spring-申明式事务

一.什么是事务

事务的原则是：处于事务中的sql代码块会保持一致状态，即要么都能改变数据库，要么都不能改变数据库

ACID原则：

• 原子性
• 一致性
• 隔离性

1. 多个业务可能操作同一个业务，防止数据损坏

• 持久性

1. 事务一旦提交，无论体系发生什么问题，结果都不会受影响，将被持久化到存储器

二.spring中的事务管理

• 声明式事务：AOP（不会改动源代码，只需要再spring容器中注入）
• 编程式事务：需要在代码中，完成事务处理

测试环境：

接口：

package top.lostyou.dao;

import org.apache.ibatis.annotations.Param;
import top.lostyou.pojo.User;

import java.util.List;
import java.util.Map;

public interface UserMapper {
    List<User> selectUser();
    int insertUser(User user);
    int deleteUser(@Param("id") int id);

}

sql语句：

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="top.lostyou.dao.UserMapper">
    <select id="selectUser" resultType="user">
        SELECT * FROM mybatis.user
    </select>
    <insert id="insertUser" parameterType="user">
        INSERT INTO mybatis.user(id, name, pwd) VALUES (#{id},#{name},#{pwd})
    </insert>
    <delete id="deleteUser" parameterType="int">
        DELETE FROM mybatis.user WHERE id=#{id}
    </delete>
</mapper>

spring中配置事务：

<?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: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.xsd

        http://www.springframework.org/schema/tx
    http://www.springframework.org/schema/tx/spring-tx.xsd
    http://www.springframework.org/schema/aop
     http://www.springframework.org/schema/aop/spring-aop.xsd">
    <bean id="dateSources" 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;uesUnicode=true&amp;characterEncoding=UTF-8"/>
        <property name="username" value="root"/>
        <property name="password" value="123456"/>
    </bean>
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dateSources"/>
        <property name="configLocation" value="classpath:mybatis.xml"/>
        <property name="mapperLocations" value="classpath:top/lostyou/dao/*.xml"/>
    </bean>

    <!--配置声明式事务：也可以叫开启事务-->
    <bean id="transactionManger" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dateSources"/>
    </bean>
    <!--结合AOP实现事务植入-->
    <!--配置事务通知-->
    <tx:advice id="tx" transaction-manager="transactionManger">
        <!--配置给那些方法实现事务-->
        <tx:attributes>
            <tx:method name="insertUser"/>
            <tx:method name="deleteUser"/>
            <tx:method name="*"/>
        </tx:attributes>
    </tx:advice>
    <!--配置事务切入-->
    <aop:config>
        <aop:pointcut id="poincut" expression="execution(* top.lostyou.dao.*.*(..))"/>
        <aop:advisor advice-ref="tx" pointcut-ref="poincut"/>
    </aop:config>
</beans>

实现类：

package top.lostyou.dao;

import org.mybatis.spring.support.SqlSessionDaoSupport;
import top.lostyou.pojo.User;

import java.util.List;
import java.util.Map;

public class UserImp extends SqlSessionDaoSupport implements UserMapper {

    public List<User> selectUser() {
        User user = new User(6, "mmmmm", "321654");
        int id = 5;
        insertUser(user);
        deleteUser(id);
        return getSqlSession().getMapper(UserMapper.class).selectUser();
    }

    public int insertUser(User user) {
        return getSqlSession().getMapper(UserMapper.class).insertUser(user);
    }

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

测试类：

import org.springframework.context.support.ClassPathXmlApplicationContext;
import top.lostyou.dao.UserMapper;
import top.lostyou.pojo.User;

import java.util.List;

public class myTest {
    public static void main(String[] args) {
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("User.xml");
        UserMapper userImp = context.getBean("userImp", UserMapper.class);
        List<User> users = userImp.selectUser();
        for (User user : users) {
            System.out.println(user);
        }
    }
}