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2聲明式管理Hibernate本地事務(wù)

Spring提供了一種統(tǒng)一的IoC方式來(lái)管理Hibernate事務(wù)（本地或者分布式事務(wù)）。從Spring接手hibernate.cfg.xml（Hibernate的基本配置文件）起，Hibernate事務(wù)便輕易交由Spring拖管了。

說(shuō)明：在上一章介紹IBatis和DAO的時(shí)候，曾經(jīng)針對(duì)事務(wù)和DAO的關(guān)系簡(jiǎn)單的進(jìn)行了探討。通常DAO的粒度應(yīng)該都是比較細(xì)的，即它們只是一些單步的CRUD操作，所以就需要引入一個(gè)業(yè)務(wù)對(duì)象來(lái)包裹DAO，這樣，就可以在業(yè)務(wù)對(duì)象的基礎(chǔ)上，提供更粗粒度的事務(wù)劃分了（比如跨越多個(gè)DAO的方法調(diào)用進(jìn)行事務(wù)管理）。

為了能對(duì)DAO進(jìn)行更粗粒度的事務(wù)控制，需要為其增加一個(gè)業(yè)務(wù)對(duì)象。下面給出了該業(yè)務(wù)對(duì)象的接口和實(shí)現(xiàn)，如代碼10.25~10.26所示。

package chapter10.spring.hibernate;

import chapter10.hibernate.domain.Category;

public interface StockFacade {

public void business1(Category category);

public void someOtherBusiness();

}

public class BusinessFacadeImpl implements StockFacade {

private StockDao stockDao;

public void setStockDao(StockDao stockDao) {

??? this.stockDao = stockDao;

}

public void business1(Category category) {

??? stockDao.createCategoryCascade(category);

??? stockDao.retrieveProductBy(category);

??? stockDao.deleteCategoryCascade(category);

}

public void someOtherBusiness() {

??? //other implemention

}

}

接著給出關(guān)于事務(wù)策略的配置，其中使用了Spring針對(duì)Hibernate3給出的HibernateTransactionManager，它提供了Hibernate的本地事務(wù)管理策略，如代碼10.27所示。

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN"

"http://www.springframework.org/dtd/spring-beans.dtd">

<beans>

<bean id="transactionManager"

class="org.springframework.orm.hibernate3.HibernateTransactionManager">①

??? <property name="sessionFactory" >

????? <ref bean="sessionFactory" />

??? </property>

</bean>

<bean id="business"

class="chapter10.spring.hibernate.BusinessFacadeImpl">

??? <property name="stockDao">

????? <ref bean="stockDao"/>

??? </property>

</bean>

<bean id="businessProxy"

??? class="org.springframework.transaction.interceptor.TransactionProxyFactoryBean">

??? <property name="transactionManager">

????? <ref bean="transactionManager" />

??? </property>

??? <property name="target">

??? ?? <ref bean="business" />

??? </property>

??? <property name="transactionAttributes">

????? <props>

??????? <!--運(yùn)行在當(dāng)前事務(wù)范圍內(nèi)，如果當(dāng)前沒(méi)有啟動(dòng)事務(wù)，那么創(chuàng)建一個(gè)新的事務(wù)-->

??????? <prop key="business*">PROPAGATION_REQUIRED</prop>

??????? <!--運(yùn)行在當(dāng)前事務(wù)范圍內(nèi)，如果當(dāng)前沒(méi)有啟動(dòng)事務(wù)，那么拋出異常-->

??? ???? <prop key="someOtherBusiness*">PROPAGATION_MANDATORY</prop>

????? </props>

??? </property>

</bean>

</beans>

package chapter10.spring.hibernate;

import org.springframework.context.ApplicationContext;

import org.springframework.context.support.ClassPathXmlApplicationContext;

import chapter10.hibernate.domain.Category;

import junit.framework.TestCase;

public class HibernateTransactionUsageTest extends TestCase {

private StockFacade stockBusiness;

protected void setUp() throws Exception {

??? String path = "ch10/spring/hibernate/";

??? ApplicationContext ctx = new ClassPathXmlApplicationContext(

???????? new String[]{path+"dataAccessContext-support-local.xml",

???????????? path+"transaction-context.xml"});

??? stockBusiness = (StockFacade)ctx.getBean("businessProxy");

}

public void testTransctionUsage() {

??? Category category = new Category("RABBIT");

??? category.setName("Rabbit");

??? category.setDescn("Desciption of Rabbit");

??? stockBusiness.business1(category);

}

}