Spring 多数据源事务配置有关问题

2013-09-11

Spring 多数据源事务配置问题在SpringSide 3 中，白衣提供的预先配置好的环境非常有利于用户进行快速开发，

Spring 多数据源事务配置问题

在SpringSide 3 中，白衣提供的预先配置好的环境非常有利于用户进行快速开发，但是同时也会为扩展带来一些困难。最直接的例子就是关于在项目中使用多个数据源的问题，似乎很难搞。在上一篇中，我探讨了SpringSide 3 中的数据访问层，在这一篇中，我立志要解决多数据源配置的难题，我的思路是这样的：

第一步、测试能否配置多个DataSource
第二步、测试能否配置多个SessionFactory
第三步、测试能否配置多个TransactionManager
第四步、测试能否使用多个TransactionManager，也就是看能否配置多个<tx:annotation-driven/>

基本上到第四步就应该走不通了，因为Spring中似乎不能配置多个<tx:annotation-driven/>，而且@transactional注解也无法让用户选择具体使用哪个TransactionManager。也就是说，在SpringSide的应用中，不能让不同的数据源分别属于不同的事务管理器，多数据源只能使用分布式事务管理器，那么测试思路继续如下进行：

第五步、测试能否配置JTATransactionManager

如果到这一步，项目还能顺利在Tomcat中运行的话，我们就算大功告成了。但我总认为事情不会那么顺利，我总觉得JTATransactionManager需要应用服务器的支持，而且需要和JNDI配合使用，具体是不是这样，那只有等测试后才知道。如果被我不幸言中，那么进行下一步：

第六步、更换Tomcat为GlassFish，更换JDBC的DataSource为JNDI查找的DataSource，然后配置JTATransactionManager

下面测试开始，先假设场景，还是继续用上一篇中提到的简单的文章发布系统，假设该系统运行一段时间后非常火爆，单靠一台服务器已经无法支持巨大的用户数，这时候，站长想到了把数据进行水平划分，于是，需要建立一个索引数据库，该索引数据库需保存每一篇文章的Subject及其内容所在的Web服务器，而每一个Web服务器上运行的项目，需要同时访问索引数据库和内容数据库。所以，需要创建索引数据库，如下：
create database puretext_index;

use puretext_index;

create table articles(
id int primary key auto_increment,
subject varchar(256),
webserver varchar(30)
);

第一步测试，配置多个DataSource，配置文件如下：
application.properties：
jdbc.urlContent=jdbc:mysql://localhost:3306/PureText?useUnicode=true&characterEncoding=utf8
jdbc.urlIndex=jdbc:mysql://localhost:3306/PureText_Index?useUnicode=true&characterEncoding=utf8

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:jee="http://www.springframework.org/schema/jee" xmlns:tx="http://www.springframework.org/schema/tx"
??? xmlns:context="http://www.springframework.org/schema/context"
??? xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-2.5.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd"
??? default-lazy-init="true">

??? <description>Spring公共配置文件 </description>

??? 
??? <bean value="SYSTEM_PROPERTIES_MODE_OVERRIDE" />
??????? <property name="ignoreResourceNotFound" value="true" />
??????? <property name="locations">
??????????? <list>
??????????????? 
??????????????? <value>classpath*:/application.properties</value>
??????????????? 
??????????????? <value>classpath*:/application.local.properties</value>
??????????????? 
??????????????? 
??????????? </list>
??????? </property>
??? </bean>

??? 
??? <context:component-scan base-package="cn.puretext" />

??? 
??? <bean id="dataSourceContent" destroy-method="close">
??????? 
??????? <property name="driverClassName" value="com.mysql.jdbc.Driver" />
??????? <property name="url" value="${jdbc.urlContent}" />
??????? <property name="username" value="${jdbc.username}" />
??????? <property name="password" value="${jdbc.password}" />

??????? 
??????? <property name="initialSize" value="5" />
??????? <property name="maxActive" value="100" />
??????? <property name="maxIdle" value="30" />
??????? <property name="maxWait" value="1000" />
??????? <property name="poolPreparedStatements" value="true" />
??????? <property name="defaultAutoCommit" value="false" />
??? </bean>
??? <bean id="dataSourceIndex" destroy-method="close">
??????? 
??????? <property name="driverClassName" value="com.mysql.jdbc.Driver" />
??????? <property name="url" value="${jdbc.urlIndex}" />
??????? <property name="username" value="${jdbc.username}" />
??????? <property name="password" value="${jdbc.password}" />

??????? 
??????? <property name="initialSize" value="5" />
??????? <property name="maxActive" value="100" />
??????? <property name="maxIdle" value="30" />
??????? <property name="maxWait" value="1000" />
??????? <property name="poolPreparedStatements" value="true" />
??????? <property name="defaultAutoCommit" value="false" />
??? </bean>

??? 
??? 

