2.Seata 1.5.2 集成Springcloud-alibaba

一.Seata-server搭建已完成前提下

详见 Seata-server搭建

二.Springcloud 项目集成Seata

项目整体测试业务逻辑是创建订单后（为了演示分布式事务，不做前置库存校验），再去扣减库存。库存不够的时候，创建的订单信息数据也会回退。

2.1 springboot，springcloud，springboot，seata项目版本的版本管理pom配置

    <!-- 统一依赖版本管理 -->
    <properties>
        <spring.boot.version>2.6.11</spring.boot.version>
        <spring-cloud.version>2021.0.4</spring-cloud.version>
        <spring-cloud-alibaba.version>2021.0.4.0</spring-cloud-alibaba.version>
        <seata.version>1.5.2</seata.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>
    
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>${spring.boot.version}</version>
                <type>pom</type>
                <scope>import</scope>
                <exclusions>
                    <exclusion>
                        <groupId>mysql</groupId>
                        <artifactId>mysql-connector-java</artifactId>
                    </exclusion>
                </exclusions>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>${spring-cloud-alibaba.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

2.2 Porduct项目seata核心依赖和配置及代码和undolog表初始化

基本的web，持久化，数据库，数据配置中心，注册中心依赖此处略。
核心pom.xml如下：

        <!--seata 分布式事务组件-->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-seata</artifactId>
        </dependency>

appliction.yml 核心配置如下：

# 端口
server:
  port: 8050
  servlet:
    context-path: /productApi

spring:
  application:
    name: dolphin-jinyi-product
  profiles:
    active: dev
  mvc:
    pathmatch:
      matching-strategy: ant_path_matcher
  main:
    allow-bean-definition-overriding: true
  cloud:
    nacos:
      # 注册中心
      discovery:
        server-addr: localhost:8848
        namespace: d6eccad6-681c-4133-b9ff-1abcd951297a
        group: DOLPHIN_GROUP
      # 配置中心
      config:
        server-addr: localhost:8848
        file-extension: yml
        group: DOLPHIN_GROUP
        namespace: d6eccad6-681c-4133-b9ff-1abcd951297a
        # 这里可以配置多个共享配置文件
        shared-configs:
          - data-id: mysql-common.yml
            group: DEFAULT_GROUP
            refresh: true
          - data-id: redis-common.yml
            group: DEFAULT_GROUP
            refresh: true
logging:
  level:
    io:
      seata: INFO
mybatis-plus:
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

seata:
  registry:
    # 配置seata的注册中心， 告诉seata client 怎么去访问seata server(TC)
    type: nacos
    nacos:
      server-addr: 127.0.0.1:8848  # seata server 所在的nacos服务地址
      application: seata-server    # seata server 的服务名seata-server ，如果没有修改可以不配
      username: nacos
      password: nacos
      group: DOLPHIN_GROUP             # seata server 所在的组，默认就是SEATA_GROUP，没有改也可以不配
      namespace: d6eccad6-681c-4133-b9ff-1abcd951297a
  config:
    type: nacos
    nacos:
      server-addr: 127.0.0.1:8848
      username: nacos
      password: nacos
      group: DOLPHIN_GROUP             # seata server 所在的组，默认就是SEATA_GROUP，没有改也可以不配
      namespace: d6eccad6-681c-4133-b9ff-1abcd951297a
      #指定Nacos上的DataId
      data-id: seata-server.yml
  tx-service-group: default_tx_group  #这里每个服务都是对应不同的映射名,在配置中心可以看到 事务分组，必须和服务器配置一样
  service:
    vgroup-mapping:
      default_tx_group: default
    grouplist:
      default: localhost:8091

java核心伪代码示例：

 */
@RestController
@RequestMapping("/product")
@Api(value = "商品Api", tags = {"商品Api"})
public class ProductController {

    @Resource
    private IProductService productService;

