spring事务管理之二：声明式事务管理：使用代理方式

た入场券 2022-04-08 14:21 332阅读 0赞

spring声明式事务管理，分为三种方式,分别是：

1、使用代理类TransactionProxyFactoryBean的方式

2、使用aspectj+xml配置的方式

3、使用事务注解的方式

其中后面两种是比较常用的，使用xml和注解的方式。

这里介绍使用代理类TransactionProxyFactoryBean的方式：

pom.xml

<dependencies>
        <dependency>
          	<groupId>junit</groupId>
          	<artifactId>junit</artifactId>
          	<version>4.12</version>
          	<scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.aspectj</groupId>
        	<artifactId>aspectjweaver</artifactId>
        	<version>1.8.13</version>
        </dependency>
        <dependency>
        	<groupId>org.springframework</groupId>
        	<artifactId>spring-context-support</artifactId>
        	<version>4.3.4.RELEASE</version>
        </dependency>
        <dependency>
        	<groupId>org.springframework</groupId>
        	<artifactId>spring-tx</artifactId>
        	<version>4.3.4.RELEASE</version>
        </dependency>
        <dependency>
        	<groupId>org.springframework</groupId>
        	<artifactId>spring-jdbc</artifactId>
        	<version>4.3.4.RELEASE</version>
        </dependency>
        <dependency>
        	<groupId>org.springframework</groupId>
        	<artifactId>spring-test</artifactId>
        	<version>4.3.4.RELEASE</version>
        </dependency>
        <dependency>
        	<groupId>mysql</groupId>
        	<artifactId>mysql-connector-java</artifactId>
        	<version>5.1.38</version>
        </dependency>
      </dependencies>

jdbc.properties

jdbc.driverClassName=com.mysql.jdbc.Driver
    jdbc.url=jdbc:mysql:///shop?useUnicode=true&useSSL=false
    jdbc.username=hadoop
    jdbc.password=hadoop

spring.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:context="http://www.springframework.org/schema/context"
    	xmlns:tx="http://www.springframework.org/schema/tx"
    	xmlns:aop="http://www.springframework.org/schema/aop"
    	xsi:schemaLocation="http://www.springframework.org/schema/beans 
            http://www.springframework.org/schema/beans/spring-beans-4.3.xsd
    		http://www.springframework.org/schema/context 
            http://www.springframework.org/schema/context/spring-context-4.3.xsd
    		http://www.springframework.org/schema/aop
            http://www.springframework.org/schema/aop/spring-aop-4.3.xsd
    		http://www.springframework.org/schema/tx 
            http://www.springframework.org/schema/tx/spring-tx-4.3.xsd">
        <context:property-placeholder location="classpath:jdbc.properties"/>
        <bean id="dataSource" 
           class="org.springframework.jdbc.datasource.DriverManagerDataSource">
           <property name="driverClassName" value="${jdbc.driverClassName}"/>
           <property name="url" value="${jdbc.url}"/>
           <property name="username" value="${jdbc.username}"/>
           <property name="password" value="${jdbc.password}"/>
        </bean>
        <bean id="accountDao" class="com.xxx.springtransaction.dao.impl.AccountDaoImpl">
        	<property name="dataSource" ref="dataSource"/>
        </bean>
        <bean id="accountService" 
            class="com.xxx.springtransaction.service.impl.AccountServiceImpl">
            <property name="accountDao" ref="accountDao" />
        </bean>
        <bean id="transactionManager" 
            class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
            <property name="dataSource" ref="dataSource" />
        </bean>
        
        <bean id="accountServiceProxy" 
            class="org.springframework.transaction.interceptor.TransactionProxyFactoryBean">
        	<property name="transactionManager" ref="transactionManager" />
        	<property name="target" ref="accountService" />
        	<property name="transactionAttributes">
        		<props>
        			<prop key="transfer">PROPAGATION_REQUIRED</prop>
        		</props>
        	</property>
        </bean>
    </beans>