??? 
??? <bean id="sessionFactory" ref="dataSourceContent" />
??????? <property name="namingStrategy">
??????????? <bean />
??????? </property>
??????? <property name="hibernateProperties">
??????????? <props>
??????????????? <prop key="hibernate.dialect">org.hibernate.dialect.MySQL5InnoDBDialect</prop>
??????????????? <prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
??????????????? <prop key="hibernate.format_sql">${hibernate.format_sql}</prop>
??????????????? <prop key="hibernate.cache.provider_class">org.hibernate.cache.EhCacheProvider
??????????????? </prop>
??????????????? <prop key="hibernate.cache.provider_configuration_file_resource_path">${hibernate.ehcache_config_file}</prop>
??????????? </props>
??????? </property>
??????? <property name="packagesToScan" value="cn.puretext.entity.*" />
??? </bean>

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

??? 
??? 

??? 
??? <tx:annotation-driven transaction-manager="transactionManager" />
</beans>

这个时候运行上一篇文章中写好的单元测试DaoTest.java，结果发现还是会出错，错误原因如下：
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'cn.puretext.unit.service.DaoTest': Autowiring of methods failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire method: public void org.springframework.test.context.junit4.AbstractTransactionalJUnit4SpringContextTests.setDataSource(javax.sql.DataSource); nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No unique bean of type [javax.sql.DataSource] is defined: expected single matching bean but found 2: [dataSourceContent, dataSourceIndex]

经过分析，发现是测试类的基类需要注入DataSource，而现在配置了多个DataSource，所以Spring不知道哪个DataSource匹配了，所以需要改写DaoTest.java，如下：
package cn.puretext.unit.service;

import java.util.List;

import javax.annotation.Resource;
import javax.sql.DataSource;

import org.junit.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springside.modules.orm.Page;
import org.springside.modules.test.junit4.SpringTxTestCase;

import cn.puretext.dao.ArticleDao;
import cn.puretext.entity.web.Article;

public class DaoTest extends SpringTxTestCase {
??? @Autowired
??? private ArticleDao articleDao;
???
??? public ArticleDao getArticleDao() {
??????? return articleDao;
??? }

??? public void setArticleDao(ArticleDao articleDao) {
??????? this.articleDao = articleDao;
??? }

??? @Override
??? @Resource(name = "dataSourceContent")
??? public void setDataSource(DataSource dataSource) {
??????? // TODO Auto-generated method stub
??????? super.setDataSource(dataSource);
??? }

??? @Test
??? public void addArticle() {
??????? Article article = new Article();
??????? article.setSubject("article test");
??????? article.setContent("article test");
??????? articleDao.save(article);
??? }
???
??? @Test
??? public void pageQuery() {
??????? Page<Article> page = new Page<Article>();
??????? page.setPageSize(10);
??????? page.setPageNo(2);
??????? page = articleDao.getAll(page);
??????? List<Article> articles = page.getResult();
??? }
}

改变的内容主要为重写了基类中的setDataSource方法，并使用@Resource注解指定使用的DataSource为dataSourceContent。经过修改后，单元测试成功运行。

第二步，配置多个SessionFactory，配置文件如下：
<?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:jee="http://www.springframework.org/schema/jee" xmlns:tx="http://www.springframework.org/schema/tx"
??? xmlns:context="http://www.springframework.org/schema/context"
??? xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-2.5.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd"
??? default-lazy-init="true">

??? <description>Spring公共配置文件 </description>

??? 
??? <bean value="SYSTEM_PROPERTIES_MODE_OVERRIDE" />
??????? <property name="ignoreResourceNotFound" value="true" />
??????? <property name="locations">
??????????? <list>
??????????????? 
??????????????? <value>classpath*:/application.properties</value>
??????????????? 
??????????????? <value>classpath*:/application.local.properties</value>
??????????????? 
??????????????? 
??????????? </list>
??????? </property>
??? </bean>

