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Spring入门(四)之AOP事物

Spring入门(四)之AOP事物

作者: 穿梭在围城 | 来源:发表于2018-12-03 21:31 被阅读0次

Spring入门之AOP事物的实现

一、原理

image.png

因为在业务层中我们会有很多业务方法,比如银行转账业务(从目标:from中扣钱,向目的地:target增加)都需要事物的介入,然而Spring的AOP技术出现后,我们可以很容易的使用环绕通知来解决这一难题(很多业务都需要事物管理,开发者手动添加事物很累!)。

二、实现(xml)

image.png

这里我用模拟银行转账的小程序来实现事物管理

image.png
package cn.zw.tx;

/**
 * 
 * @ClassName:  BankDao   
 * @Description:TODO(模拟银行转账接口)   
 * @date:   2018年12月3日 下午8:21:26   
 */
public interface BankDao {
    
    /**
     * 
     * @Title:  BankDao   
     * @Description:转入
     * @param:  @param target 目标账户
     * @param:  @param money  金额
     * @throws
     */
    void increaseMoney(int target , double money);
    
    /**
     * 
     * @Title:  BankDao   
     * @Description:转出
     * @param:  @param target 目标账户
     * @param:  @param money  金额
     * @throws
     */
    void decreaseMoney(int target ,double money);
}

package cn.zw.tx;

import org.springframework.jdbc.core.support.JdbcDaoSupport;


public class BankDaoImpl extends JdbcDaoSupport implements BankDao {

    
    /**
     * 
     * <p>Title: increaseMoney</p>   
     * <p>Description:转入 </p>   
     * @param target 目标账户
     * @param money  转入金额 
     * @see cn.zw.tx.BankDao#increaseMoney(int, double)
     */
    @Override
    public void increaseMoney(int target, double money) {
        String sql = "update user set money = money + ? where id = ?";
        getJdbcTemplate().update(sql,money,target);
    }
    
    /**
     * 
     * <p>Title: decreaseMoney</p>   
     * <p>Description:转出 </p>   
     * @param target 目标账户
     * @param money  转出金额
     * @see cn.zw.tx.BankDao#decreaseMoney(int, double)
     */
    @Override
    public void decreaseMoney(int target, double money) {
        String sql = "update user set money = money - ? where id = ?";
        getJdbcTemplate().update(sql,money,target);
    }

}

package cn.zw.tx;

/**
 * 
 * @ClassName:  BankService   
 * @Description: 转账的业务层  
 */
public interface BankService {
    
    /**
     * 
     * @Title:  BankService   
     * @Description:  转账业务 
     * @param:  @param from  从哪个账务转出
     * @param:  @param to    向哪个账户转入
     * @param:  @param money  转入金额
     * @throws
     */
    void transfer(int from ,int to,double money);
}

package cn.zw.tx;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class BankServiceImpl implements BankService {
    
    @Autowired
    private BankDao db;
    

    /**
     * 
     * <p>Title: transfer</p>
     * <p>Description: 转账业务 </p>
     * @param: from 从哪个账务转出
     * @param: to 向哪个账户转入
     * @param: money 转入金额
     * @see cn.zw.tx.BankService#transfer(int, int, double)
     */
    @Override
    public void transfer(int from, int to, double money) {
        db.decreaseMoney(from, money);
        
        db.increaseMoney(to, money);
    }

}

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://www.springframework.org/schema/beans" xmlns:p="http://www.springframework.org/schema/p"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:aop="http://www.springframework.org/schema/aop"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.2.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.2.xsd
        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.2.xsd">
    <context:property-placeholder location="classpath:c3p0.properties" />
    <context:component-scan base-package="cn.zw.tx"></context:component-scan>
    
    <bean name="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="user" value="${jdbc.user}"></property>
        <property name="driverClass" value="${jdbc.driverClass}"></property>
        <property name="jdbcUrl" value="${jdbc.jdbcUrl}"></property>
        <property name="password" value="${jdbc.password}"></property>
    </bean>
    
    <bean name="bankDaoImpl"  class="cn.zw.tx.BankDaoImpl">
        <property name="dataSource" ref="dataSource"></property>
    </bean>
    
    
</beans>

`

package cn.zw.tx;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:application-context8.xml")
public class DemoTest {

    @Autowired
    private BankService bs;
    
    
    @Test
    public void fun01(){
        bs.transfer(1, 2, 100D);
    }
    
    
}

image.png

向代码中加入了异常,模拟停电

image.png

执行结果

image.png

将代码进行改造

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://www.springframework.org/schema/beans"
    xmlns:p="http://www.springframework.org/schema/p"
    xmlns:context="http://www.springframework.org/schema/context"
    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-4.2.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.2.xsd
        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.2.xsd
        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.2.xsd">
    
    <context:property-placeholder location="classpath:c3p0.properties" />
    
    <context:component-scan base-package="cn.zw.tx"></context:component-scan>
    <!-- 配置数据库连接池 -->
    <bean name="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="user" value="${jdbc.user}"></property>
        <property name="driverClass" value="${jdbc.driverClass}"></property>
        <property name="jdbcUrl" value="${jdbc.jdbcUrl}"></property>
        <property name="password" value="${jdbc.password}"></property>
    </bean>
    
    <bean name="bankDaoImpl"  class="cn.zw.tx.BankDaoImpl">
        <property name="dataSource" ref="dataSource"></property>
    </bean>
    
    
    <!-- 数据库实务管理类 -->
    <bean name="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"></property>
    </bean>
    
    
    <!-- 定义通知 -->
    <tx:advice id="txAdvice" transaction-manager="transactionManager">
        <tx:attributes>
            <tx:method name="transfer" read-only="false" timeout="-1" propagation="REQUIRED" isolation="DEFAULT"/>
        </tx:attributes>
    </tx:advice>
    
    <!-- 织入 -->
    <aop:config>
        <aop:pointcut expression="execution(* cn.zw.tx.*ServiceImpl.*(..))" id="myPC"/>
        <aop:advisor advice-ref="txAdvice" pointcut-ref="myPC"/>
    </aop:config>
    
</beans>
image.png

搞定!

三、实现(注解)

`

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://www.springframework.org/schema/beans"
    xmlns:p="http://www.springframework.org/schema/p"
    xmlns:context="http://www.springframework.org/schema/context"
    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-4.2.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.2.xsd
        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.2.xsd
        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.2.xsd">
    
    <context:property-placeholder location="classpath:c3p0.properties" />
    
    <context:component-scan base-package="cn.zw.tx"></context:component-scan>
    <!-- 配置数据库连接池 -->
    <bean name="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="user" value="${jdbc.user}"></property>
        <property name="driverClass" value="${jdbc.driverClass}"></property>
        <property name="jdbcUrl" value="${jdbc.jdbcUrl}"></property>
        <property name="password" value="${jdbc.password}"></property>
    </bean>
    
    <bean name="bankDaoImpl"  class="cn.zw.tx.BankDaoImpl">
        <property name="dataSource" ref="dataSource"></property>
    </bean>
    
    
    <!-- 数据库实务管理类 -->
    <bean name="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"></property>
    </bean>
    
    <!-- 开启事物注解 -->
    <tx:annotation-driven transaction-manager="transactionManager"/>
    
    
</beans>
image.png

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