springCloud alibaba：Seata--分布式事务-蒲公英云

文章目录

1.搭建服务
2.建表
- 2.1 order服务下的表
- 2.2 stock服务下的表
3.实现服务
- 3.1 新建下单服务（OrderServer模块）
- 3.2 添加商品信息获取以及库存消减服务（stockServer模块）
4.启动Seata
- 4.1 安装 Seata
5.使用Seata实现事务控制
- 5.1 初始化数据表
- 5.2 添加配置
- - 5.2.1 添加依赖
  - 5.2.2 DataSourceProxyConfig
  - 5.2.3 registry.conf
  - 5.2.4 修改application.properties文件
- 5.3 在服务上开启全局事务
6.测试

理论知识，在《分布式事务解决方案》已经讲解的十分通透了，本文主要讲解如何通过Seata实现分布式事务控制
我们以订单微服务模块进行演示，然后由订单微服务调用商品微服务扣除库存
实现流程如下：
在这里插入图片描述

1.搭建服务

我们创建两个微服务模块，服务模块：

orderServer
stockServer

同时将两个服务集成fegin，mybatis，rabbitMq并且保证可以注册到nacos，具体如何创建和集成大家可以参考：

《SpringCloud alibaba实战》

2.建表

2.1 order服务下的表

tb_order(订单表)

DROP TABLE IF EXISTS tb_order;
CREATE TABLE tb_order (
order_id int NOT NULL AUTO_INCREMENT,
user_id int DEFAULT NULL,
product_id int DEFAULT NULL COMMENT ‘产品ID’,
order_time datetime DEFAULT NULL COMMENT ‘下单时间 ‘,
transfer_money double DEFAULT NULL COMMENT ‘交易金额’,
product_num int DEFAULT NULL COMMENT ‘购买商品数量’,
PRIMARY KEY (order_id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

2.2 stock服务下的表

tb_product(产品信息表)

DROP TABLE IF EXISTS tb_product;
CREATE TABLE tb_product (
product_id int NOT NULL AUTO_INCREMENT,
product_name varchar(255) DEFAULT NULL COMMENT ‘产品名称’,
price double(10,2) DEFAULT NULL COMMENT ‘价格’,
rest_num int DEFAULT NULL COMMENT ‘产品剩余数量’,
PRIMARY KEY (product_id)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;

— Records of tb_product

INSERT INTO tb_product VALUES (‘1’, ‘Nike Air’, ‘500.00’, ‘15’);

3.实现服务

3.1 新建下单服务（OrderServer模块）

@RestController
@Slf4j
public class TbOrderController {
    @Autowired
    ITbOrderService tbOrderService;
    @PostMapping("/order/prod/createOrder")
    public TbOrder createOrder(@RequestBody TbOrder tbOrder) {
        log.info("接收到{}号商品的下单请求", tbOrder.getProductId());
        return tbOrderService.createOrder(tbOrder.getProductId(), tbOrder.getProductNum());
    }
}
@Service
@Slf4j
public class TbOrderServiceImpl extends ServiceImpl<TbOrderMapper, TbOrder> implements ITbOrderService {
    @Autowired
    ProductService productService;
    @Autowired
    Sender_Direct sender_direct;
    @Override
    public TbOrder createOrder(Integer productId, Integer productNum) {
        //1.调用商品微服务获取商品信息
        Map<String, Object> productInfo = productService.getProductById(productId);
        log.info("查询到{}号商品，商品名称为：{},剩余数量：{}", productId, productInfo.get("productName"), productInfo.get("restNum"));
        //2.下单
        TbOrder tbOrder = new TbOrder();
        tbOrder.setUserId(1);
        tbOrder.setProductId(productId);
        tbOrder.setOrderTime(new Date());
        tbOrder.setTransferMoney(Double.valueOf(productInfo.get("transferMoney").toString()));
        baseMapper.insert(tbOrder);
        log.info("创建订单成功 ，订单信息为：{}", JSON.toJSONString(tbOrder));
        //3.调用商品微服务--扣减库存
        productService.reduceInventory(productId, productNum);
        //4.消息队列中投递一个下单成功的消息
        //此处调用消息队列服务
        return null;
    }

对应的fegin如下：

@FeignClient(value = "seata-stock")
public interface ProductService {
    /**
     * 通过商品id获取商品信息
     *
     * @param productId
     * @return
     */
    @RequestMapping(value = "getProductById", method = RequestMethod.POST)
    public Map<String, Object> getProductById(@RequestParam(value = "productId") Integer productId);
    /**
     * 通过商品id扣减库存
     *
     * @param productId
     * @return
     */
    @RequestMapping(value = "reduceInventory", method = RequestMethod.POST)
    public Integer reduceInventory(@RequestParam(value = "productId") Integer productId,
                                   @RequestParam(value = "num") Integer num);
}

