02-Sping事务实现之声明式事务基于XML的实现方式

声明式事务之XML实现方式

开发步骤

第一步: 引入AOP相关的aspectj依赖

<dependency>
  <groupId>org.springframeworkgroupId>
  <artifactId>spring-aspectsartifactId>
  <version>6.0.0-M2version>
dependency>

第二步: 编写dao层接口及其实现类

public interface AccountDao {
    // 根据账号查询余额
    Account selectByActno(String actno);
    // 	更新账户信息
    int update(Account act);
}

@Repository("accountDao")
public class AccountDaoImpl implements AccountDao {
    @Resource(name = "jdbcTemplate")
    private JdbcTemplate jdbcTemplate;

    @Override
    public Account selectByActno(String actno) {
        String sql = "select actno, balance from t_act where actno = ?";
        Account account = jdbcTemplate.queryForObject(sql, new BeanPropertyRowMapper<>(Account.class), actno);
        return account;
    }

    @Override
    public int update(Account act) {
        String sql = "update t_act set balance = ? where actno = ?";
        int count = jdbcTemplate.update(sql, act.getBalance(), act.getActno());
        return count;
    }

}

第三步: 编写Service接口及其实现类,这里就不再使用@Transactional注解而是基于XML配置的方式实现声明式事务

@Service("accountService")
public class AccountServiceImpl implements AccountService {
    @Resource(name = "accountDao")
    private AccountDao accountDao;
    @Override
    public void transfer(String fromActno, String toActno, double money) {
        // 查询转出账户的余额是否充足
        Account fromAct = accountDao.selectByActno(fromActno);
        if (fromAct.getBalance() < money) {
            throw new RuntimeException("余额不足！！！");
        }
        // 余额充足
        Account toAct = accountDao.selectByActno(toActno);

        // 将内存中两个对象的余额先修改
        fromAct.setBalance(fromAct.getBalance() - money);
        toAct.setBalance(toAct.getBalance() + money);

        // 数据库更新
        int count = accountDao.update(fromAct);

        // 模拟异常
        String s = null;
        s.toString();

        count += accountDao.update(toAct);

        if(count != 2) {
            throw new RuntimeException("转账失败，联系银行！");
        }
    }

}

第四步: 在spring的配置文件中添加context,aop和tx的命名空间及其约束文件,然后配置数据源,JdbcTemplate,事务管理器,通知,切面

标签	描述
tx:advice	自定义一个事务通知
tx:method	配置事务通知作用的方法和事务的相关属性
advice-ref	引入自定义的通知

<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"
       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/context http://www.springframework.org/schema/context/spring-context.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">
    
    <context:component-scan base-package="com.powernode.bank"/>

    
    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
        <property name="driverClassName" value="com.mysql.cj.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql://localhost:3306/spring6"/>
        <property name="username" value="root"/>
        <property name="password" value="root"/>
    bean>

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

    
    <bean id="txManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"/>
    bean>

    
    <tx:advice id="txAdvice" transaction-manager="txManager">
        
        <tx:attributes>
            
            <tx:method name="transfer" propagation="REQUIRED" rollback-for="java.lang.Throwable"/>
            
            <tx:method name="save*" propagation="REQUIRED" rollback-for="java.lang.Throwable"/>
            <tx:method name="delete*" propagation="REQUIRED" rollback-for="java.lang.Throwable"/>
            <tx:method name="update*" propagation="REQUIRED" rollback-for="java.lang.Throwable"/>
            <tx:method name="modify*" propagation="REQUIRED" rollback-for="java.lang.Throwable"/>
            <tx:method name="query*" read-only="true"/>
            <tx:method name="select*" read-only="true"/>
            <tx:method name="find*" read-only="true"/>
            <tx:method name="get*" read-only="true"/>
        tx:attributes>
    tx:advice>
    
    
    <aop:config>
        
        <aop:pointcut id="txPointcut" expression="execution(* com.powernode.bank.service..*(..))"/>
        
        <aop:advisor advice-ref="txAdvice" pointcut-ref="txPointcut"/>
    aop:config>
beans>

第五步: 测试配置的事务通知能否对目标对象的目标方法起到事务控制的作用

@Test
public void testTransferXml(){
    ApplicationContext applicationContext = new ClassPathXmlApplicationContext("spring.xml");
    AccountService accountService = applicationContext.getBean("accountService", AccountService.class);
    try {
        accountService.transfer("act-001", "act-002", 10000);
        System.out.println("转账成功");
    } catch (Exception e) {
        e.printStackTrace();
    }
}