    @PostMapping("updateProductStock")
    @ApiOperation(value = "updateProductStock-更新商品库存", notes = "updateProductStock-更新商品库存")
    public R updateProductStock(@RequestParam(value = "productId") Integer productId,@RequestParam(value = "num")  Integer num) {
        productService.updateProductStock(productId,num);
        return R.ok();
    }
}

public interface IProductService extends IService<Product> {
    void updateProductStock(Integer productId, Integer num);
}

注：核心点在于根据产品id扣减库存的方法上需要分支事务 @Transactional(rollbackFor = Exception.class)注解。

@Service
public class ProductServiceImpl extends ServiceImpl<ProductMapper, Product> implements IProductService {

    @Override
    @Transactional(rollbackFor = Exception.class)
    public void updateProductStock(Integer productId, Integer num) {
        System.out.println("事务id---------------------->" + RootContext.getXID());
        LambdaQueryWrapper<Product> queryWrapper = new LambdaQueryWrapper<Product>()
                .eq(Product::getProductId, productId)
                .eq(Product::getStatus, 1).last("limit 1");
        Product product = this.getOne(queryWrapper);
        if (Objects.isNull(product)) {
           //商品不存在时抛异常
            throw new BizException(ResultCodeEnum.DATA_NOT_FOUND);
        }
        Integer stockNum = product.getStockNum() + num;
        if (stockNum < 0) {
            //库存不足时，抛异常
            throw new BizException(ResultCodeEnum.PRODUCT_STOCK_NOT_ENOUGH);
        }
        product.setStockNum(stockNum);
        this.updateById(product);
    }
}

在product项目对应的数据库中初始化undo_log表

CREATE TABLE `undo_log` (
  `branch_id` bigint(20) NOT NULL COMMENT 'branch transaction id',
  `xid` varchar(128) NOT NULL COMMENT 'global transaction id',
  `context` varchar(128) NOT NULL COMMENT 'undo_log context,such as serialization',
  `rollback_info` longblob NOT NULL COMMENT 'rollback info',
  `log_status` int(11) NOT NULL COMMENT '0:normal status,1:defense status',
  `log_created` datetime(6) NOT NULL COMMENT 'create datetime',
  `log_modified` datetime(6) NOT NULL COMMENT 'modify datetime',
  UNIQUE KEY `ux_undo_log` (`xid`,`branch_id`),
  KEY `ix_log_created` (`log_created`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci COMMENT='AT transaction mode undo table';

2.3 Order项目seata核心依赖和配置及代码和undolog表初始化

基本的web，持久化，数据库，数据配置中心，注册中心依赖此处略。
核心pom.xml如下：

        <!--seata 分布式事务组件-->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-seata</artifactId>
        </dependency>

appliction.yml 核心配置如下：

# 端口
server:
  port: 8010
  servlet:
    context-path: /orderApi

spring:
  application:
    name: dolphin-jinyi-order
  profiles:
    active: dev
  mvc:
    pathmatch:
      matching-strategy: ant_path_matcher
  main:
    allow-bean-definition-overriding: true
  cloud:
    nacos:
      # 注册中心
      discovery:
        server-addr: localhost:8848
        namespace: d6eccad6-681c-4133-b9ff-1abcd951297a
        group: DOLPHIN_GROUP
      # 配置中心
      config:
        server-addr: localhost:8848
        file-extension: yml
        group: DOLPHIN_GROUP
        namespace: d6eccad6-681c-4133-b9ff-1abcd951297a
        # 这里可以配置多个共享配置文件
        shared-configs:
          - data-id: redis-common.yml
            group: DEFAULT_GROUP
            refresh: true

