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SpringCloud Alibaba 九（Seata介紹二）

Seata 案例

我們會在項目中建立三個服務，倉儲服務，訂單服務，帳戶服務。當使用者下單時，會在訂單服務中建立一個訂單，然後通過遠端調用倉儲服務來扣減下單商品的庫存，再通過遠端調用賬戶服務來扣減使用者賬戶裡面的餘額。該操作跨越三個資料庫，有兩次遠端調用，很明顯會有分布式事務問題。

架構圖
SpringCloud Alibaba 九（Seata介紹二）

1、我們需要新增三個資料庫 seata_order、seata_account、seata_store 。

SpringCloud Alibaba 九（Seata介紹二）

2、在三個庫中建立表：

在seata_order庫中建立order 表：：

DROP TABLE IF EXISTS `order`;
CREATE TABLE `order` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `user_id` varchar(255) DEFAULT NULL,
  `commodity_code` varchar(255) DEFAULT NULL,
  `count` int(11) DEFAULT 0,
  `money` int(11) DEFAULT 0,
  `status` INT(1) DEFAULT NULL COMMENT '訂單狀态：0：建立中；1：已完結' ,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

在seata_account庫中建立account表：

DROP TABLE IF EXISTS `account`;
CREATE TABLE `account` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `user_id` varchar(255) DEFAULT NULL,
  `money` int(11) DEFAULT 0,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

INSERT INTO `seata_account`.`account`(`id`, `user_id`, `money`) VALUES (1, '1', 1000);

在seata_store庫中新增 storage表

DROP TABLE IF EXISTS `storage`;
CREATE TABLE `storage` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `commodity_code` varchar(255) DEFAULT NULL,
  `count` int(11) DEFAULT 0,
  PRIMARY KEY (`id`),
  UNIQUE KEY (`commodity_code`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

INSERT INTO `seata_store`.`storage`(`id`, `commodity_code`, `count`) VALUES (1, '1', 100);

因為SEATA AT 模式需要 UNDO_LOG 表，這個需要在每一個業務庫中建立表：

DROP TABLE IF EXISTS `undo_log`;
-- for AT mode you must to init this sql for you business database. the seata server not need it.
CREATE TABLE IF NOT EXISTS `undo_log`
(
    `branch_id`     BIGINT       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`)
) ENGINE = InnoDB
  AUTO_INCREMENT = 1
  DEFAULT CHARSET = utf8mb4 COMMENT ='AT transaction mode undo table';
SpringCloud Alibaba 九（Seata介紹二）

建立Module pcloud-alibaba-seata-order-service9001

SpringCloud Alibaba 九（Seata介紹二）
SpringCloud Alibaba 九（Seata介紹二）

修改pom檔案：

<?xml version="1.0" encoding="UTF-8"?>

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>pcloud-alibaba</artifactId>
        <groupId>com.younger.pcloud.alibaba</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>pcloud-alibaba-seata-order-service9001</artifactId>

    <name>pcloud-alibaba-seata-order-service9001</name>

    <dependencies>
        <!--nacos-->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <!--seata-->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-seata</artifactId>
            <!--排除項目自帶的包-->
            <exclusions>
                <exclusion>
                    <artifactId>seata-all</artifactId>
                    <groupId>io.seata</groupId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>io.seata</groupId>
            <artifactId>seata-all</artifactId>
            <version>1.4.2</version>
        </dependency>
        <!--feign-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <!--mysql-druid-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.37</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.1.10</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.0.0</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
    </dependencies>

</project>

新增 application.yml檔案：

server:
  port: 9001

spring:
  application:
    name: seata-order-service
  cloud:
    alibaba:
      seata:
        #自定義事務組名稱需要與seata-server中的對應
        tx-service-group: my_test_tx_group
    nacos:
      discovery:
        server-addr: localhost:8848
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/seata_order
    username: root
    password: mysql

feign:
  hystrix:
    enabled: false

logging:
  level:
    io:
      seata: info

mybatis:
  mapperLocations: classpath:mapper/*.xml
SpringCloud Alibaba 九（Seata介紹二）

