【精品】seata综合示例：订单-库存-扣款

有关seata的安装，请参看博客：https://blog.csdn.net/lianghecai52171314/article/details/127330916

业务需求：下单—减库存—扣钱—改订单状态

当用户下单时，会在订单服务中创建一个订单，然后通过远程调用库存服务来扣减下单商品的库存；再通过远程调用账户服务来扣减用户账户里面的余额；最后订单服务中修改订单状态。

需要涉及到三个模块：

模块名数据库名portContext-pathApplication-namefafu-accountseata_account3001fafuFafu-account-3001fafu-storageseata_storage4001fafuFafu-storage-4001fafu-orderseata_order5001fafuFafu-order-5001

可以看出：该操作需要跨域三个数据库，有两次远程调用，需要用到分布式事务技术。

数据库准备 创建seata_order数据库，然后在其中创建表tb_order：

CREATE TABLE `tb_order`  (
  `id` bigint UNSIGNED NOT NULL COMMENT '订单编号',
  `user_id` bigint UNSIGNED NULL DEFAULT NULL COMMENT '用户编号',
  `sku_id` bigint UNSIGNED NULL DEFAULT NULL COMMENT '商品编号',
  `count` int UNSIGNED NULL DEFAULT NULL COMMENT '数量',
  `money` decimal(10, 3) UNSIGNED NULL DEFAULT NULL COMMENT '金额',
  `state` int UNSIGNED NULL DEFAULT NULL COMMENT '状态',
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8mb4 COLLATE = utf8mb4_0900_ai_ci ROW_FORMAT = Dynamic;

上面表的设计只是模拟性质的，大概对应的是拼多多的业务，一个订单中只能购买1种商品，但这种商品可以购买多个。

创建seata_storage数据库，然后在其中创建表tb_storage

CREATE TABLE `tb_storage`  (
  `id` bigint UNSIGNED NOT NULL COMMENT '编号',
  `sku_id` bigint UNSIGNED NULL DEFAULT NULL COMMENT '商品编号',
  `total` int UNSIGNED NULL DEFAULT NULL COMMENT '总库存',
  `used` int UNSIGNED NULL DEFAULT NULL COMMENT '已用库存',
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8mb4 COLLATE = utf8mb4_0900_ai_ci ROW_FORMAT = Dynamic;

创建seata_account数据库，然后在其中创建表tb_account：

CREATE TABLE `tb_account`  (
  `id` bigint UNSIGNED NOT NULL COMMENT '编号',
  `total` decimal(11, 3) UNSIGNED NULL DEFAULT NULL COMMENT '总额度',
  `used` decimal(11, 3) UNSIGNED NULL DEFAULT NULL COMMENT '已用额度',
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8mb4 COLLATE = utf8mb4_0900_ai_ci ROW_FORMAT = Dynamic;

依次在三个数据库创建undo_log 表，用于保存需要回滚的数据：

CREATE TABLE `undo_log`  (
  `id` bigint NOT NULL AUTO_INCREMENT,
  `branch_id` bigint NOT NULL,
  `xid` varchar(100) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,
  `context` varchar(128) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,
  `rollback_info` longblob NOT NULL,
  `log_status` int NOT NULL,
  `log_created` datetime NOT NULL,
  `log_modified` datetime NOT NULL,
  `ext` varchar(100) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  PRIMARY KEY (`id`) USING BTREE,
  UNIQUE INDEX `ux_undo_log`(`xid` ASC, `branch_id` ASC) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;

注：每个服务对应的业务数据库都需要创建这个日志表。

项目共同部分 Nacos中

在Nacos添加给客户端加载使用的配置seata-client-demo.yml：

• Data Id：seata-client-demo.yml
• Group：SEATA_GROUP

注意：上面配置中的group和nampespace都是在Nacos中创建命名空间时创建的。 上面配置的具体内容如下：

# seata配置
seata:
  enabled: true
  application-id: seata-cilent-deme
  # Seata 事务组编号，此处需于 seata 相同
  tx-service-group: default-tx-group
  config:
    type: nacos
    nacos:
      # nacos ip地址
      server-addr: 127.0.0.1:8848
      group: SEATA_GROUP
      namespace: 99970600-6f67-43fd-a2a2-4e9795947bf4
      data-id: seata-server.properties
  registry:
    type: nacos
    nacos:
      application: seata-server
      # nacos ip地址
      server-addr: 127.0.0.1:8848
      group: SEATA_GROUP
      namespace: 99970600-6f67-43fd-a2a2-4e9795947bf4

依赖

    org.projectlombok
    lombok



    org.springframework.boot
    spring-boot-starter-web


    org.springframework.boot
    spring-boot-starter-actuator


    org.springframework.boot
    spring-boot-devtools
    runtime
    true



    org.springframework.boot
    spring-boot-starter-test
    test




    mysql
    mysql-connector-java


    com.alibaba
    druid-spring-boot-starter


    com.baomidou
    mybatis-plus-boot-starter



    org.springframework.cloud
    spring-cloud-starter-openfeign



    org.springframework.cloud
    spring-cloud-starter-loadbalancer


    com.alibaba.cloud
    spring-cloud-starter-alibaba-nacos-discovery


    com.alibaba.cloud
    spring-cloud-starter-alibaba-sentinel



    com.alibaba.csp
    sentinel-datasource-nacos



    io.seata
    seata-spring-boot-starter
    1.5.2


    com.alibaba.cloud
    spring-cloud-starter-alibaba-seata
    
        
            io.seata
            seata-spring-boot-starter
        
    

Result

@Getter
@ToString
public class Result {
    /**
     * 请求响应状态码
     */
    private int code;
    /**
     * 请求结果描述信息
     */
    private String msg;
    /**
     * 请求结果数据
     */
    private T data;
    public Result setCode(int code) {
        this.code = code;
        return this;
    }

    public Result setMsg(String msg) {
        this.msg = msg;
        return this;
    }

    public Result setData(T data) {
        this.data = data;
        return this;
    }

    public static void main(String[] args) {
        Result result = new Result().addData("a", "aaa", "b", 123, "c", new Date());
        System.out.println(result);
    }

    /**
     * 将key-value形式的成对出现的参数转换为JSON
     *
     * @param objs
     * @return
     */
    public Result addData(Object... objs) {
        if (objs.length % 2 != 0) {
            throw new RuntimeException("参数个数不对");
        }
        for (int i = 0; i