Spring的事务控制

Spring的事务控制

• ​​1 基于 XML 的声明式事务控制​​
• ​​2 基于注解的声明式事务控制​​

1 基于 XML 的声明式事务控制

​事务控制最常见的场景为银行的转账业务，要么同时成功，要么同时失败，这里搭建一两银行转账业务使用xml声明式事务控制。​

​1）环境所需pom.xml​

<packaging>war</packaging>

<dependencies>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context</artifactId>
        <version>5.0.5.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.aspectj</groupId>
        <artifactId>aspectjweaver</artifactId>
        <version>1.8.4</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-jdbc</artifactId>
        <version>5.0.5.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-tx</artifactId>
        <version>5.0.5.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-test</artifactId>
        <version>5.0.5.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>c3p0</groupId>
        <artifactId>c3p0</artifactId>
        <version>0.9.1.1</version>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.25</version>
    </dependency>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.12</version>
    </dependency>
</dependencies>

​2）controller层：​

public class AccountController {
    public static void main(String[] args) {
        ApplicationContext app = new ClassPathXmlApplicationContext("applicationContext.xml");
        AccountService accountService = app.getBean(AccountService.class);
        accountService.transfer("张无忌", "郭靖", 500);
    }
}

​3）service层：​

public class AccountServiceImpl implements AccountService {

    private AccountDao accountDao;

    public void setAccountDao(AccountDao accountDao) {
        this.accountDao = accountDao;
    }
    
    public void transfer(String outMan, String inMan, double money) {   //转账业务
        accountDao.out(outMan, money);
        int a = 1 / 0;      //自造异常
        accountDao.in(inMan, money);
    }
}

​4）dao层：该层使用的是jdbcTemplate模板技术，如果使用其他技术后面applicationContext.xml中配置的平台事务管理器会有差别​

public class AccountDaoImpl implements AccountDao {

    private JdbcTemplate jdbcTemplate;
    public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
        this.jdbcTemplate = jdbcTemplate;
    }

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

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

​5）applicationContext.xml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 http://www.springframework.org/schema/aop/spring-aop.xsd
       http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd
">
    
    <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"/>
        <property name="user" value="root"/>
        <property name="password" value="LIFEILIN"/>
    </bean>

    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dataSource"/>
    </bean>

    <bean id="accountDao" class="lifeilin.dao.impl.AccountDaoImpl">
        <property name="jdbcTemplate" ref="jdbcTemplate"/>
    </bean>

    <!--    1 目标对象，内部方法就是切点-->
    <bean id="accountService" class="lifeilin.service.impl.AccountServiceImpl">
        <property name="accountDao" ref="accountDao"/>
    </bean>

    <!--    2 配置平台事务管理器-->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"></property>
    </bean>
    
    <!--    3 通知 事物的增强 引入命名空间tx-->
    <tx:advice id="txAdvice" transaction-manager="transactionManager">
        <tx:attributes>
            <tx:method name="*"/>
        </tx:attributes>
    </tx:advice>
    
    <!--    4 配置事务aop的织入-->
    <aop:config>
        <aop:advisor advice-ref="txAdvice" pointcut="execution(* lifeilin.service.impl.*.*(..))"></aop:advisor>
    </aop:config>
    
</beans>

2 基于注解的声明式事务控制

​① 使用 @Transactional 在需要进行事务控制的类或是方法上修饰，注解可用的属性同 xml 配置方式，例如隔离级别、传播行为等。
② 注解使用在类上，那么该类下的所有方法都使用同一套注解参数配置。
③ 使用在方法上，不同的方法可以采用不同的事务参数配置。
④ Xml配置文件中要开启事务的注解驱动<tx:annotation-driven />​

@Service("accountService")
@Transactional
public class AccountServiceImpl implements AccountService {

    @Autowired
    private AccountDao accountDao;

    @Transactional(isolation = Isolation.READ_COMMITTED ,propagation = Propagation.REQUIRED)
    public void transfer(String outMan, String inMan, double money) {   //转账业务
        accountDao.out(outMan, money);
        int a = 1 / 0;      //自造异常
        accountDao.in(inMan, money);
    }
}

<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"/>
    <property name="user" value="root"/>
    <property name="password" value="LIFEILIN"/>
</bean>

<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
    <property name="dataSource" ref="dataSource"/>
</bean>


<!--    2 配置平台事务管理器-->
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
    <property name="dataSource" ref="dataSource"></property>
</bean>

<!--    事务的注解驱动-->
<tx:annotation-driven transaction-manager="transactionManager"/>