目錄結構：

SpringCloud Alibaba 九（Seata介紹二）

新增registry.conf檔案：

registry.conf：

registry {
  # file 、nacos 、eureka、redis、zk、consul、etcd3、sofa、custom
  type = "nacos"

  nacos {
    application = "seata-server"
    serverAddr = "127.0.0.1:8848"
    group = "SEATA_GROUP"
    namespace = ""
    username = ""
    password = ""
  }
  eureka {
    serviceUrl = "http://localhost:8761/eureka"
    weight = "1"
  }
  redis {
    serverAddr = "localhost:6379"
    db = "0"
    password = ""
    timeout = "0"
  }
  zk {
    serverAddr = "127.0.0.1:2181"
    sessionTimeout = 6000
    connectTimeout = 2000
    username = ""
    password = ""
  }
  consul {
    serverAddr = "127.0.0.1:8500"
    aclToken = ""
  }
  etcd3 {
    serverAddr = "http://localhost:2379"
  }
  sofa {
    serverAddr = "127.0.0.1:9603"
    region = "DEFAULT_ZONE"
    datacenter = "DefaultDataCenter"
    group = "SEATA_GROUP"
    addressWaitTime = "3000"
  }
  file {
    name = "file.conf"
  }
  custom {
    name = ""
  }
}

config {
  # file、nacos 、apollo、zk、consul、etcd3、springCloudConfig、custom
  type = "nacos"

  nacos {
    serverAddr = "127.0.0.1:8848"
    namespace = ""
    group = "SEATA_GROUP"
    username = ""
    password = ""
    dataId = "seata.properties"
  }
  consul {
    serverAddr = "127.0.0.1:8500"
    aclToken = ""
  }
  apollo {
    appId = "seata-server"
    apolloMeta = "http://192.168.1.204:8801"
    namespace = "application"
    apolloAccesskeySecret = ""
  }
  zk {
    serverAddr = "127.0.0.1:2181"
    sessionTimeout = 6000
    connectTimeout = 2000
    username = ""
    password = ""
    nodePath = "/seata/seata.properties"
  }
  etcd3 {
    serverAddr = "http://localhost:2379"
  }
  file {
    name = "file.conf"
  }
  custom {
    name = ""
  }
}

這個registry.conf配置檔案可以拷貝，我們上一節配置的registry.conf檔案。

新增啟動類： SeataOrderMain9001

package com.younger.pcloud.alibaba;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.openfeign.EnableFeignClients;


@EnableFeignClients
@SpringBootApplication(exclude = DataSourceAutoConfiguration.class)
@EnableDiscoveryClient
@EnableAutoDataSourceProxy
public class SeataOrderMain9001 {

    public static void main(String[] args) {
        SpringApplication.run(SeataOrderMain9001.class, args);
    }
}

新增domain包：

新增order類：

package com.younger.pcloud.alibaba.domain;

public class Order {

    private Long id;

    private String userId;

    private String commodityCode;

    private Integer count;

    private Integer money;

    /**
     * 訂單狀态：0：建立中；1：已完結
     */
    private Integer status;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getUserId() {
        return userId;
    }

    public void setUserId(String userId) {
        this.userId = userId;
    }

    public String getCommodityCode() {
        return commodityCode;
    }

    public void setCommodityCode(String commodityCode) {
        this.commodityCode = commodityCode;
    }

    public Integer getCount() {
        return count;
    }

    public void setCount(Integer count) {
        this.count = count;
    }

    public Integer getMoney() {
        return money;
    }

    public void setMoney(Integer money) {
        this.money = money;
    }

    public Integer getStatus() {
        return status;
    }

    public void setStatus(Integer status) {
        this.status = status;
    }
}

新增 Result類：

package com.younger.pcloud.alibaba.domain;

public class Result<T> {

    private Integer code;
    private String  message;
    private T       data;
	
	public Result() {
       
    }

    public Result(Integer code, String message, T data) {
        this.code = code;
        this.message = message;
        this.data = data;
    }

    public Result(Integer code, String message) {
        this(code,message,null);
    }
	public Integer getCode() {
        return code;
    }

    public void setCode(Integer code) {
        this.code = code;
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    public T getData() {
        return data;
    }

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

}

新增config 包：

新增 MyBatisConfig類：

package com.younger.pcloud.alibaba.config;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;

