Spring整合JPA

导入jar包

配置配置文件

db.properties

jdbc.user=root
jdbc.password=root
jdbc.driverClass=com.mysql.jdbc.Driver
jdbc.jdbcUrl=jdbc:mysql:///jpa

applicationContext.xml

<?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.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd
        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd">

    <!-- 配置自动扫描的包 -->
    <context:component-scan base-package="com.xiaoming.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">
        <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>   
    </bean>

    <!-- 配置其他属性 -->

    <!-- 配置 EntityManagerFactory -->
    <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <!-- 配置 JPA 提供商的适配器. 可以通过内部 bean 的方式来配置 -->
        <property name="jpaVendorAdapter">
            <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"/>
        </property>
        <!-- 配置实体类所在的包 -->
        <property name="packagesToScan" value="com.xiaoming.jpa.entities"></property>
        <!-- 配置 JPA 的基本属性. 例如 JPA 实现产品的属性 -->
        <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>

    <!-- 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>

    <!-- 配置支持基于注解是事务配置 -->
    <tx:annotation-driven transaction-manager="transactionManager"/>

</beans>

Dao层需要注意的地方

    //如何获取到和当前事务关联的EntityManager对象?
    //通过 @PersistenceContext注解来获取

    @PersistenceContext
    private EntityManager entityManager;

    public void save(Person person){
        entityManager.persist(person);
    }

测试代码

    @Test
    public void testPersonService(){
        Person p1 = new Person();
        p1.setUsername("张三");
        p1.setPassword("123");
        p1.setAge(11);

        Person p2 = new Person();
        p2.setUsername("李四");
        p2.setPassword("123");
        p2.setAge(12);

        System.out.println(personService.getClass().getName());
        personService.save(p1, p2);
    }