关于nacos，seata-server，seata相关表等 创建配置请看我前面的文章。

项目结构

|-- demo
  |-- entity 实体对象(为了让其他服务拥有所有服务对象)
  |-- order 订单 (pom导入了 entity )
  |-- stock 库存 (pom导入了 entity )
  |-- user 用户 (pom导入了 entity )

项目依赖

entity

    <properties>
        <mybatis-plus>3.3.1.tmp</mybatis-plus>
        <db-drive>1.1.23</db-drive>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>

        <!-- 数据持久相关配置 -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>${mybatis-plus}</version>
        </dependency>

        <!-- 驱动 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>${db-drive}</version>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>

        <!-- nacos 注册中心 -->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>

        <!-- 多数据源，seata分布式事务 -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>dynamic-datasource-spring-boot-starter</artifactId>
            <version>3.2.0</version>
        </dependency>
    </dependencies>

order、stock、user

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>com.example</groupId>
            <artifactId>entity</artifactId>
            <version>0.0.1-SNAPSHOT</version>
        </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>
            <version>2.2.1.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>io.seata</groupId>
            <artifactId>seata-spring-boot-starter</artifactId>
            <version>1.3.0</version>
        </dependency>

        <dependency>
            <groupId>io.seata</groupId>
            <artifactId>seata-all</artifactId>
            <version>1.3.0</version>
        </dependency>
    </dependencies>

配置文件

因为里面有nacos服务注册，所以会有两个配置文件，但配置文件基本一样，所以我就挑user服务的。

bootstrap.properties

注意 spring.application.name 不同服务这里是不一样的

#spring.profiles.active=dev
# Nacos Server 的地址
#spring.cloud.nacos.config.server-addr=0.0.0.0:8848
spring.cloud.nacos.config.server-addr=127.0.0.1:8848
# 这里的对应 Nacos Server 中的 Data ID 的前缀
spring.application.name=user-server
# 这里的对应 Nacos Server  中的指定的配置规则格式和 Data ID 的后缀
spring.cloud.nacos.config.file-extension=yaml
# 关闭动态刷新，默认是开启
spring.cloud.nacos.config.refresh.enabled=false

# 服务发现
#spring.cloud.nacos.discovery.server-addr=0.0.0.0:8848
spring.cloud.nacos.discovery.server-addr=127.0.0.1:8848
# 值范围：1到100。值越大，重量越大。
spring.cloud.nacos.discovery.weight=1
# 集群名称
spring.cloud.nacos.discovery.cluster-name=user
# 心跳间隔 10秒
spring.cloud.nacos.discovery.heart-beat-interval=10000
# sentinel 日志
# spring.cloud.sentinel.log.dir=./sentinel/log

application.yml

以下为多数据源配置，但相关服务只需要配置相关库就行。

server:
  port: 8082

spring:
  main:
    allow-bean-definition-overriding: true
  autoconfigure:
    exclude: com.alibaba.druid.spring.boot.autoconfigure.DruidDataSourceAutoConfigure
  datasource:
    druid:
      stat-view-servlet:
        enabled: true
        url-pattern: "/druid/*"
        allow: 127.0.0.1
        deny: 192.168.1.73
        reset-enable: true
        login-username: admin
        login-password: admin@2020
      web-stat-filter:
        enabled: true
        url-pattern: "/*"
        exclusions: "*.js,*.gif,*.jpg,*.bmp,*.png,*.css,*.ico,/druid/*"
    dynamic:
      druid:
        filters: stat,wall
        initial-size: 10
        min-idle: 10
        maxActive: 200
        maxWait: 10000
        useUnfairLock: true
        validation-query: 'select 1'
        testWhileIdle: true
        testOnBorrow: false
        testOnReturn: false
      primary: user
      # 启用严格模式
      strict: true
      seata: true
      seata-mode: AT
      datasource:
        user:
          url: jdbc:mysql://0.0.0.0:3306/user?useUnicode=true&characterEncoding=UTF-8&autoReconnect=true&useSSL=false&zeroDateTimeBehavior=convertToNull&&serverTimezone=Asia/Shanghai
          driver-class-name: com.mysql.cj.jdbc.Driver
          type: com.alibaba.druid.pool.DruidDataSource
          username: dev
          password: mysql@dev.2020
          # 建表脚本
          # schema: classpath:db/schema-account.sql
#        order:
#          url: jdbc:mysql://0.0.0.0:3306/order?useUnicode=true&characterEncoding=UTF-8&autoReconnect=true&useSSL=false&zeroDateTimeBehavior=convertToNull&&serverTimezone=Asia/Shanghai
#          driver-class-name: com.mysql.cj.jdbc.Driver
#          type: com.alibaba.druid.pool.DruidDataSource
#          username: dev
#          password: mysql@dev.2020
#        stock:
#          url: jdbc:mysql://0.0.0.0:3306/stock?useUnicode=true&characterEncoding=UTF-8&autoReconnect=true&useSSL=false&zeroDateTimeBehavior=convertToNull&&serverTimezone=Asia/Shanghai
#          driver-class-name: com.mysql.cj.jdbc.Driver
#          type: com.alibaba.druid.pool.DruidDataSource
#          username: dev
#          password: mysql@dev.2020

