-hibernate.xml</prop><!-- 生成的数据表的列的映射策略 --><prop key="hibernate.ejb.naming_strategy">org.hibernate.cfg.ImprovedNamingStrategy</prop><!-- hibernate 基本属性 --><prop key="hibernate.show_sql">true</prop><prop key="hibernate.format_sql">true</prop><prop key="hibernate.hbm2ddl.auto">update</prop></props></property>
</bean>