SSH_DEMO applicationContext.xml中使用JPA连接数据库

1. 首先定义persistence.xml文件

<?xml version="1.0"?>
<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 http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd" version="1.0">
  <persistence-unit name="demo" transaction-type="RESOURCE_LOCAL">
  	<provider>org.hibernate.ejb.HibernatePersistence</provider>
	<properties>
         <property name="hibernate.dialect" value="org.hibernate.dialect.MySQL5Dialect"/>
         <property name="hibernate.connection.driver_class" value="com.mysql.jdbc.Driver"/>
         <property name="hibernate.connection.username" value="root"/>
         <property name="hibernate.connection.password" value="root"/>
         <property name="hibernate.connection.url" value="jdbc:mysql://localhost:3306/demo?useUnicode=true&amp;characterEncoding=UTF-8"/>
         <property name="hibernate.max_fetch_depth" value="3"/>
         <property name="hibernate.hbm2ddl.auto" value="update"/>
	     <property name="hibernate.jdbc.fetch_size" value="18"/>
	     <property name="hibernate.jdbc.batch_size" value="10"/>
	     <property name="hibernate.show_sql" value="true"/>
	     <property name="hibernate.format_sql" value="true"/> 
      </properties>
  </persistence-unit>
</persistence>

2. 在applicationContext.xml中配置

<bean id="entityManagerFactory"
		class="org.springframework.orm.jpa.LocalEntityManagerFactoryBean">
		<property name="persistenceUnitName" value="demo"></property>
	</bean>
    
    <!-- 配置事务管理器 -->

	<bean id="txManager" class="org.springframework.orm.jpa.JpaTransactionManager">
		<property name="entityManagerFactory" ref="entityManagerFactory"></property>
	</bean>

    <!-- 配置声明式事务：方法一，在Service实现类或者public实现方法上使用注解@Transactional，则此类或方法就会启用事务机制 -->
    <tx:annotation-driven transaction-manager="txManager"/>