java架构搭建（四）--spring事务

浅浅的花香味﹌ 2022-03-30 12:38 76阅读 0赞

此篇接上篇（java架构搭建（三））继续 http://blog.csdn.net/lushuaiyin/article/details/8589938

先看一下applicationContext.xml的内容：

<?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:aop="http://www.springframework.org/schema/aop"
        xmlns:tx="http://www.springframework.org/schema/tx"
        xsi:schemaLocation="
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd
        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.0.xsd
        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd">
    
    	<bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
    	    <property name="locations">
    			<list>
    				<value>classpath:configure.properties</value>
    			</list>
    	     </property>		
    	</bean>
    	<bean id="sessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
    		<property name="hibernateProperties">
    			<props>
    				<prop key="hibernate.dialect">${hibernate.dialect}</prop>
    				<prop key="hibernate.query.substitutions">true=1,false=0</prop>
    				<prop key="hibernate.jdbc.batch_size">25</prop>
    				<prop key="hibernate.show_sql">true</prop>
    				<prop key="hibernate.format_sql">false</prop>
    				<prop key="hibernate.generate_statistics">false</prop>
    				<prop key="hibernate.cache.use_query_cache">false</prop>
    				<prop key="hibernate.cache.region_prefix">direct</prop>
    				<prop key="hibernate.cache.use_structured_entries">false</prop> 
    				<prop key="hibernate.cache.provider_class">org.hibernate.cache.EhCacheProvider</prop>
    				<prop key="hibernate.query.factory_class">org.hibernate.hql.ast.ASTQueryTranslatorFactory</prop> 
    				<prop key="hibernate.transaction.factory_class">org.hibernate.transaction.JDBCTransactionFactory</prop>				
    			</props>
    		</property>
    		<property name="dataSource"       ref="dataSource"/>
    		<property name="mappingDirectoryLocations">
    	       <list>
    	         <value>classpath:/org/first/config/</value>
    	         <value>classpath:/org/second/config/</value>
    	       </list>
            </property>
    	</bean>
    	
    	<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">
    		<property name="maxPoolSize" value="${c3p0.maxPoolSize}"/>
    		<property name="minPoolSize" value="${c3p0.minPoolSize}"/>
    		<property name="maxIdleTime" value="${c3p0.maxIdleTime}"/>
    		<property name="maxStatements" value="${c3p0.maxStatements}"/>
    		<property name="acquireIncrement" value="${c3p0.acquireIncrement}"/>
    		<property name="idleConnectionTestPeriod" value="${c3p0.idleConnectionTestPeriod}"/>
    		<property name="driverClass" value="${jdbc.driverClassName}"/>
    		<property name="jdbcUrl" value="${jdbc.url}"/>
    		<property name="user" value="${jdbc.username}"/>
    		<property name="password" value="${jdbc.password}"/>
    	</bean>
    	
    	
    	<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
            <property name="dataSource">
            	<ref bean="dataSource"/>
            </property>
        </bean>
        	
    	<bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager">
    		<property name="sessionFactory" ref="sessionFactory"/>
    	</bean>
    	
    	<bean id="transactionProxyTemplate" class="org.springframework.transaction.interceptor.TransactionProxyFactoryBean" abstract="true">
    		<property name="transactionManager" ref="transactionManager"/>
    		<property name="transactionAttributes">
    			<props>
    				<prop key="query*">PROPAGATION_REQUIRED</prop>
    				<prop key="*">PROPAGATION_REQUIRED</prop>
    			</props>
    		</property>
    	</bean>	
    	
    	
    	<import resource="classpath:/org/first/config/context_first.xml"/>
    	<import resource="classpath:/org/second/config/context_second.xml"/>
    </beans>

其中

即是对事务的配置，他需要注入sessionFactory。

下面还有配置一个事务代理：

这个事务代理模板是干嘛用的呢？先看看源码吧：

org.springframework.transaction.interceptor.TransactionProxyFactoryBean

/*jadclipse*/// Decompiled by Jad v1.5.8g. Copyright 2001 Pavel Kouznetsov.
    
    package org.springframework.transaction.interceptor;
    
    import java.util.Properties;
    import org.springframework.aop.Pointcut;
    import org.springframework.aop.framework.AbstractSingletonProxyFactoryBean;
    import org.springframework.aop.support.DefaultPointcutAdvisor;
    import org.springframework.beans.factory.BeanFactory;
    import org.springframework.beans.factory.BeanFactoryAware;
    import org.springframework.transaction.PlatformTransactionManager;
    
