本节将介绍JOTM在Spring中的配置。 JOTM(Java Open Transaction Manager)是ObjectWeb的一个开源JTA实现,本身也是开源应用程序服务器JOnAS(Java Open Application Server)的一部分,为其提供JTA分布式事务的功能。Spring对JOTM提供了较好的支持,提供了一个org.springframework.transaction.jta.JotmFactoryBean的支持类,在Spring2.0中也包含了JOTM相关的一些library。 jotm的下载地址为http://jotm.objectweb.org,最新版本为2.0.10. 下载完成后解压缩,然后打开jotm下面conf文件夹,拷贝carol.properties文件到classpath中,并修改这个文件如下 carol.properties
# do not use CAROL JNDI wrapper carol.start.jndi=false # do not start a name server carol.start.ns=false # Naming Factory carol.jndi.java.naming.factory.url.pkgs=org.apache.naming 上面配置文件的目的是不使用JNDI的方式来加载JOTM的配置,当然也可以根据需要选择其它的一些配置,例如JTOM所提供的默认配置。 然后开始在Spring上下文中配置JOTM,在classpath中建立一个ApplicationContext-jotm.xml,配置如下 ApplicationContext-jotm.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" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd"> <bean id="jotm" class="org.springframework.transaction.jta.JotmFactoryBean"/> <bean id="txManager" class="org.springframework.transaction.jta.JtaTransactionManager"> <property name="userTransaction" ref="jotm" /> </bean> <bean id="ds1" class="org.enhydra.jdbc.pool.StandardXAPoolDataSource" destroy-method="shutdown"> <property name="dataSource"> <bean class="org.enhydra.jdbc.standard.StandardXADataSource" destroy-method="shutdown"> <property name="transactionManager" ref="jotm" /> <property name="driverName" value="com.mysql.jdbc.Driver" /> <property name="url" value="jdbc:MySQL://localhost:3306/test" /> </bean> </property> <property name="user" value="root" /> <property name="password" value="admin" /> </bean> <bean id="ds2" class="org.enhydra.jdbc.pool.StandardXAPoolDataSource" destroy-method="shutdown"> <property name="dataSource"> <bean class="org.enhydra.jdbc.standard.StandardXADataSource" destroy-method="shutdown"> <property name="transactionManager" ref="jotm" /> <property name="driverName" value="com.mysql.jdbc.Driver" /> <property name="url" value="jdbc:MySQL://localhost:3306/test2" /> </bean> </property> <property name="user" value="root" /> <property name="password" value="admin" /> </bean> <bean id="template1" class="org.springframework.jdbc.core.JdbcTemplate"> <property name="dataSource" ref="ds1" /> </bean> <bean id="template2" class="org.springframework.jdbc.core.JdbcTemplate"> <property name="dataSource" ref="ds2" /> </bean> <bean id="dao1" class="com.xa.dao.UserDao1"> <property name="jdbcTemplate"> <ref bean="template1"></ref> </property> </bean> <bean id="dao2" class="com.xa.dao.UserDao2"> <property name="jdbcTemplate"> <ref bean="template2"></ref> </property> </bean> <bean id="userServiceTarget" class="com.xa.service.UserServiceImpl"> <property name="dao1" ref="dao1"/> <property name="dao2" ref="dao2"/> </bean> <bean id="userTest" class="org.springframework.transaction.interceptor.TransactionProxyFactoryBean"> <property name="transactionManager"> <ref bean="txManager"/> </property> <property name="target"> <ref bean="userServiceTarget"/> </property> <property name="transactionAttributes"> <props> <prop key="insert*">PROPAGATION_REQUIRED,-Exception</prop> </props> </property> </bean> </beans> 上面是一个完整的Spring上下文配置,可以看第一个bean “jotm”,实际上引用了Spring内部所提供的对JOTM支持的工厂类,参考下面的配置代码段
<bean id="jotm" class="org.springframework.transaction.jta.JotmFactoryBean"/> 随后,配置了JTA事务管理器,并且在管理器中使用上面所配置的jotm,如下面的代码
<bean id="txManager" class="org.springframework.transaction.jta.JtaTransactionManager"> <property name="userTransaction" ref="jotm" /> </bean> 再接下来就是配置多个数据源了,使用jotm提供的org.enhydra.jdbc.pool.StandardXAPoolDataSource类,根据类名可以明确地看出它是用以配置多个数据源的啦,配置的代码如下
<bean id="ds1" class="org.enhydra.jdbc.pool.StandardXAPoolDataSource" destroy-method="shutdown"> <property name="dataSource"> <bean class="org.enhydra.jdbc.standard.StandardXADataSource" destroy-method="shutdown"> <property name="transactionManager" ref="jotm" /> <property name="driverName" value="com.mysql.jdbc.Driver" /> <property name="url" value="jdbc:MySQL://localhost:3306/test" /> </bean> </property> <property name="user" value="root" /> <property name="password" value="admin" /> </bean> <bean id="ds2" class="org.enhydra.jdbc.pool.StandardXAPoolDataSource" destroy-method="shutdown"> <property name="dataSource"> <bean class="org.enhydra.jdbc.standard.StandardXADataSource" destroy-method="shutdown"> <property name="transactionManager" ref="jotm" /> <property name="driverName" value="com.mysql.jdbc.Driver" /> <property name="url" value="jdbc:MySQL://localhost:3306/test2" /> </bean> </property> <property name="user" value="root" /> <property name="password" value="admin" /> </bean> 这里配置的两个数据源都连接到本地的mysql,实际上可以连接到不同的db server和不同类型的数据库,已经经过测试,这里为了方便,在本地建立了两个不同的数据库(test,test2)做测试。 随后的配置基本上和普通的Spring上下文配置相同了,根据不同的数据源配置两个jdbcTemplate,两个dao分别引用不同的jdbcTemplate, 将两个dao注入到UserService中, 最后将service纳入事务管理,并在事务代理配置中配置回滚规则,意思为如遇异常,则强制回滚内容。配置如下所示
