133、【JavaEE】【SSM】SSM 事务

1、SSM 事务

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.3.8</version>
        </dependency>

• src/main/resources/applicationContext.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"
       xsi:schemaLocation="http://www.springframework.org/schema/beans https://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd
       http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd">

    <context:component-scan base-package="com.yscyber.ssm.service"/>

    <!-- 引入 jdbc.properties -->
    <context:property-placeholder location="classpath:jdbc.properties"/>

    <!-- 配置数据源（交予 Spring 容器管理） -->
    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
        <property name="driverClassName" value="${jdbc_driver}"/>
        <property name="url" value="${jdbc_url}"/>
        <property name="username" value="${jdbc_username}"/>
        <property name="password" value="${jdbc_password}"/>
    </bean>

    <!--  配置 SqlSessionFactory  -->
    <!-- id 一般为 sqlSessionFactory -->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <property name="configLocation" value="classpath:mybatis.xml"/>
    </bean>

    <!-- 配置 Mapper 扫描 -->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.yscyber.ssm.repo"/>
    </bean>

    <!-- 事务注解扫描 -->
    <tx:annotation-driven/>
    <!-- 配置事务管理器 -->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"/>
    </bean>

</beans>

2、测试

CREATE TABLE xxx(
  id INT NOT NULL,
  name VARCHAR(3) NOT NULL
);

package com.yscyber.ssm.pojo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.ToString;

@NoArgsConstructor
@AllArgsConstructor
@Data
@ToString
public class MyObj {

    private Integer id;

    private String name;

}

package com.yscyber.ssm.repo;

import com.yscyber.ssm.pojo.MyObj;

import java.util.List;

public interface MyObjRepo {

    List<MyObj> listAllMyObjs();

    int insertMyObj(MyObj myObj);

}

package com.yscyber.ssm.service;

import com.yscyber.ssm.pojo.MyObj;

import java.util.List;

public interface MyObjService {

    List<MyObj> listAllObjs();

    /**
     * 测试 事务 专用方法，无实际意义
     */
    int insertTwoMyObjs(MyObj myObj1, MyObj myObj2);

}

package com.yscyber.ssm.service.impl;

import com.yscyber.ssm.pojo.MyObj;
import com.yscyber.ssm.repo.MyObjRepo;
import com.yscyber.ssm.service.MyObjService;

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

import java.util.List;

@Service
public class MyObjServiceImpl implements MyObjService {

    @Autowired
    private MyObjRepo myObjRepo;

    @Override
    public List<MyObj> listAllObjs() {
        return myObjRepo.listAllMyObjs();
    }

    @Override
    @Transactional
    public int insertTwoMyObjs(MyObj myObj1, MyObj myObj2) {
        myObjRepo.insertMyObj(myObj1);
        int i  = 1/0; // 故意设置异常
        return myObjRepo.insertMyObj(myObj2);
    }

}

package com.yscyber.ssm;

import com.yscyber.ssm.pojo.MyObj;
import com.yscyber.ssm.service.MyObjService;

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(locations = {"classpath:applicationContext.xml"})
public class MyTest {

    @Autowired
    private MyObjService myObjService;

    @Test
    public void test1() {
        MyObj myObj1 = new MyObj(99, "PRC");
        MyObj myObj2 = new MyObj(98, "USA");

        // 如果事务有效，两条数据都无法插入至数据库
        myObjService.insertTwoMyObjs(myObj1, myObj2);
    }

}