以下是典型的persistence.xml---持久化单元

 <persistence xmlns="http://java.sun.com/xml/ns/persistence" version="1.0">
		<persistence-unit  name="spitterPU">
			<class>com.habuma.spitter.domain.Spitter</class>
			<class>com.habuma.spitter.domain.Spittle</class>
			<properties>
				<propertyname="toplink.jdbc.driver" value="org.hsqldb.jdbcDriver"/>
				<propertyname="toplink.jdbc.url" value= "jdbc:hsqldb:hsql://localhost/spitter/spitter"/>
				<propertyname="toplink.jdbc.user" value="sa" />
				<propertyname="toplink.jdbc.password" value="" />
			</properties>
		</persistence-unit>
	</persistence>

	<bean id="emf" class="org.springframework.orm.jpa.LocalEntityManagerFactoryBean">
		<propertyname="persistenceUnitName"value="spitterPU"/>
	</bean>

 <bean id="emf"class=
		"org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
		<propertyname="dataSource"ref="dataSource"/><!-- 引用数据源-->
		<propertyname="jpaVendorAdapter"ref="jpaVendorAdapter"/><!-- jpa提供商-->
	</bean>

 <bean id="jpaVendorAdapter"
		class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
		<propertyname="database"value="HSQL"/><!--指明那种数据库，下面提供了多种数据库类型-->
		<propertyname="showSql"value="true"/>
		<propertyname="generateDdl"value="false"/>
		<propertyname="databasePlatform" value="org.hibernate.dialect.HSQLDialect"/>
	</bean>

 IBM DB2 	DB2
		Apache Derby   DERBY
		H2 		H2
		Hypersonic	 HSQL
		INFORMIX 	INFORMIX
		MYSQL 	MYSQL
		Oracle 		ORACLE
		PostgresQL 	POSTGRESQL
		Microsoft SQL 	Server SQLSERVER
		Sybase 	SYBASE

 如果服务器中已经创建好了EntityManagerFactory,可以通过JNDI查找：
	<jee:jndi-lookupid="emf"jndi-name="persistence/spitterPU"/>

 编写基于JPA的DAO:

 Spring也对jpa集成提供了JpaTemplate模板，以及对应的dao支持JpaDaoSupport,但是为了提供更纯粹的JPA方式，基于模板的JPA已经弃用了。
 鉴于纯粹的JPA方式远胜于基于模板的JPA,所以本章重点关注如何构建不使用Spring的JPA DAO。

 import java.util.List;
	import javax.persistence.EntityManager;
	import javax.persistence.PersistenceContext;
	import org.springframework.dao.DataAccessException;
	import org.springframework.stereotype.Repository;
	import org.springframework.transaction.annotation.Transactional;
	import com.habuma.spitter.domain.Spitter;
	import com.habuma.spitter.domain.Spittle;
	
	@Repository("spitterDao")  //捕获异常
	@Transactional  //事物管理
	public classJpaSpitterDaoimplementsSpitterDao{
	
	private static final String RECENT_SPITTLES= "SELECTsFROMSpittles";
	private static final String ALL_SPITTERS= "SELECTsFROMSpitters";
	private static final String SPITTER_FOR_USERNAME= "SELECTsFROMSpittersWHEREs.username=:username";
	private static final String SPITTLES_BY_USERNAME= "SELECTsFROMSpittlesWHEREs.spitter.username=:username";
	
	@PersistenceContext //注入EntityManager em
	private EntityManager em;
	
	public voidaddSpitter(Spitter spitter){
		em.persist(spitter);
	}
	public SpittergetSpitterById(long id){
		returnem.find(Spitter.class,id);
	}
	public voidsaveSpitter(Spitter spitter){
		em.merge(spitter); //更新
	}
	...
	}

 <!-- 以下两个bean要装配到spring中去-->
	<bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor"/>

	<bean class="org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor"/>

Spring：Spring 中集成JPA；,布布扣,bubuko.com

Spring：Spring 中集成JPA；