??? 
??? <context:component-scan base-package="cn.puretext" />

??? 
??? <bean id="dataSourceContent" destroy-method="close">
??????? 
??????? <property name="driverClassName" value="com.mysql.jdbc.Driver" />
??????? <property name="url" value="${jdbc.urlContent}" />
??????? <property name="username" value="${jdbc.username}" />
??????? <property name="password" value="${jdbc.password}" />

??????? 
??????? <property name="initialSize" value="5" />
??????? <property name="maxActive" value="100" />
??????? <property name="maxIdle" value="30" />
??????? <property name="maxWait" value="1000" />
??????? <property name="poolPreparedStatements" value="true" />
??????? <property name="defaultAutoCommit" value="false" />
??? </bean>
??? <bean id="dataSourceIndex" destroy-method="close">
??????? 
??????? <property name="driverClassName" value="com.mysql.jdbc.Driver" />
??????? <property name="url" value="${jdbc.urlIndex}" />
??????? <property name="username" value="${jdbc.username}" />
??????? <property name="password" value="${jdbc.password}" />

??????? 
??????? <property name="initialSize" value="5" />
??????? <property name="maxActive" value="100" />
??????? <property name="maxIdle" value="30" />
??????? <property name="maxWait" value="1000" />
??????? <property name="poolPreparedStatements" value="true" />
??????? <property name="defaultAutoCommit" value="false" />
??? </bean>

??? 
??? 

??? 
??? <bean id="sessionFactoryContent" ref="dataSourceContent" />
??????? <property name="namingStrategy">
??????????? <bean />
??????? </property>
??????? <property name="hibernateProperties">
??????????? <props>
??????????????? <prop key="hibernate.dialect">org.hibernate.dialect.MySQL5InnoDBDialect</prop>
??????????????? <prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
??????????????? <prop key="hibernate.format_sql">${hibernate.format_sql}</prop>
??????????????? <prop key="hibernate.cache.provider_class">org.hibernate.cache.EhCacheProvider
??????????????? </prop>
??????????????? <prop key="hibernate.cache.provider_configuration_file_resource_path">${hibernate.ehcache_config_file}</prop>
??????????? </props>
??????? </property>
??????? <property name="packagesToScan" value="cn.puretext.entity.*" />
??? </bean>
??? <bean id="sessionFactoryIndex" ref="dataSourceIndex" />
??????? <property name="namingStrategy">
??????????? <bean />
??????? </property>
??????? <property name="hibernateProperties">
??????????? <props>
??????????????? <prop key="hibernate.dialect">org.hibernate.dialect.MySQL5InnoDBDialect</prop>
??????????????? <prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
??????????????? <prop key="hibernate.format_sql">${hibernate.format_sql}</prop>
??????????????? <prop key="hibernate.cache.provider_class">org.hibernate.cache.EhCacheProvider
??????????????? </prop>
??????????????? <prop key="hibernate.cache.provider_configuration_file_resource_path">${hibernate.ehcache_config_file}</prop>
??????????? </props>
??????? </property>
??????? <property name="packagesToScan" value="cn.puretext.entity.*" />
??? </bean>

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

??? 
??? 

??? 
??? <tx:annotation-driven transaction-manager="transactionManager" />
</beans>

运行单元测试，报错，错误代码如下：
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'cn.puretext.unit.service.DaoTest': Autowiring of fields failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private cn.puretext.dao.ArticleDao cn.puretext.unit.service.DaoTest.articleDao; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'articleDao': Autowiring of methods failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire method: public void org.springside.modules.orm.hibernate.SimpleHibernateDao.setSessionFactory(org.hibernate.SessionFactory); nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No unique bean of type [org.hibernate.SessionFactory] is defined: expected single matching bean but found 2: [sessionFactoryContent, sessionFactoryIndex]

这和上面出现的错误是异曲同工的，只不过这次是ArticleDao类里面不知道注入哪一个SessionFactory，因此，需要修改ArticleDao类，重写setSessionFactory方法，并用@Resource注解指定，如下：
package cn.puretext.dao;

import javax.annotation.Resource;

import org.hibernate.SessionFactory;
import org.springframework.stereotype.Repository;
import org.springside.modules.orm.hibernate.HibernateDao;

import cn.puretext.entity.web.Article;