@Configuration
@ComponentScan({"com.younger.pcloud.alibaba.dao"})
public class MyBatisConfig {


}

新增dao 包：

新增 OrderDao 類：

package com.younger.pcloud.alibaba.dao;

import com.younger.pcloud.alibaba.domain.Order;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;

@Mapper
public interface OrderDao {

    /**
     * 建立訂單
     * @param order
     */
    void createOrder(Order order);


    /**
     * 修改訂單狀态
     */
    void update(@Param("userId") String userId, @Param("status") Integer status);
}

新增 mapper 包：

新增 OrderMapper.xml檔案：

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<mapper namespace="com.younger.pcloud.alibaba.dao.OrderDao">
    <insert id="createOrder">
        INSERT INTO `order` (`id`, `user_id`, `commodity_code`, `count`, `money`,`status`)
        VALUES (NULL, #{userId}, #{commodityCode}, #{count}, #{money},0);
    </insert>

    <update id="update">
        UPDATE `order`
        SET status = 1
        WHERE user_id = #{userId} AND status = #{status};
    </update>
</mapper>

新增service包：

新增 OrderService類：

package com.younger.pcloud.alibaba.service;

import com.younger.pcloud.alibaba.domain.Order;

public interface OrderService {

    /**
     * 建立訂單
     */
    void createOrder(Order order);

}

新增fegin遠端調用包：

新增 AccountService類：

package com.younger.pcloud.alibaba.service.fegin;

import com.younger.pcloud.alibaba.domain.Result;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;

@FeignClient(value = "seata-account-service")
public interface AccountService {

    /**
     * 扣減賬戶餘額
     * @param userId
     * @param money
     * @return
     */
    @PostMapping("/account/decrease")
    Result decrease(@RequestParam("userId") String userId, @RequestParam("money") Integer money);
}

新增StorageService類：

package com.younger.pcloud.alibaba.service.fegin;

import com.younger.pcloud.alibaba.domain.Result;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;

@FeignClient(value = "seata-store-service")
public interface StorageService {

    /**
     * 扣減庫存
     */
    @PostMapping(value = "/storage/decrease")
    Result decrease(@RequestParam("commodityCode") String commodityCode, @RequestParam("count") Integer count);

}

新增OrderService 實作類OrderServiceImpl ：

package com.younger.pcloud.alibaba.service.impl;

import com.younger.pcloud.alibaba.dao.OrderDao;
import com.younger.pcloud.alibaba.domain.Order;
import com.younger.pcloud.alibaba.service.OrderService;
import com.younger.pcloud.alibaba.service.fegin.AccountService;
import com.younger.pcloud.alibaba.service.fegin.StorageService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;

@Service
@Slf4j
public class OrderServiceImpl implements OrderService {

    @Resource
    private OrderDao orderDao;

    @Resource
    private StorageService storageService;

    @Resource
    private AccountService accountService;

    @Override
    public void createOrder(Order order) {

        log.info("開始建立訂單....");
        //本應用建立訂單
        orderDao.createOrder(order);

        //遠端調用庫存服務扣減庫存
        log.info("order-service------扣減庫存開始");
        storageService.decrease(order.getCommodityCode(),order.getCount());
        log.info("order-service------扣減庫存結束");

        //遠端調用賬戶服務扣減餘額
        log.info("order-service-------中扣減使用者餘額開始");
        accountService.decrease(order.getUserId(),order.getMoney());
        log.info("order-service-------中扣減餘額結束");

        //修改訂單狀态為已完成
        log.info("order-service-------中修改訂單狀态開始");
        orderDao.update(order.getUserId(),0);
        log.info("order-service-------中修改訂單狀态結束");

        log.info("訂單完成！！！！！");
    }
}

新增Controller 包：

新增 OrderController 類：

package com.younger.pcloud.alibaba.controller;

import com.younger.pcloud.alibaba.domain.Order;
import com.younger.pcloud.alibaba.domain.Result;
import com.younger.pcloud.alibaba.service.OrderService;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.annotation.Resource;

@RestController
public class OrderController {

    @Resource
    private OrderService orderService;

    @PostMapping("/order/create")
    public Result createOrder(@RequestBody Order order) {
        orderService.createOrder(order);
        return new Result(200,"訂單建立成功");
    }
}
建立modul pcloud-alibaba-seata-store-service9002

