Spring中的声明式事务

Spring中的声明式事务

• 要么都成功，要么都失败
• 开发中很重要，涉及数据一致性

事务的ACID原则：

• 原子性(Atomicity)
• 一致性(Consistency)
• 隔离性(Isolation)
• 持久性(Durability)

UserMapperImpl

package com.harris.mapper;

import com.harris.pojo.User;
import org.mybatis.spring.support.SqlSessionDaoSupport;

import java.util.List;


public class UserMapperImpl extends SqlSessionDaoSupport implements UserMapper{


    @Override
    public List<User> selectUser() {
        User user = new User(6, "小王", "12313213");
        UserMapper mapper = getSqlSession().getMapper(UserMapper.class);
        mapper.addUser(user);
        mapper.deleteUser(6);
        return mapper.selectUser();
    }

    @Override
    public int addUser(User user) {
        return getSqlSession().getMapper(UserMapper.class).addUser(user);
    }

    @Override
    public int deleteUser(int id) {
        return getSqlSession().getMapper(UserMapper.class).deleteUser(id);
    }
}

spring-dao.xml的配置

<?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.xsd
       http://www.springframework.org/schema/aop
       https://www.springframework.org/schema/aop/spring-aop.xsd
        http://www.springframework.org/schema/tx
       http://www.springframework.org/schema/tx/spring-tx.xsd
        ">
    <!-- dataSource -->
    <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=false&amp;userUnicode=true&amp;characterEncoding=UTF-8&amp;serverTimezone=UTC"/>
        <property name="username" value="root"/>
        <property name="password" value="Hh013227369688"/>
    </bean>
    <!-- sqlSessionFactory-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <!-- 绑定mybatis 配置文件-->
        <property name="configLocation" value="classpath:mybatis-config.xml"/>
        <property name="mapperLocations" value="classpath:com/harris/mapper/*.xml"/>
    </bean>
    <bean id="usermapper" class="com.harris.mapper.UserMapperImpl">
        <property name="sqlSessionFactory"  ref="sqlSessionFactory"/>
    </bean>
    <!-- 配置声明式事务-->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"/>
    </bean>
    <!-- 配置事务通知 -->
    <tx:advice id="txAdvice" transaction-manager="transactionManager">
        <!-- 事务的属性  方法 的 传播属性propagation-->
        <tx:attributes>
            <tx:method name="add" propagation="REQUIRED"/>
            <tx:method name="delete" propagation="REQUIRED"/>
            <tx:method name="update" propagation="REQUIRED"/>
            <tx:method name="select" read-only="true"/>
            <tx:method name="*" propagation="REQUIRED"/>
        </tx:attributes>
    </tx:advice>
    <!--AOP实现事务的织入 -->

    <!-- 配置事务切入-->
    <aop:config>
        <aop:pointcut id="txPointCut" expression="execution(* com.harris.mapper.*.*(..))"/>
        <aop:advisor advice-ref="txAdvice" pointcut-ref="txPointCut"/>
    </aop:config>
</beans>

Test

import com.harris.mapper.UserMapper;
import com.harris.pojo.User;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class MyTest {
    @Test
    public void Test1(){
       ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
        UserMapper usermapper = context.getBean("usermapper", UserMapper.class);
        for (User user : usermapper.selectUser()) {
            System.out.println(user);
        }
    }
}

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这样若delete方法有问题，则add事务不会成功，保证了事务的ACID原则。