spring5入门（十六）：搭建事务操作环境

• 简介

事务是数据库操作最基本单元，逻辑上一组操作，要么都成功，如果有一个失败所有操作都失败

• 事务四个特性（ACID）

原子性
一致性
隔离性
持久性

• 构建maven项目，导入依赖

<dependencies>
        <!-- 基础 -->
        <dependency>
            <groupId>commons-logging</groupId>
            <artifactId>commons-logging</artifactId>
            <version>1.1.1</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <version>5.3.18</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.3.18</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>5.3.19</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-expression</artifactId>
            <version>5.3.18</version>
        </dependency>

        <!-- aop -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aop</artifactId>
            <version>5.3.4</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aspects</artifactId>
            <version>5.3.4</version>
        </dependency>
        <dependency>
            <groupId>net.sourceforge.cglib</groupId>
            <artifactId>com.springsource.net.sf.cglib</artifactId>
            <version>2.1.3</version>
        </dependency>
        <dependency>
            <groupId>org.aopalliance</groupId>
            <artifactId>com.springsource.org.aopalliance</artifactId>
            <version>1.0.0</version>
        </dependency>
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>com.springsource.org.aspectj.weaver</artifactId>
            <version>1.6.4.RELEASE</version>
        </dependency>

        <!-- jdbcTemplate -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.2.1</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.26</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.3.4</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-orm</artifactId>
            <version>5.3.4</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>5.3.4</version>
        </dependency>
    </dependencies>

• bean.xml

    <!-- 组件扫描 -->
    <context:component-scan base-package="org.example"></context:component-scan>

    <!-- 数据库连接池 -->
    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource"
          destroy-method="close">
        <property name="url" value="jdbc:mysql://127.0.0.1:3306/jdbc" />
        <property name="username" value="root" />
        <property name="password" value="123456" />
        <property name="driverClassName" value="com.mysql.cj.jdbc.Driver" />
    </bean>

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

• 创建数据库
  

• 添加数据
  

• 代码案例

# 持久层接口
public interface UserDao {

    // 增加钱
    public void addMoney();

    // 减少钱
    public void reduceMoney();

}

# 持久层实现
@Repository
public class UserDaoImpl implements UserDao {

    @Autowired
    private JdbcTemplate jdbcTemplate;

    // goudan转账100给gousheng
    @Override
    public void reduceMoney() {
        String sql = "update t_account set money=money-? where username=?";
        jdbcTemplate.update(sql,100,"goudan");
    }

    // gousheng的账户中多100块钱
    @Override
    public void addMoney() {
        String sql = "update t_account set money=money+? where username=?";
        jdbcTemplate.update(sql,100,"gousheng");
    }

}

# 业务层
@Service
public class UserService {

    //注入dao
    @Autowired
    private UserDao userDao;

    //转账的方法
    public void accountMoney() {
        userDao.reduceMoney();
        userDao.addMoney();
    }

}

# 测试类
public class Test1 {

    @Test
    public void testAccount() {
        ApplicationContext context =
                new ClassPathXmlApplicationContext("bean1.xml");
        UserService userService = context.getBean("userService", UserService.class);
        userService.accountMoney();
    }

}

• 测试结果
  

• 报错1

org.springframework.beans.factory.BeanDefinitionStoreException: IOException parsing XML document from class path resource [ApplicationContext.xml]; nested exception is java.io.FileNotFoundException: class path resource [ApplicationContext.xml] cannot be opened because it does not exist

• 解决方案：将bean.xml放到resource目录下