Spring对事务的支持（三）

第一节：事务简介
满足一下四个条件：
第一：原子性；
第二：一致性；
第三：隔离性；
第四：持久性；

第二节：编程式事务管理
Spring 提供的事务模版类：org.springframework.transaction.support.TransactionTemplate
事务管理器：org.springframework.jdbc.datasource.DataSourceTransactionManager

管理事务的代码切入到业务代码中，不好。

<?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:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/aop
        http://www.springframework.org/schema/aop/spring-aop.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd">
        
    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
        <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>
    
    <!-- jdbc事务管理器 -->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"></property>
    </bean>
    
    <bean id="transactionTemplate" class="org.springframework.transaction.support.TransactionTemplate">
        <property name="transactionManager" ref="transactionManager"></property>
    </bean>
     
    <context:property-placeholder location="jdbc.properties"/>
    
    <bean id="namedParameterJdbcTemplate" class="org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate">
        <constructor-arg ref="dataSource"></constructor-arg>
    </bean>
    
    
    <bean id="bankDao" class="com.java1234.dao.impl.BankDaoImpl">
        <property name="namedParameterJdbcTemplate" ref="namedParameterJdbcTemplate"></property>
    </bean> 
    
    <bean id="bankService" class="com.java1234.service.impl.BankServiceImpl">
        <property name="bankDao" ref="bankDao"></property>
        <property name="transactionTemplate" ref="transactionTemplate"></property>
    </bean> 
    
</beans>

public class BankServiceImpl implements BankService{

    private BankDao bankDao;
    
    private TransactionTemplate transactionTemplate;
    
    public void setBankDao(BankDao bankDao) {
        this.bankDao = bankDao;
    }
    
    


    public void setTransactionTemplate(TransactionTemplate transactionTemplate) {
        this.transactionTemplate = transactionTemplate;
    }




    @Override
    public void transferAccounts(final int count, final int userIdA, final int userIdB) {
        // TODO Auto-generated method stub
        transactionTemplate.execute(new TransactionCallbackWithoutResult() {
            
            @Override
            protected void doInTransactionWithoutResult(TransactionStatus arg0) {
                // TODO Auto-generated method stub
                bankDao.outMoney(count, userIdA);
                bankDao.inMoney(count, userIdB);                
            }
        });
    }

}


=========================================

public class T {

    private ApplicationContext ac;

    @Before
    public void setUp() throws Exception {
        ac=new ClassPathXmlApplicationContext("beans.xml");
    }

    @Test
    public void transferAccounts() {
        BankService bankService=(BankService)ac.getBean("bankService");
        bankService.transferAccounts(50, 1, 2);
    }
    
    

}

==============================================

public class BankDaoImpl implements BankDao{

    private NamedParameterJdbcTemplate namedParameterJdbcTemplate;
    
    
    public void setNamedParameterJdbcTemplate(
            NamedParameterJdbcTemplate namedParameterJdbcTemplate) {
        this.namedParameterJdbcTemplate = namedParameterJdbcTemplate;
    }
    
    @Override
    public void inMoney(int money, int userId) {
        // TODO Auto-generated method stub
        String sql="update t_count2 set count=count+:money where userId=:userId";
        MapSqlParameterSource sps=new MapSqlParameterSource();
        sps.addValue("money", money);
        sps.addValue("userId", userId);
        namedParameterJdbcTemplate.update(sql,sps);
    }

    @Override
    public void outMoney(int money, int userId) {
        // TODO Auto-generated method stub
        String sql="update t_count set count=count-:money where userId=:userId";
        MapSqlParameterSource sps=new MapSqlParameterSource();
        sps.addValue("money", money);
        sps.addValue("userId", userId);
        namedParameterJdbcTemplate.update(sql,sps);
    }

}

 

第三节：声明式事务管理
1，使用 XML 配置声明式事务；（一般用这种，项目较大，只要在xml文件中统一配置好，下面的要在每个serviceImpl写注解@Transactional，很麻烦）

加入事务命名空间和其地址：xmlns:tx="http://www.springframework.org/schema/tx"   http://www.springframework.org/schema/tx
        http://www.springframework.org/schema/tx/spring-tx.xsd

编程式事务模板可以删除，只剩下业务代码。

<?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:context="http://www.springframework.org/schema/context"
    xmlns:tx="http://www.springframework.org/schema/tx"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/aop
        http://www.springframework.org/schema/aop/spring-aop.xsd
        http://www.springframework.org/schema/tx
        http://www.springframework.org/schema/tx/spring-tx.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd">
        
    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
        <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>
    
    <!-- jdbc事务管理器 -->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"></property>
    </bean>
    