<property name="transactionAttributes"> <props> <prop key="insert*">PROPAGATION_REQUIRED,-Exception</prop> </props> </property> 这样,一个使用JOTM JTA事务的简单应用算大致成型了,最后,写一个JUnit,来测试一下结果 TestXa.java
package com.xa; import org.springframework.context.ApplicationContext; import org.springframework.test.AbstractDependencyInjectionSpringContextTests; import com.xa.service.UserService; public class TestXa extends AbstractDependencyInjectionSpringContextTests { protected String[] getConfigLocations() { return new String[] { "classpath:ApplicationContext-jotm.xml" }; } public void testInsertBothDatabase() { ApplicationContext ctx = this.getApplicationContext(); UserService ut = (UserService)ctx.getBean("userTest"); try { ut.insertBothDatabase("1", null); } catch (Exception e) { e.printStackTrace(); } } } 在test中,调用了UserService的insertBothDatabase方法,有两个参数,userId和UserName,另外在方法的实现中调用了两个使用不同数据源dao,分别向两个不同的数据库插入输入,而test2数据库的xa_test表中,name字段是不允许为空的,因此,在插入test2数据库时会失败. 运行这个test,然后察看数据库结果:),test和test2数据库中都没有插入成功,看serviceImpl中的代码可以知道,逻辑上dao1会先于dao2执行,但是由于JTA事务,在dao2插入数据出现异常时整个事务被回滚,由于事务被配置在service层,dao1和dao2都被纳入一个事务进行管理,呵呵。修改一下方法的参数,修改为
ut.insertBothDatabase("1", "name1"); 然后再试试test看数据库结果,如何? |
1.web.xml
<servlet> <servlet-name>Dispatcher</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>/WEB-INF/classes/applicationContext.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>Dispatcher</servlet-name> <url-pattern>*.do</url-pattern> </servlet-mapping> 2.加入编码格式
<filter> <filter-name>Set Character Encoding</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> </filter> <filter-mapping> <filter-name>Set Character Encoding</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> 3.由于spring 3.0 里不在提供对jotm的封装,我们可以手动的编写加入代码如下
/* * Copyright 20010-2011 */ package com.demo.spring.jotm; import javax.naming.NamingException; import javax.transaction.SystemException; import org.objectweb.jotm.Current; import org.objectweb.jotm.Jotm; import org.springframework.beans.factory.DisposableBean; import org.springframework.beans.factory.FactoryBean; /** * @author fenglingcorp */ @SuppressWarnings("rawtypes") public class JotmFactoryBean implements FactoryBean, DisposableBean { private Current jotmCurrent; private Jotm jotm; public JotmFactoryBean() throws NamingException { // Check for already active JOTM instance. this.jotmCurrent = Current.getCurrent(); // If none found, create new local JOTM instance. if (this.jotmCurrent == null) { // Only for use within the current Spring context: // local, not bound to registry. this.jotm = new Jotm(true, false); this.jotmCurrent = Current.getCurrent(); } } public void setDefaultTimeout(int defaultTimeout) { this.jotmCurrent.setDefaultTimeout(defaultTimeout); // The following is a JOTM oddity: should be used for demarcation // transaction only, // but is required here in order to actually get rid of JOTM's default // (60 seconds). try { this.jotmCurrent.setTransactionTimeout(defaultTimeout); } catch (SystemException ex) { // should never happen } } public Jotm getJotm() { return this.jotm; } public Object getObject() { return this.jotmCurrent; } public Class getObjectType() { return this.jotmCurrent.getClass(); } public boolean isSingleton() { return true; } public void destroy() { if (this.jotm != null) { this.jotm.stop(); } } } 4.加入jotm事务和xpool数据源
<!-- jotm --> <bean id="jotm" class="com.demo.spring.jotm.JotmFactoryBean" /> <bean id="transactionManager" class="org.springframework.transaction.jta.JtaTransactionManager"> <property name="userTransaction" ref="jotm" /> </bean> <!-- StandardXAPoolDataSourc 数据源 --> <bean id="dataSource" class="org.enhydra.jdbc.pool.StandardXAPoolDataSource"> <property name="dataSource"> <bean id="innerDataSource" class="org.enhydra.jdbc.standard.StandardXADataSource"> <property name="transactionManager"> <ref local="jotm" /> </property> <property name="driverName"> <value>${datasource.driverClassName}</value> </property> <property name="url"> <value>${datasource.g_db_w_url}</value> </property> <property name="user"> <value>${datasource.g_db_w_username}</value> </property> <property name="password"> <value>${datasource.g_db_w_password}</value> </property> </bean> </property> <property name="user"> <value>${datasource.g_db_w_username}</value> </property> <property name="password"> <value>${datasource.g_db_w_password}</value> </property> <property name="maxSize"> <value>5</value> </property> <property name="minSize"> <value>2</value> </property> </bean> 5.加入aop支持
发表评论
最新评论
|
评论