@Repository
public class ArticleDao extends HibernateDao<Article, Long> {

??? @Override
??? @Resource(name = "sessionFactoryContent")
??? public void setSessionFactory(SessionFactory sessionFactory) {
??????? // TODO Auto-generated method stub
??????? super.setSessionFactory(sessionFactory);
??? }

}

运行单元测试，成功。

第三步、配置多个TransactionManager，如下：
<?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:jee="http://www.springframework.org/schema/jee" xmlns:tx="http://www.springframework.org/schema/tx"
??? xmlns:context="http://www.springframework.org/schema/context"
??? xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-2.5.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd"
??? default-lazy-init="true">

??? <description>Spring公共配置文件 </description>

??? 
??? <bean value="SYSTEM_PROPERTIES_MODE_OVERRIDE" />
??????? <property name="ignoreResourceNotFound" value="true" />
??????? <property name="locations">
??????????? <list>
??????????????? 
??????????????? <value>classpath*:/application.properties</value>
??????????????? 
??????????????? <value>classpath*:/application.local.properties</value>
??????????????? 
??????????????? 
??????????? </list>
??????? </property>
??? </bean>

??? 
??? <context:component-scan base-package="cn.puretext" />

??? 
??? <bean id="dataSourceContent" destroy-method="close">
??????? 
??????? <property name="driverClassName" value="com.mysql.jdbc.Driver" />
??????? <property name="url" value="${jdbc.urlContent}" />
??????? <property name="username" value="${jdbc.username}" />
??????? <property name="password" value="${jdbc.password}" />

??????? 
??????? <property name="initialSize" value="5" />
??????? <property name="maxActive" value="100" />
??????? <property name="maxIdle" value="30" />
??????? <property name="maxWait" value="1000" />
??????? <property name="poolPreparedStatements" value="true" />
??????? <property name="defaultAutoCommit" value="false" />
??? </bean>
??? <bean id="dataSourceIndex" destroy-method="close">
??????? 
??????? <property name="driverClassName" value="com.mysql.jdbc.Driver" />
??????? <property name="url" value="${jdbc.urlIndex}" />
??????? <property name="username" value="${jdbc.username}" />
??????? <property name="password" value="${jdbc.password}" />

??????? 
??????? <property name="initialSize" value="5" />
??????? <property name="maxActive" value="100" />
??????? <property name="maxIdle" value="30" />
??????? <property name="maxWait" value="1000" />
??????? <property name="poolPreparedStatements" value="true" />
??????? <property name="defaultAutoCommit" value="false" />
??? </bean>

??? 
??? 

??? 
??? <bean id="sessionFactoryContent" ref="dataSourceContent" />
??????? <property name="namingStrategy">
??????????? <bean />
??????? </property>
??????? <property name="hibernateProperties">
??????????? <props>
??????????????? <prop key="hibernate.dialect">org.hibernate.dialect.MySQL5InnoDBDialect</prop>
??????????????? <prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
??????????????? <prop key="hibernate.format_sql">${hibernate.format_sql}</prop>
??????????????? <prop key="hibernate.cache.provider_class">org.hibernate.cache.EhCacheProvider
??????????????? </prop>
??????????????? <prop key="hibernate.cache.provider_configuration_file_resource_path">${hibernate.ehcache_config_file}</prop>
??????????? </props>
??????? </property>
??????? <property name="packagesToScan" value="cn.puretext.entity.*" />
??? </bean>
??? <bean id="sessionFactoryIndex" ref="dataSourceIndex" />
??????? <property name="namingStrategy">
??????????? <bean />
??????? </property>
??????? <property name="hibernateProperties">
??????????? <props>
??????????????? <prop key="hibernate.dialect">org.hibernate.dialect.MySQL5InnoDBDialect</prop>
??????????????? <prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
??????????????? <prop key="hibernate.format_sql">${hibernate.format_sql}</prop>
??????????????? <prop key="hibernate.cache.provider_class">org.hibernate.cache.EhCacheProvider
??????????????? </prop>
??????????????? <prop key="hibernate.cache.provider_configuration_file_resource_path">${hibernate.ehcache_config_file}</prop>
??????????? </props>
??????? </property>
??????? <property name="packagesToScan" value="cn.puretext.entity.*" />
??? </bean>

??? 
??? <bean id="transactionManagerContent" ref="sessionFactoryContent" />
??? </bean>
??? <bean id="transactionManagerIndex" ref="sessionFactoryIndex" />
??? </bean>

??? 
??? 