    // Referenced classes of package org.springframework.transaction.interceptor:
    //            TransactionInterceptor, TransactionAttributeSourceAdvisor, TransactionAttributeSource
    
    public class TransactionProxyFactoryBean extends AbstractSingletonProxyFactoryBean
        implements BeanFactoryAware
    {
    
        public TransactionProxyFactoryBean()
        {
        }
    
        public void setTransactionManager(PlatformTransactionManager transactionManager)
        {
            transactionInterceptor.setTransactionManager(transactionManager);
        }
    
        public void setTransactionAttributes(Properties transactionAttributes)
        {
            transactionInterceptor.setTransactionAttributes(transactionAttributes);
        }
    
        public void setTransactionAttributeSource(TransactionAttributeSource transactionAttributeSource)
        {
            transactionInterceptor.setTransactionAttributeSource(transactionAttributeSource);
        }
    
        public void setPointcut(Pointcut pointcut)
        {
            this.pointcut = pointcut;
        }
    
        public void setBeanFactory(BeanFactory beanFactory)
        {
            transactionInterceptor.setBeanFactory(beanFactory);
        }
    
        protected Object createMainInterceptor()
        {
            transactionInterceptor.afterPropertiesSet();
            if(pointcut != null)
                return new DefaultPointcutAdvisor(pointcut, transactionInterceptor);
            else
                return new TransactionAttributeSourceAdvisor(transactionInterceptor);
        }
    
        private final TransactionInterceptor transactionInterceptor = new TransactionInterceptor();
        private Pointcut pointcut;
    }
    
    
    /*
    	DECOMPILATION REPORT
    
    	Decompiled from: D:\ChinaDevelopmentBankJBPM\workSpace\frame\webapp\WEB-INF\lib\spring-tx-3.0.3.RELEASE.jar
    	Total time: 151 ms
    	Jad reported messages/errors:
    	Exit status: 0
    	Caught exceptions:
    */

通过set方法我们就知道它需呀注入的属性：

setTransactionManager，setTransactionAttributes，setTransactionAttributeSource，setBeanFactory

对比上次对HibernateTemplete，我们可以简单的理解这个类进一步对transactionManager进行了管理。

\-----------------------------------------------------------------------------------------------------------------------------------------------------------------

事务的使用

context\_first.xml

对涉及事务的api要定义接口和实现类。

FirstDao

package org.first.dao;
    
    import java.util.List;
    
    public interface FirstDao {
    	
    	public List queryUsers(String realName);
    
    }

FirstDaoImpl

package org.first.dao.impl;
    
    import java.util.List;
    
    import org.base.MyHibernateDao;
    import org.first.dao.FirstDao;
    
    public class FirstDaoImpl extends MyHibernateDao implements FirstDao{
    	
    	public List queryUsers(String realName){
    		List list=null;
    		if(realName==null||realName.trim().equals("")){
    			System.out.println("参数realName为空，查询所有值。");
    			String hql="select u from LsyUser u ";
    			list=this.queryListHql(hql);
    		}else{
    			String hql="select u from LsyUser u where u.real_name like '%"+realName.trim()+"%'";
    			list=this.queryListHql(hql);
    		}
    		return list;
    	}
    }

然后再spring的配置文件中，如上，把接口类在spring中注册一个bean，class是：parent="transactionProxyTemplate"。

配置属性proxyInterfaces（接口类），target（接口的实现类）。

而接口的实现类需要注入sessionFactory。

上面的文件这样写更清楚：

再说些废话，上面用到了<bean id="firstDao" parent="transactionProxyTemplate">

这个parent简单说就是继承，如果你再配置一些属性，这些属性就会覆盖默认的属性值。

这样配置：

<bean id="transactionProxyTemplate" class="org.springframework.transaction.interceptor.TransactionProxyFactoryBean" abstract="true">
    		<property name="transactionManager" ref="transactionManager"/>
    		<property name="transactionAttributes">
    			<props>
    				<prop key="query*">PROPAGATION_REQUIRED</prop>
    				<prop key="*">PROPAGATION_REQUIRED</prop>
    			</props>
    		</property>
    	</bean>
    <bean id="firstDao" parent="transactionProxyTemplate">
    		<property name="target" ref="firstDaoTarget" />
    		<property name="proxyInterfaces">
    			<value> org.first.dao.FirstDao</value>
    		</property>
    	</bean>

相当于：

<bean id="firstDao" class="org.springframework.transaction.interceptor.TransactionProxyFactoryBean" abstract="true">
    		<property name="transactionManager" ref="transactionManager"/>
    		<property name="transactionAttributes">
    			<props>
    				<prop key="query*">PROPAGATION_REQUIRED</prop>
    				<prop key="*">PROPAGATION_REQUIRED</prop>
    			</props>
    		</property>
    		<property name="target" ref="firstDaoTarget" />
    		<property name="proxyInterfaces">
    			<value> org.first.dao.FirstDao</value>
    		</property>
    	</bean>

简单理解成继承就可以了，使用parent的好处也就是继承的好处，不用每个bean都去配置属性transactionManager，transactionAttributes。

有了继承，只需要配置一次即可。

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关于spring事务有哪几种方式，有篇文章介绍的很好。

[Spring事务配置的五种方式][Spring] http://www.blogjava.net/robbie/archive/2009/04/05/264003.html

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[Spring]: http://www.blogjava.net/robbie/archive/2009/04/05/264003.html