AccountDao.java

package com.xxx.springtransaction.dao;
    
    public interface AccountDao {
    	public void transferIn(String id,Double money);
    	public void transferOut(String id,Double money);
    	public Double findById(String id);
    }

AccountDaoImpl.java

package com.xxx.springtransaction.dao.impl;
    import org.springframework.jdbc.core.support.JdbcDaoSupport;
    import com.xxx.springtransaction.dao.AccountDao;
    public class AccountDaoImpl extends JdbcDaoSupport implements AccountDao {	
    
    	@Override
    	public void transferIn(String id, Double money) {
    		String sql = "update account set money = money + ? where id = ?";
    		getJdbcTemplate().update(sql, money,id);
    	}
    
    	@Override
    	public void transferOut(String id, Double money) {
    		String sql = "update account set money = money - ? where id = ?";
    		getJdbcTemplate().update(sql, money,id);
    	}
    	
    	@Override
    	public Double findById(String id){
    		return null;
    	}
    
    }

AccountService.java

package com.xxx.springtransaction.service;
    
    public interface AccountService {
    	public void transfer(String out,String in,Double money);
    	public Double findById(String id);
    }

AccountServiceImpl.java

package com.xxx.springtransaction.service.impl;
    import com.xxx.springtransaction.dao.AccountDao;
    import com.xxx.springtransaction.service.AccountService;
    public class AccountServiceImpl implements AccountService {
    	
    	private AccountDao accountDao;
    	public void setAccountDao(AccountDao accountDao) {
    		this.accountDao = accountDao;
    	}
    
    	@Override
    	public void transfer(String out, String in, Double money) {	
    		accountDao.transferOut(out, money);
    		int i = 1/0;
    		System.out.println(i);
    		accountDao.transferIn(in, money);
    	}
    
    	
    	@Override
    	public Double findById(String id){
    		return accountDao.findById(id);
    	}
    
    }

单元测试类：SpringTransactionTest.java

package com.xxx.springtransaction;
    import javax.annotation.Resource;
    import org.junit.Test;
    import org.junit.runner.RunWith;
    import org.springframework.test.context.ContextConfiguration;
    import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
    import com.xxx.springtransaction.service.AccountService;
    
    @RunWith(SpringJUnit4ClassRunner.class)
    @ContextConfiguration("classpath:spring.xml")
    public class SpringTransactionTest {
    	@Resource(name="accountServiceProxy")
    	private AccountService accountService;
    	
    	@Test
    	public void demo1(){
    		accountService.transfer("1", "2", 200d);
    	}
    }

代理方式事务管理的重点在于xml配置里面，需要为target为accountService的目标类配置事务属性。

![20181220143903289.png][]

在调用业务层方法时，需要引入的对象已经不是accountService了，而是变成了代理类accountServiceProxy。

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlaW5pZmk_size_16_color_FFFFFF_t_70][]

测试事务生效的方法：

1、默认不使用事务，单元测试方法中还是使用@Resource(name="accountService")，并且注释掉业务层方法的异常代码：

int i = 1/0;  
System.out.println(i);

aaa向bbb转账200元成功，aaa的账户变为800，bbb的账户变为1200。

2、去掉业务层的异常代码注释，这时候不使用事务，aaa转账bbb200元，aaa的账户变为600元，但是因为异常，bbb的账户并不会增加200元，最终aaa账户600，bbb的账户1200元，钱转丢了。

3、使用事务，单元测试类中@Resource(name="accountServiceProxy")，并且去掉业务层异常代码的注释。aaa再次给bbb转账，这时候因为异常，而且使用了事务。aaa的账户不会减少200元，而且bbb的账户也不会增加200元。在测试2的基础上aaa的账户还是600元，bbb的账户还是1200元。

[20181220143903289.png]: /images/20220404/ec93fcc1c5bc428499e6fb5b39e1ab37.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2ZlaW5pZmk_size_16_color_FFFFFF_t_70]: /images/20220404/46b24d9cbc8e4f35b21ee33be59f0650.png