??? 
??? <tx:annotation-driven transaction-manager="transactionManagerContent" />
</beans>

这个时候运行还是会出错，出错的原因为 org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'transactionManager' is defined，因为该出错信息很短，我也难以找出究竟是哪个地方需要名为“transactionManager”的事务管理器，改个名字都不行，看来Spring的自动注入有时候也错综复杂害人不浅。不过，如果把上面的其中一个名字改成“transactionManger”，另外一个名字不改，运行是成功的，如下：

??? <bean id="transactionManager" ref="sessionFactoryContent" />
??? </bean>
??? <bean id="transactionManagerIndex" ref="sessionFactoryIndex" />
??? </bean>

这个时候得出结论是，可以配置多个TransactionManager，但是必须有一个的名字是transactionManager。

第四步、配置多个<tx:annotation-driven/>，如下：
??? 
??? <tx:annotation-driven transaction-manager="transactionManager" />
??? <tx:annotation-driven transaction-manager="transactionManagerIndex" />

运行测试，天啦，竟然成功了。和我之前预料的完全不一样，居然在一个配置文件中配置多个<tx:annotation-driven/>一点问题都没有。那么在使用@Transactional的地方，它真的能够选择正确的事务管理器吗？我不得不写更多的代码来进行测试。那就针对索引数据库中的表写一个Entity，写一个Dao测试一下吧。

代码如下：
package cn.puretext.entity.web;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Table;

import org.hibernate.annotations.Cache;
import org.hibernate.annotations.CacheConcurrencyStrategy;

import cn.puretext.entity.IdEntity;

@Entity
// 表名与类名不相同时重新定义表名.
@Table(name = "articles")
// 默认的缓存策略.
@Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
public class ArticleIndex extends IdEntity {
??? private String subject;
??? private String webServer;

??? public String getSubject() {
??????? return subject;
??? }

??? public void setSubject(String subject) {
??????? this.subject = subject;
??? }
??? @Column(name = "webserver")
??? public String getWebServer() {
??????? return webServer;
??? }

??? public void setWebServer(String webServer) {
??????? this.webServer = webServer;
??? }
}

package cn.puretext.dao;

import javax.annotation.Resource;

import org.hibernate.SessionFactory;
import org.springframework.stereotype.Repository;
import org.springside.modules.orm.hibernate.HibernateDao;

import cn.puretext.entity.web.ArticleIndex;

@Repository
public class ArticleIndexDao extends HibernateDao<ArticleIndex, Long> {
??? @Override
??? @Resource(name = "sessionFactoryIndex")
??? public void setSessionFactory(SessionFactory sessionFactory) {
??????? // TODO Auto-generated method stub
??????? super.setSessionFactory(sessionFactory);
??? }
}

package cn.puretext.unit.service;

import java.util.List;

import javax.annotation.Resource;
import javax.sql.DataSource;

import org.junit.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.transaction.annotation.Transactional;
import org.springside.modules.orm.Page;
import org.springside.modules.test.junit4.SpringTxTestCase;

import cn.puretext.dao.ArticleDao;
import cn.puretext.dao.ArticleIndexDao;
import cn.puretext.entity.web.Article;
import cn.puretext.entity.web.ArticleIndex;
import cn.puretext.service.ServiceException;

public class DaoTest extends SpringTxTestCase {
??? @Autowired
??? private ArticleDao articleDao;
??? @Autowired
??? private ArticleIndexDao articleIndexDao;
???
??? public void setArticleIndexDao(ArticleIndexDao articleIndexDao) {
??????? this.articleIndexDao = articleIndexDao;
??? }

??? public void setArticleDao(ArticleDao articleDao) {
??????? this.articleDao = articleDao;
??? }

??? @Override
??? @Resource(name = "dataSourceContent")
??? public void setDataSource(DataSource dataSource) {
??????? // TODO Auto-generated method stub
??????? super.setDataSource(dataSource);
??? }

??? @Test
??? @Transactional
??? public void addArticle() {
??????? Article article = new Article();
??????? article.setSubject("article test");
??????? article.setContent("article test");
??????? articleDao.save(article);
??? }

