Seata入门系列【2】Spring Cloud 2021.0.5集成seata 1.7.1

桃扇骨 2023-10-16 15:17 36阅读 0赞

## 1 引出分布式事务问题 ##

### 1.1 seata-service-account编写查询用户、远程调用下订单接口 ###

@RestController
    @RequestMapping("/accountTbl")
    public class AccountTblController {
        
    
        @Autowired
        AccountTblMapper accountTblMapper;
        @Autowired
        OrderFeign orderFeign;
    
    
        @GetMapping("/insertOrder")
        public Object insertOrder() {
        
            // 查询用户
            AccountTbl accountTbl = accountTblMapper.selectById("11111111");
            // 下单
            Object order = orderFeign.insertOrder(accountTbl.getUserId(), "iphone11", 1, 1);
            // 修改余额
            accountTbl.setMoney(accountTbl.getMoney() - 1);
            accountTblMapper.updateById(accountTbl);
            return order;
        }
    }

@FeignClient(name = "seata-service-order")
    public interface OrderFeign {
        
    
        @GetMapping("orderTbl/insertOrder")
        Object insertOrder(@RequestParam String userId,@RequestParam  String commodityCode,@RequestParam  int count,@RequestParam  int money);
    }

### 1.2 seata-service-order编写下订单，远程调用减库存接口 ###

@RestController
    @RequestMapping("/orderTbl")
    public class OrderTblController {
        
        @Autowired
        OrderTblMapper orderTblMapper;
        @Autowired
        StorageFeign storageFeign;
    
        @GetMapping("insertOrder")
        public Object insertOrder(String userId, String commodityCode, int count, int money) {
        
            // 下定单
            OrderTbl orderTbl = new OrderTbl();
            orderTbl.setUserId(userId);
            orderTbl.setCommodityCode(commodityCode);
            orderTbl.setCount(count);
            orderTbl.setMoney(1);
            // 下订单扣库存
            orderTblMapper.insert(orderTbl);
            Object storage = storageFeign.updateStorage(commodityCode, count);
            return orderTbl;
        }
    }

@FeignClient(name = "seata-service-storage")
    public interface StorageFeign {
        
        @GetMapping("/storageTbl/updateStorage")
        Object updateStorage(@RequestParam String commodityCode,@RequestParam  int count);
    }

### 1.3 seata-service-storage编写减库存接口 ###

@RestController
    @RequestMapping("/storageTbl")
    public class StorageTblController {
        
        @Autowired
        StorageTblMapper storageTblMapper;
    
        @GetMapping("updateStorage")
        Object updateStorage(String commodityCode, int count){
        
            // 查询库存
            StorageTbl storageTbl = storageTblMapper.selectOne(new LambdaQueryWrapper<StorageTbl>().eq(StorageTbl::getCommodityCode, commodityCode));
            // 减去库存更新
            storageTbl.setCount(storageTbl.getCount()-count);
            int i = storageTblMapper.updateById(storageTbl);
            return storageTbl;
        }
    }

### 1.4 引出分布式事务 ###

当我们关闭seata-service-storage服务,访问/accountTbl/insertOrder接口,会发现下单成功了,但是未扣库存,所以需要引入分布式事务,对一些跨服务的改库操作进行全局管理

## 2 集成Seata解决分布式事务问题 ##

### 2.1 各个数据据添加undo\_log表 ###

CREATE TABLE `undo_log` (
      `id` bigint NOT NULL AUTO_INCREMENT,
      `branch_id` bigint NOT NULL,
      `xid` varchar(100) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL,
      `context` varchar(128) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL,
      `rollback_info` longblob NOT NULL,
      `log_status` int NOT NULL,
      `log_created` datetime NOT NULL,
      `log_modified` datetime NOT NULL,
      PRIMARY KEY (`id`) USING BTREE,
      UNIQUE KEY `ux_undo_log` (`xid`,`branch_id`) USING BTREE
    ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_general_ci;

### 2.2 父pom添加seata依赖 ###

<dependency>
                <groupId>io.seata</groupId>
                <artifactId>seata-spring-boot-starter</artifactId>
                <version>1.6.1</version>
                <exclusions>
                    <exclusion>
                        <groupId>com.alibaba</groupId>
                        <artifactId>druid</artifactId>
                    </exclusion>
                </exclusions>
            </dependency>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-starter-alibaba-seata</artifactId>
                <exclusions>
                    <exclusion>
                        <groupId>io.seata</groupId>
                        <artifactId>seata-spring-boot-starter</artifactId>
                    </exclusion>
                </exclusions>
            </dependency>

### 2.3 各模块添加yml配置 ###

seata:
      enabled: true
      application-id: seata-service-account # 添加为服务名
      tx-service-group: my_test_tx_group
      config:
        type: nacos
        nacos:
          namespace:
          serverAddr: 127.0.0.1:8848
          group: SEATA_GROUP
      registry:
        type: nacos
        nacos:
          application: seata-server
          server-addr: 127.0.0.1:8848
          group: SEATA_GROUP
          namespace:

### 2.4 调用链开端AccountTblController接口添加@GlobalTransactional注解 ###

![在这里插入图片描述][3f2e1a2cb69c46bc83305f98bd8c2720.png]

### 2.5 手动实现xid传递 ###

手动实现xid传递，实际cloud alibaba通过已实现了自动传递，但是新版openfeign移除了很多组件，需要自己实现，添加配置类，并重新去掉自动配置

/**
     * @author wuKeFan
     * @date 2020/11/27
     */
    @Component
    @ConditionalOnClass({
        RequestInterceptor.class, GlobalTransactional.class})
    public class SeataRequestInterceptor implements RequestInterceptor {
        
    
        @Override
        public void apply(RequestTemplate template) {
        
            String currentXid = RootContext.getXID();
            if (StrUtil.isNotBlank(currentXid) && !template.url().startsWith(Auth.CHECK_TOKEN_URI) && !template.url().startsWith(Auth.CHECK_RBAC_URI)) {
        
                template.header(RootContext.KEY_XID, currentXid);
            }
        }
    }

@Configuration
    public class WebMvcConfig implements WebMvcConfigurer {
        
        @Override
        public void addInterceptors(InterceptorRegistry registry) {
        
            registry.addInterceptor(new SeataHandlerInterceptor()).addPathPatterns("/**");
        }
    }

@SpringBootApplication(exclude = {
        SeataFeignClientAutoConfiguration.class})

### 2.6 启动各个项目，访问接口,全局事务提交成功 ###

![在这里插入图片描述][5f195c5567424a8eb699f0bcef096904.png]

### 2.7 模拟异常 ###

![在这里插入图片描述][2e1570f22aa143cb82893bf2e6f68f0e.png]  
当账户因为异常回滚后，并没有订单及库存数据不一致，全局事务回滚

[3f2e1a2cb69c46bc83305f98bd8c2720.png]: https://img-blog.csdnimg.cn/3f2e1a2cb69c46bc83305f98bd8c2720.png
[5f195c5567424a8eb699f0bcef096904.png]: https://img-blog.csdnimg.cn/5f195c5567424a8eb699f0bcef096904.png
[2e1570f22aa143cb82893bf2e6f68f0e.png]: https://img-blog.csdnimg.cn/2e1570f22aa143cb82893bf2e6f68f0e.png