mybatis-plus:
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
seata:
  registry:
    # 配置seata的注册中心， 告诉seata client 怎么去访问seata server(TC)
    type: nacos
    nacos:
      server-addr: 127.0.0.1:8848  # seata server 所在的nacos服务地址
      application: seata-server    # seata server 的服务名seata-server ，如果没有修改可以不配
      username: nacos
      password: nacos
      group: DOLPHIN_GROUP             # seata server 所在的组，默认就是SEATA_GROUP，没有改也可以不配
      namespace: d6eccad6-681c-4133-b9ff-1abcd951297a
  config:
    type: nacos
    nacos:
      server-addr: 127.0.0.1:8848
      username: nacos
      password: nacos
      group: DOLPHIN_GROUP             # seata server 所在的组，默认就是SEATA_GROUP，没有改也可以不配
      namespace: d6eccad6-681c-4133-b9ff-1abcd951297a
        #指定Nacos上的DataId
      data-id: seata-server.yml
  tx-service-group: default_tx_group  #这里每个服务都是对应不同的映射名,在配置中心可以看到
  service:
    vgroup-mapping:
      default_tx_group: default
    grouplist:
      default: localhost:8091

java核心伪代码示例：

@RestController
@RequestMapping("/order")
@Api(value = "订单Api", tags = {"订单Api"})
public class OrderController {

    @Resource
    private IOrderService orderService;

    @ApiOperation(value = "createOrder-创建订单", notes = "createOrder-创建订单")
    @PostMapping("/createOrder")
    public R<Long> createOrder(@RequestBody @Validated OrderCreateDTO orderCreateDTO) {
        Long orderNo = orderService.createOrder(orderCreateDTO);
        return R.ok(orderNo);
    }
}

public interface IOrderService extends IService<Order> {
    Long createOrder(OrderCreateDTO orderCreateDTO);
}

注：核心注解 @GlobalTransactional

@Service
public class OrderServiceImpl extends ServiceImpl<OrderMapper, Order> implements IOrderService {

    @Resource
    private ProductServiceFeignClient productServiceFeignClient;


    public Long createOrderNo() {
        return IdUtil.getSnowflakeNextId();
    }

    @Override
    @GlobalTransactional
    public Long createOrder(OrderCreateDTO orderCreateDTO) {
        System.out.println("事务id---------------------->" + RootContext.getXID());
        Order order = new Order();
        BeanUtil.copyProperties(orderCreateDTO, order);
        order.setOrderNo(this.createOrderNo());
        //创建订单
        this.insertOrder(order);
        //通过feign调用商品服务扣减库存
        productServiceFeignClient.updateProductStock(order.getProductId(), -1);
        return order.getOrderNo();
    }

    @Transactional(rollbackFor = Exception.class)
    public void insertOrder(Order order) {
        System.out.println("事务id A---------------------->" + RootContext.getXID());
        boolean save = this.save(order);
        if (!save) {
            throw new BizException(ResultCodeEnum.SYSTEM_EXECUTION_ERROR);
        }
    }

}

在order项目对应的数据库中初始化undo_log表

CREATE TABLE `undo_log` (
  `branch_id` bigint(20) NOT NULL COMMENT 'branch transaction id',
  `xid` varchar(128) NOT NULL COMMENT 'global transaction id',
  `context` varchar(128) NOT NULL COMMENT 'undo_log context,such as serialization',
  `rollback_info` longblob NOT NULL COMMENT 'rollback info',
  `log_status` int(11) NOT NULL COMMENT '0:normal status,1:defense status',
  `log_created` datetime(6) NOT NULL COMMENT 'create datetime',
  `log_modified` datetime(6) NOT NULL COMMENT 'modify datetime',
  UNIQUE KEY `ux_undo_log` (`xid`,`branch_id`),
  KEY `ix_log_created` (`log_created`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci COMMENT='AT transaction mode undo table';

三.设计到的nacos中的seata-server.yml等配置

注意上面项目的yml配置中的namespace，groupId，data-id 保持和nacos一直

seata-server.yml

service:
  vgroupMapping:
    default_tx_group: default

四 测试

测试时，保证seata-server order product 服务都已经启动。
现在库存有一个，没有订单信息数据。

4.1 第一次下单

商品表库存被扣减，创建订单成功


现在库存为0.第二次下单

订单没有新增，库存也没有扣减。分布式事务测试ok