??? @Test
??? @Transactional
??? public void pageQuery() {
??????? Page<Article> page = new Page<Article>();
??????? page.setPageSize(10);
??????? page.setPageNo(2);
??????? page = articleDao.getAll(page);
??????? List<Article> articles = page.getResult();
??? }
???
??? @Test
??? @Transactional
??? public void addIndex() {
??????? ArticleIndex articleIndex = new ArticleIndex();
??????? articleIndex.setSubject("test");
??????? articleIndex.setWebServer("www001");
??????? articleIndexDao.save(articleIndex);
??? }
???
??? @Test
??? @Transactional
??? public void addArticleAndAddIndex() {
??????? addArticle();
??????? addIndex();
??????? throw new ServiceException("测试事务回滚");
??? }
}

运行测试，结果还是成功的。到目前，发现在一个项目中使用多个TransactionManager可以正常运行，但是有两个问题需要考虑：
1、为什么必须得有一个TransactionManager名字为transactionManager？
2、这两个TransactionManager真的能正常工作吗？
3、OpenSessionInView的问题怎么解决？

以上的三个问题在单元测试中是不能找出答案的，我只好再去写Action层的代码，期望能够从中得到线索。经过一天艰苦的努力，终于真相大白：
1、并不是必须有一个TransactionManager的名字为transactionMananger，这只是单元测试在搞鬼，在真实的Web环境中，无论两个TransactionManager取什么名字都可以，运行不会报错。所以这个答案很明确，是因为单元测试的基类需要一个名为 transactionMananger的事务管理器。
2、在单元测试中，只能测试Dao类和Entity类能否正常工作，但是由于单元测试结束后事务会自动回滚，不会把数据写入到数据库中，所以没有办法确定两个TransactionManager能否正常工作。在真实的Web环境中，问题很快就浮出水面，只有一个数据库中有数据，另外一个数据库中没有，经过调整<tx:annotation-driven/>的位置并对比分析，发现只有放在前面的TransactionMananger的事务能够正常提交，放在后面的TransactionManager的事务不能提交，所以永远只有一个数据库里面有数据。
3、如果早一点脱离单元测试而进入真实的Web环境，就会早一点发现OpenSessionInViewFilter的问题，因为只要配置多个 SessionFactory，运行的时候OpenSessionInViewFilter就会报错。为了解决这个问题，我只能去阅读 OpenSessionInViewFilter的源代码，发现它在将Session绑定到线程的时候用的是Map，而且使用 SessionFactory作为Map的key，这就说明在线程中绑定多个Session不会冲突，也进一步说明可以在web.xml中配置多个 OpenSessionInViewFilter。而我也正是通过配置多个OpenSessionInViewFilter来解决问题的。我的 web.xml文件如下：
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
??? xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">

??? <display-name>PureText</display-name>
??? 
??? <context-param>
??????? <param-name>contextConfigLocation</param-name>
??????? <param-value>classpath*:/applicationContext*.xml</param-value>
??? </context-param>

??? 
??? <filter>
??????? <filter-name>encodingFilter</filter-name>
??????? <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
??????? <init-param>
??????????? <param-name>encoding</param-name>
??????????? <param-value>UTF-8</param-value>
??????? </init-param>
??????? <init-param>
??????????? <param-name>forceEncoding</param-name>
??????????? <param-value>true</param-value>
??????? </init-param>
??? </filter>

??? <filter>
??????? <filter-name>hibernateOpenSessionInViewFilterContent</filter-name>
??????? <filter-class>org.springside.modules.orm.hibernate.OpenSessionInViewFilter</filter-class>
??????? <init-param>
??????????? <param-name>excludeSuffixs</param-name>
??????????? <param-value>js,css,jpg,gif</param-value>
??????? </init-param>
??????? <init-param>?????
?????????????? <param-name>sessionFactoryBeanName</param-name>
??????????? <param-value>sessionFactoryContent</param-value>??
??????? </init-param>???
??? </filter>
??? <filter>
??????? <filter-name>hibernateOpenSessionInViewFilterIndex</filter-name>
??????? <filter-class>org.springside.modules.orm.hibernate.OpenSessionInViewFilter</filter-class>
??????? <init-param>
??????????? <param-name>excludeSuffixs</param-name>
??????????? <param-value>js,css,jpg,gif</param-value>
??????? </init-param>
??????? <init-param>?????
?????????????? <param-name>sessionFactoryBeanName</param-name>
??????????? <param-value>sessionFactoryIndex</param-value>??
??????? </init-param>???
??? </filter>
??? 
??? <filter>
??????? <filter-name>springSecurityFilterChain</filter-name>
??????? <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
??? </filter>

