Spring声明式事务

<dependencies>
<!-- 基于Maven依赖传递性，导入spring-context依赖即可导入当前所需所有jar包 -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>5.3.1</version>
</dependency>
<!-- Spring 持久化层支持jar包 -->
<!-- Spring 在执行持久化层操作、与持久化层技术进行整合过程中，需要使用orm、jdbc、tx三个
jar包 -->
<!-- 导入 orm 包就可以通过 Maven 的依赖传递性把其他两个也导入 -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-orm</artifactId>
<version>5.3.1</version>
</dependency>
<!-- Spring 测试相关 -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>5.3.1</version>
</dependency>
<!-- junit测试 -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
<!-- MySQL驱动 -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.16</version>
</dependency>
<!-- 数据源 -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.0.31</version>
</dependency>
</dependencies>

<!--导入外部属性文件-->
<context:property-placeholderlocation="classpath:jdbc.properties"/>
<!--配置数据源-->
<beanid="druidDataSource"class="com.alibaba.druid.pool.DruidDataSource"> 
 <propertyname="url"value="${atguigu.url}"/>
  <propertyname="driverClassName"value="${atguigu.driver}"/>
  <propertyname="username"value="${atguigu.username}"/>
  <propertyname="password"value="${atguigu.password}"/>
</bean>
<!--配置JdbcTemplate-->
<beanid="jdbcTemplate"class="org.springframework.jdbc.core.JdbcTemplate">  <!--装配数据源-->
  <propertyname="dataSource"ref="druidDataSource"/>
</bean>

<!--扫描组件-->
<context:component-scanbase-package="com.atguigu.spring.tx.annotation">
</context:component-scan>
<!--导入外部属性文件-->
<context:property-placeholderlocation="classpath:jdbc.properties"/>
<!--配置数据源-->
<beanid="druidDataSource"class="com.alibaba.druid.pool.DruidDataSource">  
<propertyname="url"value="${jdbc.url}"/>
  <propertyname="driverClassName"value="${jdbc.driver}"/>
  <propertyname="username"value="${jdbc.username}"/>
  <propertyname="password"value="${jdbc.password}"/>
</bean>
<!--配置JdbcTemplate-->
<beanid="jdbcTemplate"class="org.springframework.jdbc.core.JdbcTemplate">
  <!--装配数据源-->
  <propertyname="dataSource"ref="druidDataSource"/>
</bean>

REATETABLE`t_book`(
book_id`int(11)NOTNULLAUTO_INCREMENTCOMMENT'主键',
`book_name`varchar(20)DEFAULTNULLCOMMENT'图书名称',
`price`int(11)DEFAULTNULLCOMMENT'价格',
`stock`int(10)unsignedDEFAULTNULLCOMMENT'库存（无符号）',
PRIMARYKEY(`book_id`)
)ENGINE=InnoDBAUTO_INCREMENT=3DEFAULTCHARSET=utf8;
insert into`t_book`(`book_id`,`book_name`,`price`,`stock`)values(1,'斗破苍穹',80,100),(2,'斗罗大陆',50,100);
CREATETABLE`t_user`(
`user_id`int(11)NOTNULLAUTO_INCREMENTCOMMENT'主键',
`username`varchar(20)DEFAULTNULLCOMMENT'用户名',
`balance`int(10)unsignedDEFAULTNULLCOMMENT'余额（无符号）',
PRIMARYKEY(`user_id`)
)ENGINE=InnoDBAUTO_INCREMENT=2DEFAULTCHARSET=utf8;
insert into`t_user`(`user_id`,`username`,`balance`)values(1,'admin',50);

@Controller
public class BookController {
    @Autowired
    private BookService bookService;
    public void buyBook(Integer bookId, Integer userId){
    bookService.buyBook(bookId, userId);
    }
}

public interface BookService {    
void buyBook(Integer bookId, Integer userId);
}

<bean id="transactionManager"
class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource"></property>
</bean>
<!--
开启事务的注解驱动
通过注解@Transactional所标识的方法或标识的类中所有的方法，都会被事务管理器管理事务
-->
<!-- transaction-manager属性的默认值是transactionManager，如果事务管理器bean的id正好就
是这个默认值，则可以省略这个属性 -->
<tx:annotation-driven transaction-manager="transactionManager" />

@Transactional(isolation = Isolation.DEFAULT)//使用数据库默认的隔离级别
@Transactional(isolation = Isolation.READ_UNCOMMITTED)//读未提交
@Transactional(isolation = Isolation.READ_COMMITTED)//读已提交
@Transactional(isolation = Isolation.REPEATABLE_READ)//可重复读
@Transactional(isolation = Isolation.SERIALIZABLE)//串行化