    <!-- 配置事务通知 ，通过配置 Propagation，来定义事务传播行为；PROPAGATION_REQUIRED--支持当前事务，如果当前没有事务，就新建一个事务。这是最常见的选择。-->
    <tx:advice id="txAdvice" transaction-manager="transactionManager">
        <tx:attributes>  
            <tx:method name="insert*" propagation="REQUIRED" />  
            <tx:method name="update*" propagation="REQUIRED" />  
            <tx:method name="edit*" propagation="REQUIRED" />  
            <tx:method name="save*" propagation="REQUIRED" />  
            <tx:method name="add*" propagation="REQUIRED" />  
            <tx:method name="new*" propagation="REQUIRED" />  
            <tx:method name="set*" propagation="REQUIRED" />  
            <tx:method name="remove*" propagation="REQUIRED" />  
            <tx:method name="delete*" propagation="REQUIRED" />  
            <tx:method name="change*" propagation="REQUIRED" />  
            <tx:method name="get*" propagation="REQUIRED" read-only="true" />  
            <tx:method name="find*" propagation="REQUIRED" read-only="true" />  
            <tx:method name="load*" propagation="REQUIRED" read-only="true" />  
            <tx:method name="*" propagation="REQUIRED" read-only="true" />  
        </tx:attributes>  
    </tx:advice>
    
    <!-- 配置事务切面 -->
    <aop:config>
        <!-- 配置切点 -->
        <aop:pointcut id="serviceMethod" expression="execution(* com.java1234.service.*.*(..))" />
        <!-- 配置事务通知 -->
        <aop:advisor advice-ref="txAdvice" pointcut-ref="serviceMethod"/>
    </aop:config>
    
 
     
    <context:property-placeholder location="jdbc.properties"/>
    
    <bean id="namedParameterJdbcTemplate" class="org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate">
        <constructor-arg ref="dataSource"></constructor-arg>
    </bean>
    
    
    <bean id="bankDao" class="com.java1234.dao.impl.BankDaoImpl">
        <property name="namedParameterJdbcTemplate" ref="namedParameterJdbcTemplate"></property>
    </bean> 
    
    <bean id="bankService" class="com.java1234.service.impl.BankServiceImpl">
        <property name="bankDao" ref="bankDao"></property>
    </bean> 
    
</beans>

public class BankServiceImpl implements BankService{

    private BankDao bankDao;
    
    public void setBankDao(BankDao bankDao) {
        this.bankDao = bankDao;
    }
    

    @Override
    public void transferAccounts(int count, int userIdA, int userIdB) {
        // TODO Auto-generated method stub
                // TODO Auto-generated method stub
        bankDao.outMoney(count, userIdA);
        bankDao.inMoney(count, userIdB);                
    }

}

2，使用注解配置声明式事务；

xml中需要声明开启注解<tx:annotation-driven transaction-manager="transactionManager"/>，需在serviceImpl写注解@Transactional （可配置在方法上或者类上）

<?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:context="http://www.springframework.org/schema/context"
    xmlns:tx="http://www.springframework.org/schema/tx"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/aop
        http://www.springframework.org/schema/aop/spring-aop.xsd
        http://www.springframework.org/schema/tx
        http://www.springframework.org/schema/tx/spring-tx.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd">
        
    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
        <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>
    
    <!-- jdbc事务管理器 -->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"></property>
    </bean>
    
   <!--  注解配置声明式事务 -->
    <tx:annotation-driven transaction-manager="transactionManager"/>
     
    <context:property-placeholder location="jdbc.properties"/>
    
    <bean id="namedParameterJdbcTemplate" class="org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate">
        <constructor-arg ref="dataSource"></constructor-arg>
    </bean>
    
    
    <bean id="bankDao" class="com.java1234.dao.impl.BankDaoImpl">
        <property name="namedParameterJdbcTemplate" ref="namedParameterJdbcTemplate"></property>
    </bean> 
    
    <bean id="bankService" class="com.java1234.service.impl.BankServiceImpl">
        <property name="bankDao" ref="bankDao"></property>
    </bean> 
    
</beans>

@Transactional
public class BankServiceImpl implements BankService{

    private BankDao bankDao;
    
    public void setBankDao(BankDao bankDao) {
        this.bankDao = bankDao;
    }
    

    @Override
    public void transferAccounts(int count, int userIdA, int userIdB) {
        // TODO Auto-generated method stub
                // TODO Auto-generated method stub
        bankDao.outMoney(count, userIdA);
        bankDao.inMoney(count, userIdB);                
    }

}

 

第四节：事务传播行为
事务传播行为：Spring 中，当一个 service 方法调用另外一个 service 方法的时候，因为每个 service 方法都有事
务，这时候就出现了事务的嵌套；由此，就产生了事务传播行为；
在 Spring 中，通过配置 Propagation，来定义事务传播行为；
PROPAGATION_REQUIRED--支持当前事务，如果当前没有事务，就新建一个事务。这是最常见的选择。
PROPAGATION_SUPPORTS--支持当前事务，如果当前没有事务，就以非事务方式执行。
PROPAGATION_MANDATORY--支持当前事务，如果当前没有事务，就抛出异常。
PROPAGATION_REQUIRES_NEW--新建事务，如果当前存在事务，把当前事务挂起。
PROPAGATION_NOT_SUPPORTED--以非事务方式执行操作，如果当前存在事务，就把当前事务挂起。
PROPAGATION_NEVER--以非事务方式执行，如果当前存在事务，则抛出异常。