3.2 添加商品信息获取以及库存消减服务（stockServer模块）

@RestController
public class TbProductController {
    @Autowired
    ITbProductService productService;
    /**
     * 通过商品id获取商品信息
     *
     * @param productId
     * @return
     */
    @RequestMapping(value = "getProductById", method = RequestMethod.POST)
    public TbProduct getProductById(@RequestParam(value = "productId") Integer productId) {
        return productService.getById(productId);
    }
    /**
     * 通过商品id扣减库存
     *
     * @param productId
     * @return
     */
    @RequestMapping(value = "reduceInventory", method = RequestMethod.POST)
    public Integer reduceInventory(@RequestParam(value = "productId") Integer productId,
                                   @RequestParam(value = "num") Integer num) {
        return productService.reduceInventory(productId, num);
    }
}
/**
 * <p>
 * 服务实现类
 * </p>
 *
 * @author astupidcoder
 * @since 2022-04-21
 */
@Service
public class TbProductServiceImpl extends ServiceImpl<TbProductMapper, TbProduct> implements ITbProductService {
    @Override
    public Integer reduceInventory(Integer productId, Integer num) {
        TbProduct tbProduct = baseMapper.selectById(productId);
        if (tbProduct.getRestNum() < num) {
            throw new RuntimeException("库存不足");
        }
        int i = 1 / 0;//此处用于模拟异常
        tbProduct.setRestNum(tbProduct.getRestNum() - num);
        return baseMapper.update(tbProduct, null);
    }
}

4.启动Seata

4.1 安装 Seata

《docker部署Seata》
《windows安装seata》

5.使用Seata实现事务控制

5.1 初始化数据表

在我们的数据库中加入一张undo_log表,这是Seata记录事务日志要用到的表

DROP TABLE IF EXISTS `undo_log`;
CREATE TABLE `undo_log` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `branch_id` bigint(20) NOT NULL,
  `xid` varchar(100) COLLATE utf8_bin NOT NULL,
  `context` varchar(255) COLLATE utf8_bin NOT NULL,
  `rollback_info` longblob NOT NULL,
  `log_status` int(11) NOT NULL,
  `log_created` datetime NOT NULL ON UPDATE CURRENT_TIMESTAMP,
  `log_modified` datetime NOT NULL ON UPDATE CURRENT_TIMESTAMP,
  `ext` varchar(100) COLLATE utf8_bin DEFAULT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `ux_undo_log` (`branch_id`,`xid`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin;

5.2 添加配置

在需要进行分布式控制的微服务中进行下面几项配置:

5.2.1 添加依赖

<!-- https://mvnrepository.com/artifact/com.alibaba.cloud/spring-cloud-starter-alibaba-seata -->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-seata</artifactId>
            <version>2021.1</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/com.alibaba.cloud/spring-cloud-starter-alibaba-nacos-config -->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
            <version>2021.1</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-bootstrap</artifactId>
        </dependency>

5.2.2 DataSourceProxyConfig

Seata 是通过代理数据源实现事务分支的，所以需要配置 io.seata.rm.datasource.DataSourceProxy 的Bean，且是 @Primary默认的数据源，否则事务不会回滚，无法实现分布式事务

import com.alibaba.druid.pool.DruidDataSource;
import io.seata.rm.datasource.DataSourceProxy;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
@Configuration
public class DataSourceProxyConfig {
    @Bean
    @ConfigurationProperties(prefix = "spring.datasource")
    public DruidDataSource druidDataSource() {
        return new DruidDataSource();
    }
    @Primary
    @Bean
    public DataSourceProxy dataSource(DruidDataSource druidDataSource) {
        return new DataSourceProxy(druidDataSource);
    }
}

5.2.3 registry.conf

在resources下添加Seata的配置文件 registry.conf

registry {
 type = "nacos"
 nacos {
   serverAddr = "localhost"
   namespace = "public"
   cluster = "default"
 }
}
config {
 type = "nacos"
 nacos {
   serverAddr = "localhost"
   namespace = "public"
   cluster = "default"
  }
}

注意：serverAddr按照你自己的naocs地址进行修改

5.2.4 修改application.properties文件

nacos.ip=192.168.28.133
#------------------------------------------------------------------------------------------------------------------------
server.port=8082
spring.application.name=seata-order
spring.cloud.nacos.discovery.server-addr=${
    nacos.ip}:8848
spring.cloud.nacos.discovery.namespace=public
spring.cloud.nacos.discovery.group=SEATA_GROUP
spring.cloud.nacos.discovery.username=nacos
spring.cloud.nacos.discovery.password=nacos
spring.main.allow-circular-references=true
#-----------------------------------------------------------------------------------------------------------------------
# 开启自动装配
seata.enabled=true
# 是否开启数据源自动代理，一定要为 false,否则会和mp冲突
seata.enable-auto-data-source-proxy=false
# 事务分组，程序会通过用户的配置中心去寻找service.vgroupMapping
seata.tx-service-group=my_test_tx_group
seata.config.type=nacos
seata.config.nacos.server-addr=${
    nacos.ip}:8848
seata.config.nacos.namespace=public
seata.config.nacos.group=SEATA_GROUP
seata.config.nacos.username=nacos
seata.config.nacos.password=nacos
seata.registry.type=nacos
seata.registry.nacos.server-addr=${
    nacos.ip}:8848
seata.registry.nacos.namespace=public
seata.registry.nacos.username=nacos
seata.registry.nacos.password=nacos
seata.registry.nacos.application=seata-server
seata.registry.nacos.group=SEATA_GROUP
# 事务群组，my_test_tx_group为分组，配置项值为TC集群名
seata.service.vgroup-mapping.my_test_tx_group=default
seata.service.disable-global-transaction=false
seata.client.rm.report-success-enable=false