seata:
  enabled: true
  # 启用自动代理数据源
  enable-auto-data-source-proxy: false
  # 随便起个名字,但最好与服务名称一致
  application-id: ${spring.application.name}
  # 此处的名称一定要与 vgroup-mapping下配置的参数保持一致
  tx-service-group: my_test_tx_group
  # 目的是找 seata 的配置
  config:
    type: nacos
    nacos:
      server-addr: 127.0.0.1:8848
      username: nacos
      password: nacos@root@2020
      namespace:
      group: SEATA_GROUP
  # registry 目的是找 seata-server 服务
  registry:
    type: nacos
    nacos:
      application: seata-server
      server-addr: 127.0.0.1:8848
      username: nacos
      password: nacos@root@2020
      namespace:

代码

关于实体表的结构在上一篇文章已经有了，这里直接跳过。

entity

entity 被所有服务所引用，所以这里直接写 Feign接口是最方便的。

@FeignClient(value = "user-server",path = "/account")
public interface AccountApi {

    @PostMapping("/debit")
    void debit(@RequestParam("uid") Integer uid, @RequestParam("money") Integer money);
}

@FeignClient(value = "order-server",path = "/order")
public interface OrderApi {

    @PostMapping("/create")
    void create(@RequestParam("uid") Integer uid,
                       @RequestParam("stockId") Integer stockId,
                       @RequestParam("count") Integer count,
                       @RequestParam("money") Integer money
    );
}

@FeignClient(value = "stock-server",path = "/stock")
public interface StockApi {

    @PostMapping("/deduct")
    Integer deduct(@RequestParam("stockId") Integer stockId, @RequestParam("count") Integer count);
}

order，stock，user

关于 order，stock，user的mapper 和 server 已经在上一篇写过了，只需要把他们放到对应的服务里面即可。然后修改实现类，把里面调用其他的server改成调用 xxxApi即可，在添加一层 controller。以order为例：

@Service
public class OrderServerImpl implements OrderServer {

    @Autowired
    private OrderMapper orderMapper;
    @Autowired
    private AccountApi accountApi;

    @Override
    public void create(Integer uid, Integer stockId, Integer count,Integer money) {
        accountApi.debit(uid,money);
        Order order = new Order();
        order.setUid(uid);
        order.setTime(new Date());
        order.setCount(count);
        order.setMoney(money);
        if(1==1){
            throw new RuntimeException("下单异常");
        }
        orderMapper.insert(order);
    }
}

@RestController
@RequestMapping("/order")
public class OrderController {

    @Autowired
    private OrderServer orderServer;

    @PostMapping("/create")
    public void create(@RequestParam("uid") Integer uid,
                       @RequestParam("stockId") Integer stockId,
                       @RequestParam("count") Integer count,
                       @RequestParam("money") Integer money
    ){
        orderServer.create(uid, stockId, count, money);
    }
}

这里我们可以看到 order里面其实有抛异常的动作。
再说一遍我们的测试方案是：

采购开始 -> 减库存，得到所需花费金额 -> 用户减去所需花费金额 -> 创建订单

编写调用类

调用类我是在 user服务里面做的，方法为 purchase

@RestController
@RequestMapping("/account")
public class AccountController {

    @Autowired
    private AccountServer accountServer;
    @Autowired
    private BusinessService businessService;

    @PostMapping("/debit")
    public void debit(@RequestParam("uid") Integer uid, @RequestParam("money") Integer money){
        accountServer.debit(uid, money);
    }

    @PostMapping("/purchase")
    public void purchase(@RequestParam("uid") Integer uid,@RequestParam("stockId") Integer stockId ,@RequestParam("count") Integer count){
        businessService.purchase(uid, stockId,count);
    }

}

再贴一下 BusinessServiceImpl

@Service
public class BusinessServiceImpl implements BusinessService {

    @Autowired
    private StockApi stockApi;
    @Autowired
    private OrderApi orderApi;

    @GlobalTransactional
    @Override
    public void purchase(Integer uid, Integer stockId, Integer count) {
        Integer money = stockApi.deduct(stockId, count);
        orderApi.create(uid, stockId, count,money);
    }
}

@GlobalTransactional 全局事务(分布式事务注解)

启动所有服务

服务全部启动成功之后，你会在nacos看到如下：

测试

这里直接测试下单异常，会不会出现订单没创建，但是已经扣库存和余额。

检查数据库数据：

stock：id=1，num=500，price=5
account：id=1，amount=2000
order：

没有进行扣除，证明服务调用的分布式事务起作用的。