阅读本文前,建议先阅读Spring之基于注解的声明式事务
15.1、环境搭建
创建名为spring_transaction_xml的新module,过程参考13.1节
15.1.1、配置打包方式和依赖

注意:比起基于注解的声明式事务,基于xml的声明式事务还需要额外引入spring-AOP的依赖
15.1.2、创建jdbc.properties文件
 - jdbc.driver=com.mysql.jdbc.Driver
- jdbc.url=jdbc:mysql://localhost:3306/ssm?characterEncoding=utf-8
- jdbc.username=root
- jdbc.password=root
复制代码 15.1.3、创建Spring的配置文件
 - <?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:context="http://www.springframework.org/schema/context"
- xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd">
-
- <context:property-placeholder location="jdbc.properties"></context:property-placeholder>
-
- <bean id="datasource" >
-
- <context:component-scan base-package="org.rain.spring"></context:component-scan>
-
- <context:component-scan base-package="org.rain.spring"></context:component-scan><property name="driverClassName" value="${jdbc.driver}"></property>
-
- <context:component-scan base-package="org.rain.spring"></context:component-scan><property name="url" value="${jdbc.url}"></property>
-
- <context:component-scan base-package="org.rain.spring"></context:component-scan><property name="username" value="${jdbc.username}"></property>
-
- <context:component-scan base-package="org.rain.spring"></context:component-scan><property name="password" value="${jdbc.password}"></property>
- </bean>
-
- <bean id="jdbcTemplate" >
-
- <context:component-scan base-package="org.rain.spring"></context:component-scan>
-
- <context:component-scan base-package="org.rain.spring"></context:component-scan><property name="dataSource" ref="datasource"></property>
- </bean>
- </beans>
复制代码 15.1.4、创建持久层接口BookDao及其实现类
 - package org.rain.spring.dao;
- /**
- * @author liaojy
- * @date 2023/9/3 - 17:34
- */
- public interface BookDao {
- /**
- * 查询图书的价格
- * @param bookId
- * @return
- */
- Integer getPriceByBookId(Integer bookId);
- /**
- * 更新图书的库存
- * @param bookId
- */
- void updateStockOfBook(Integer bookId);
- /**
- * 更新用户的余额
- * @param userId
- * @param price
- */
- void updateBalanceOfUser(Integer userId,Integer price);
- }
复制代码 - package org.rain.spring.dao.impl;
- import org.rain.spring.dao.BookDao;
- import org.springframework.beans.factory.annotation.Autowired;
- import org.springframework.jdbc.core.JdbcTemplate;
- import org.springframework.stereotype.Repository;
- /**
- * @author liaojy
- * @date 2023/9/3 - 17:36
- */
- @Repository
- public class BookDaoImpl implements BookDao {
- @Autowired
- private JdbcTemplate jdbcTemplate;
- public Integer getPriceByBookId(Integer bookId) {
-
- <context:component-scan base-package="org.rain.spring"></context:component-scan>String sql = "select price from t_book where book_id = ?";
-
- <context:component-scan base-package="org.rain.spring"></context:component-scan>Integer price = jdbcTemplate.queryForObject(sql, Integer.class,bookId);
-
- <context:component-scan base-package="org.rain.spring"></context:component-scan>return price;
- }
- public void updateStockOfBook(Integer bookId) {
-
- <context:component-scan base-package="org.rain.spring"></context:component-scan>String sql = "update t_book set stock = stock -1 where book_id = ?";
-
- <context:component-scan base-package="org.rain.spring"></context:component-scan>jdbcTemplate.update(sql, bookId);
- }
- public void updateBalanceOfUser(Integer userId, Integer price) {
-
- <context:component-scan base-package="org.rain.spring"></context:component-scan>String sql = "update t_user set balance = balance - ? where user_id = ?";
-
- <context:component-scan base-package="org.rain.spring"></context:component-scan>jdbcTemplate.update(sql,price,userId);
- }
- }
复制代码 15.1.5、创建业务层接口BookService及其实现类
 - package org.rain.spring.service;
- /**
- * @author liaojy
- * @date 2023/9/3 - 17:52
- */
- public interface BookService {
- void buyBook(Integer bookId,Integer userId);
- }
复制代码 - package org.rain.spring.service.impl;
- import org.rain.spring.dao.BookDao;
- import org.rain.spring.service.BookService;
- import org.springframework.beans.factory.annotation.Autowired;
- import org.springframework.stereotype.Service;
- /**
- * @author liaojy
- * @date 2023/9/3 - 17:53
- */
- @Service
- public class BookServiceImpl implements BookService {
- @Autowired
- private BookDao bookDao;
- public void buyBook(Integer bookId, Integer userId) {
-
- <context:component-scan base-package="org.rain.spring"></context:component-scan>//查询图书的价格
-
- <context:component-scan base-package="org.rain.spring"></context:component-scan>Integer price = bookDao.getPriceByBookId(bookId);
-
- <context:component-scan base-package="org.rain.spring"></context:component-scan>//更新图书的库存
-
- <context:component-scan base-package="org.rain.spring"></context:component-scan>bookDao.updateStockOfBook(bookId);
-
- <context:component-scan base-package="org.rain.spring"></context:component-scan>//更新用户的余额
-
- <context:component-scan base-package="org.rain.spring"></context:component-scan>bookDao.updateBalanceOfUser(userId,price);
- }
- }
复制代码 15.1.6、创建控制层BookController