??? 
??? <filter>
??????? <filter-name>struts2Filter</filter-name>
??????? <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
??? </filter>

??? <filter-mapping>
??????? <filter-name>encodingFilter</filter-name>
??????? <url-pattern>/*</url-pattern>
??? </filter-mapping>

??? <filter-mapping>
??????? <filter-name>springSecurityFilterChain</filter-name>
??????? <url-pattern>/*</url-pattern>
??? </filter-mapping>
??? <filter-mapping>
??????? <filter-name>hibernateOpenSessionInViewFilterContent</filter-name>
??????? <url-pattern>/*</url-pattern>
??? </filter-mapping>
??? <filter-mapping>
??????? <filter-name>hibernateOpenSessionInViewFilterIndex</filter-name>
??????? <url-pattern>/*</url-pattern>
??? </filter-mapping>
??? <filter-mapping>
??????? <filter-name>struts2Filter</filter-name>
??????? <url-pattern>/*</url-pattern>
??? </filter-mapping>

??? 
??? <listener>
??????? <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
??? </listener>

??? 
??? <listener>
??????? <listener-class>org.springframework.web.util.IntrospectorCleanupListener</listener-class>
??? </listener>

??? 
??? <session-config>
??????? <session-timeout>20</session-timeout>
??? </session-config>

??? 
??? <error-page>
??????? <exception-type>java.lang.Throwable</exception-type>
??????? <location>/common/500.jsp</location>
??? </error-page>
??? <error-page>
??????? <error-code>500</error-code>
??????? <location>/common/500.jsp</location>
??? </error-page>
??? <error-page>
??????? <error-code>404</error-code>
??????? <location>/common/404.jsp</location>
??? </error-page>
??? <error-page>
??????? <error-code>403</error-code>
??????? <location>/common/403.jsp</location>
??? </error-page>
</web-app>

经过上面的分析，发现使用多个TransactionManager是不可行的（这个时候我在想，也许不使用Annotation就可以使用多个 TransactionMananger吧，毕竟Spring的AOP应该是可以把不同的TransactionManager插入到不同的类和方法中，但是谁愿意走回头路呢？毕竟都已经是@Transactional的年代了），虽然运行不会报错，但是只有一个TransactionManager的事务能够正常提交。所以测试进入下一步：

第五步、使用JTATransactionManager

简单地修改配置文件，使用JTATransactionManager做为事务管理器，配置文件我就不列出来了，运行，结果抱错，错误信息如下：
org.springframework.beans.factory.BeanCreationException: Error creating bean with name '_filterChainProxy': Initialization of bean failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '_filterChainList': Cannot create inner bean '(inner bean)' of type [org.springframework.security.config.OrderedFilterBeanDefinitionDecorator$OrderedFilterDecorator] while setting bean property 'filters' with key [10]; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)': Cannot resolve reference to bean 'filterSecurityInterceptor' while setting constructor argument; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'filterSecurityInterceptor' defined in file [D:\Temp\1-PureText\WEB-INF\classes\applicationContext-security.xml]: Cannot resolve reference to bean 'databaseDefinitionSource' while setting bean property 'objectDefinitionSource'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'databaseDefinitionSource': FactoryBean threw exception on object creation; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.transaction.interceptor.TransactionInterceptor#0': Cannot resolve reference to bean 'transactionManager' while setting bean property 'transactionManager'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'transactionManager' defined in file [D:\Temp\1-PureText\WEB-INF\classes\applicationContext.xml]: Invocation of init method failed; nested exception is java.lang.IllegalStateException: No JTA UserTransaction available - specify either 'userTransaction' or 'userTransactionName' or 'transactionManager' or 'transactionManagerName'

通过分析，发现其中最关键的一句是No JTA UserTransaction available，看来，我们只能进入到第六步，使用GlassFish了。

第六步、将项目部署到GlassFish中

将项目简单地部署到GlassFish中之后，项目可以成功运行，没有报错，说明JTA UserTransaction问题解决了，但是检查数据库却发现依然没有数据，看来JTATransactionManager不仅要和应用服务器配合使用，还要和JNDI数据源一起使用。将数据源的配置修改为JNDI后，问题解决。下面是我的配置文件：
<?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:jee="http://www.springframework.org/schema/jee" xmlns:tx="http://www.springframework.org/schema/tx"
??? xmlns:context="http://www.springframework.org/schema/context"
??? xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-2.5.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd"
??? default-lazy-init="true">

