Spring的事务控制-基于xml方式

介绍：该程序模拟了转账操作，即Jone减少500元，tom增加500元

1.导入坐标

<dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.13</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context</artifactId>
      <version>5.2.9.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.aspectj</groupId>
      <artifactId>aspectjweaver</artifactId>
      <version>1.8.13</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-jdbc</artifactId>
      <version>5.0.9.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-tx</artifactId>
      <version>5.0.9.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-test</artifactId>
      <version>5.0.9.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>c3p0</groupId>
      <artifactId>c3p0</artifactId>
      <version>0.9.1</version>
    </dependency>
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>8.0.19</version>
    </dependency>

2.创建Account实体类

public class Account {
    private String name;
    private String money;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getMoney() {
        return money;
    }

    public void setMoney(String money) {
        this.money = money;
    }
}

3.创建AccountDao接口以及实现类AccountDaoImpl；

public interface AccountDao {
    public void out(String outMan,double money);
    public void in(String inMan,double money);
}

public class AccountDaoImpl implements AccountDao {

    private JdbcTemplate template;


    public void setTemplate(JdbcTemplate template) {
        this.template = template;
    }

    @Override
    public void out(String outMan, double money) {
        template.update("update account set money=money-? where name=?",money,outMan);
    }

    @Override
    public void in(String inMan, double money) {
        template.update("update account set money=money+? where name=?",money,inMan);
    }
}

4.创建AccountService接口以及AccountServiceImpl实现类

public interface AccountService {
    public void transfer(String outMan,String inMan,double money);
}

public class AccountServiceImpl implements AccountService {

    private AccountDao accountDao;

    public void setAccountDao(AccountDao accountDao) {
        this.accountDao = accountDao;
    }

    @Override
    public void transfer(String outMan, String inMan,double money) {
        accountDao.out(outMan,money);
        accountDao.in(inMan,money);
    }

}

5.编写spring配置文件（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"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
<!--将AccountDao注入到spring容器-->
    <bean id="accountDao" class="com.hao.dao.impl.AccountDaoImpl">
        <property name="template" ref="jdbcTemplate"/>
    </bean>
<!--将AccountService注入到spring容器-->
    <bean id="accountService" class="com.hao.service.impl.AccountServiceImpl">
        <property name="accountDao" ref="accountDao"/>
    </bean>
<!--    配置数据源-->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="com.mysql.cj.jdbc.Driver"/>
        <property name="jdbcUrl" value="jdbc:mysql://localhost:3306/test?serverTimezone=UTC"/>
        <property name="user" value="root"/>
        <property name="password" value="hao20001010"/>
    </bean>
<!--    将模板对象注入到spring容器-->
    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dataSource"/>
    </bean>
</beans>

6.数据库表的创建

7.测试

public class AccountController {
    public static void main(String[] args) {
        ApplicationContext context=new ClassPathXmlApplicationContext("applicationContext.xml");
        AccountService service= context.getBean(AccountService.class);
        service.transfer("Jone","tom",500);
    }
}

结果：

---

将Jone和tom的钱修改为5000元

当我们在业务方法transfer中手动加入错误代码，让其报错

再此运行，我们发现控制台报错，接着查看数据库中的数据

出现这样的原因就是，当程序执行完accountDao.out(outMan,money)时，Jone的钱减少500，但是当执行下一步int i=1/0时，程序出现错误，然后就不再执行下一步功能了，所有出现了这样的情况；

这样的问题该怎么解决呢？
利用aop思想，将事务提取出来交给spring管理，在程序运行时，与方法进行切入即可；这样可以保证如果程序运行时出现错误，则双方的金额都不会改变

<?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 https://www.springframework.org/schema/aop/spring-aop.xsd">
<!--将AccountDao注入到spring容器-->
    <bean id="accountDao" class="com.hao.dao.impl.AccountDaoImpl">
        <property name="template" ref="jdbcTemplate"/>
    </bean>
<!--将AccountService注入到spring容器,目标对象，内部的方法就是切点-->
    <bean id="accountService" class="com.hao.service.impl.AccountServiceImpl">
        <property name="accountDao" ref="accountDao"/>
    </bean>

<!--    配置平台事务管理器,当前的DataSourceTransactionManager是jdbc、mybatis技术，如果以后使用了其他技术，则此处需要修改-->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"/>
    </bean>
<!--    通知，事务的增强,引入事务的命名空间tx-->
    <tx:advice id="tx" transaction-manager="transactionManager">
    <!--设置属性信息的 -->
        <tx:attributes>
            <tx:method name="transfer" isolation="REPEATABLE_READ" propagation="REQUIRED" read-only="false"/>
            <tx:method name="*"/>
        </tx:attributes>
    </tx:advice>
<!--    配置aop织入，advice-ref引入通知(唯一标识id)   pointcut(切入的方法）-->
    <aop:config>
        <aop:advisor advice-ref="tx" pointcut="execution(* com.hao.service.impl.*.*(..))"/>
    </aop:config>


<!--    配置数据源-->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="com.mysql.cj.jdbc.Driver"/>
        <property name="jdbcUrl" value="jdbc:mysql://localhost:3306/test?serverTimezone=UTC"/>
        <property name="user" value="root"/>
        <property name="password" value="hao20001010"/>
    </bean>
<!--    将模板对象注入到spring容器-->
    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dataSource"/>
    </bean>
</beans>

将金额修改为5000元

再次运行：

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

<tx:method name="transfer" isolation="REPEATABLE_READ" propagation="REQUIRED" read-only="false"/>

1.name：切入点方法名称
2.isolation：事务的隔离级别
3.propogation：事务的传播行为
4.timeout：超时时间
5.read-only：是否只读