注意:因为控制层没用到接口,所以方法的访问修饰符要手动设置
- package org.rain.spring.controller;
- import org.rain.spring.service.BookService;
- import org.springframework.beans.factory.annotation.Autowired;
- import org.springframework.stereotype.Controller;
- /**
- * @author liaojy
- * @date 2023/9/3 - 17:54
- */
- @Controller
- public class BookController {
- @Autowired
- private BookService bookService;
- public void buyBook(Integer bookId, Integer userId){
-
- <context:component-scan base-package="org.rain.spring"></context:component-scan>bookService.buyBook(bookId,userId);
- }
- }
复制代码 15.1.7、配置对注解组件的扫描
 -
- <context:component-scan base-package="org.rain.spring"></context:component-scan>
复制代码 15.2、基于xml事务的实现
15.2.1、配置事务管理器
 -
- <context:component-scan base-package="org.rain.spring"></context:component-scan>
- <context:component-scan base-package="org.rain.spring"></context:component-scan>
- <context:component-scan base-package="org.rain.spring"></context:component-scan>
复制代码 15.2.2、配置事务通知

注意:tx:advice标签导入的名称空间需要 tx 结尾的那个
-
- <context:component-scan base-package="org.rain.spring"></context:component-scan>
复制代码 15.2.3、配置事务通知作用到连接点
 -
- <context:component-scan base-package="org.rain.spring"></context:component-scan>
- <context:component-scan base-package="org.rain.spring"></context:component-scan>
- <context:component-scan base-package="org.rain.spring"></context:component-scan>
复制代码 15.2.4、配置事务通知的属性

注意:不使用tx:method标签指定的方法是不会使用事务的,为了让切入点表达式的所有方法都使用到事务,可以使用*通配符:
-
- <context:component-scan base-package="org.rain.spring"></context:component-scan>
- <context:component-scan base-package="org.rain.spring"></context:component-scan>
- <context:component-scan base-package="org.rain.spring"></context:component-scan>
- <context:component-scan base-package="org.rain.spring"></context:component-scan>
- <context:component-scan base-package="org.rain.spring"></context:component-scan>
复制代码 15.3、测试事务的效果
15.3.1、创建测试类
模拟场景:
- 用户购买图书,先查询图书的价格,再更新图书的库存和用户的余额
- 假设id为1的用户(余额为50),购买id为1的图书(价格为80)
- 购买图书之后,用户的余额应为-30;但由于数据库中余额字段设置了无符号,因此无法将-30插入到余额字段;
此时执行更新用户余额的sql语句会抛出异常
 - package org.rain.spring.test;import org.junit.Test;import org.junit.runner.RunWith;import org.rain.spring.controller.BookController;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.test.context.ContextConfiguration;import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;/** * @author liaojy * @date 2023/9/4 - 0:20 */@RunWith(SpringJUnit4ClassRunner.class)@ContextConfiguration("classpath:spring-tx-xml.xml")public class TxByXml { @Autowired private BookController bookController; @Test public void testBuyBook(){
- <context:component-scan base-package="org.rain.spring"></context:component-scan>bookController.buyBook(1,1); }}
复制代码 15.3.2、执行前的数据

此时id为1的图书库存为100

此时id为1的用户余额为50
15.3.3、执行时的异常

15.3.3、执行后的数据

由于使用了Spring的声明式事务,更新(图书)库存和更新(用户)余额,要么都成功,要么都失败;
本例属于都失败,所以(图书)库存和(用户)余额都没有变化

15.4、配置事务的属性

事务属性的详细作用,请参考14.5节
-
- <context:component-scan base-package="org.rain.spring"></context:component-scan>
复制代码 免责声明:如果侵犯了您的权益,请联系站长,我们会及时删除侵权内容,谢谢合作! |