??? <description>Spring公共配置文件 </description>

??? 
??? <bean value="SYSTEM_PROPERTIES_MODE_OVERRIDE" />
??????? <property name="ignoreResourceNotFound" value="true" />
??????? <property name="locations">
??????????? <list>
??????????????? 
??????????????? <value>classpath*:/application.properties</value>
??????????????? 
??????????????? <value>classpath*:/application.local.properties</value>
??????????????? 
??????????????? 
??????????? </list>
??????? </property>
??? </bean>

??? 
??? <context:component-scan base-package="cn.puretext" />

??? 
??? <jee:jndi-lookup id="dataSourceContent" jndi-name="jdbc/dataSourceContent" />
??? <jee:jndi-lookup id="dataSourceIndex" jndi-name="jdbc/dataSourceIndex" />

??? 
??? <bean id="sessionFactoryContent" ref="dataSourceContent" />
??????? <property name="namingStrategy">
??????????? <bean />
??????? </property>
??????? <property name="hibernateProperties">
??????????? <props>
??????????????? <prop key="hibernate.dialect">org.hibernate.dialect.MySQL5InnoDBDialect</prop>
??????????????? <prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
??????????????? <prop key="hibernate.format_sql">${hibernate.format_sql}</prop>
??????????????? <prop key="hibernate.cache.provider_class">org.hibernate.cache.EhCacheProvider
??????????????? </prop>
??????????????? <prop key="hibernate.cache.provider_configuration_file_resource_path">${hibernate.ehcache_config_file}</prop>
??????????? </props>
??????? </property>
??????? <property name="packagesToScan" value="cn.puretext.entity.*" />
??? </bean>
??? <bean id="sessionFactoryIndex" ref="dataSourceIndex" />
??????? <property name="namingStrategy">
??????????? <bean />
??????? </property>
??????? <property name="hibernateProperties">
??????????? <props>
??????????????? <prop key="hibernate.dialect">org.hibernate.dialect.MySQL5InnoDBDialect</prop>
??????????????? <prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
??????????????? <prop key="hibernate.format_sql">${hibernate.format_sql}</prop>
??????????????? <prop key="hibernate.cache.provider_class">org.hibernate.cache.EhCacheProvider
??????????????? </prop>
??????????????? <prop key="hibernate.cache.provider_configuration_file_resource_path">${hibernate.ehcache_config_file}</prop>
??????????? </props>
??????? </property>
??????? <property name="packagesToScan" value="cn.puretext.entity.*" />
??? </bean>

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

??? 
??? <tx:annotation-driven transaction-manager="transactionManager" />
???
</beans>

最后，我得出的结论是：要想使用多个数据库，就必须使用JTATransactionMananger，必须使用GlassFish等应用服务器而不是Tomcat，必须使用JNDI来管理dataSource。

如果一定要使用Tomcat呢？

这确实是一个难题，但是并不代表着没有解决办法。经过广泛的Google一番之后，终于发现了一个好东东，那就是JOTM，它的全称就是Java Open Transaction Mananger，它的作用就是可以单独提供JTA事务管理的功能，不需要应用服务器。JOTM的使用方法有两种，一种就是把它配置到项目中，和 Spring结合起来使用，另外一种就是把它配置到Tomcat中，这时，Tomcat摇身一变就成了和GlassFish一样的能够提供JTA功能的服务器了。

JOTM的官方网站为http://jotm.ow2.org，这是它的新网站，旧网站为http://jotm.objectweb.org。

我选择了把JOTM 2.0.11整合到Tomcat中的方法进行了测试，结果发现还是不能够正常运行，我使用的是JOTM2.0.11，Tomcat 6.0.20，JKD 6 Update10。看来还得继续折腾下去了。

另外一个开源的JTA事务管理器是Atomikos，它供了事务管理和连接池，不需要应用服务器支持，其官方网站为http://www.atomikos.com/

我的异常网推荐解决方案：org.springframework.beans.factory.BeanCreationException:,http://www.myexception.cn/j2ee/10759.html

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