目錄結構：

SpringCloud Alibaba 九（Seata介紹二）

修改pom檔案：

<?xml version="1.0" encoding="UTF-8"?>

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <parent>
    <artifactId>pcloud-alibaba</artifactId>
    <groupId>com.younger.pcloud.alibaba</groupId>
    <version>1.0-SNAPSHOT</version>
  </parent>
  <modelVersion>4.0.0</modelVersion>

  <artifactId>pcloud-alibaba-seata-store-service9002</artifactId>

  <dependencies>
    <!--nacos-->
    <dependency>
      <groupId>com.alibaba.cloud</groupId>
      <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
    </dependency>
    <!--seata-->
    <dependency>
      <groupId>com.alibaba.cloud</groupId>
      <artifactId>spring-cloud-starter-alibaba-seata</artifactId>
      <exclusions>
        <exclusion>
          <artifactId>seata-all</artifactId>
          <groupId>io.seata</groupId>
        </exclusion>
      </exclusions>
    </dependency>
    <dependency>
      <groupId>io.seata</groupId>
      <artifactId>seata-all</artifactId>
      <version>1.4.2</version>
    </dependency>
    <!--feign-->
    <dependency>
      <groupId>org.springframework.cloud</groupId>
      <artifactId>spring-cloud-starter-openfeign</artifactId>
    </dependency>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-test</artifactId>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.mybatis.spring.boot</groupId>
      <artifactId>mybatis-spring-boot-starter</artifactId>
      <version>2.0.0</version>
    </dependency>
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>5.1.37</version>
    </dependency>
    <dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>druid-spring-boot-starter</artifactId>
      <version>1.1.10</version>
    </dependency>
    <dependency>
      <groupId>org.projectlombok</groupId>
      <artifactId>lombok</artifactId>
      <optional>true</optional>
    </dependency>
  </dependencies>

</project>

新增application.yml檔案：

server:
  port: 9002

spring:
  application:
    name: seata-store-service
  cloud:
    alibaba:
      seata:
        #自定義事務組名稱需要與seata-server中的對應
        tx-service-group: my_test_tx_group
    nacos:
      discovery:
        server-addr: localhost:8848
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/seata_store
    username: root
    password: mysql

feign:
  hystrix:
    enabled: false

logging:
  level:
    io:
      seata: info

mybatis:
  mapperLocations: classpath:mapper/*.xml

拷貝 file.conf 和 registry.conf 檔案到Resource目錄下：

新增啟動類 SeataStorageServiceMain9002：

package com.younger.pcloud.alibaba;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.openfeign.EnableFeignClients;

@EnableDiscoveryClient
@EnableFeignClients
@SpringBootApplication(exclude = DataSourceAutoConfiguration.class)
@EnableAutoDataSourceProxy
public class SeataStorageServiceMain9002 {

    public static void main(String[] args) {

        SpringApplication.run(SeataStorageServiceMain9002.class ,args);
    }
}

從9001 拷貝 config 目錄和registry.conf 到 9002

新增domain 目錄：

新增Result 類:

package com.younger.pcloud.alibaba.domain;

public class Result<T> {

    private Integer code;
    private String  message;
    private T       data;

	 public Result() {
       
     }

    public Result(Integer code, String message, T data) {
        this.code = code;
        this.message = message;
        this.data = data;
    }

    public Result(Integer code, String message) {
        this(code,message,null);
    }

    public Integer getCode() {
        return code;
    }

    public void setCode(Integer code) {
        this.code = code;
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    public T getData() {
        return data;
    }

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

新增 Store 類：

package com.younger.pcloud.alibaba.domain;

public class Store {

    private Long id;

    private String commodityCode;

    private Integer count;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getCommodityCode() {
        return commodityCode;
    }

    public void setCommodityCode(String commodityCode) {
        this.commodityCode = commodityCode;
    }

    public Integer getCount() {
        return count;
    }

    public void setCount(Integer count) {
        this.count = count;
    }
}

新增dao包：

新增 StoreDao 類：

package com.younger.pcloud.alibaba.dao;

import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;

@Mapper
public interface StoreDao {


    /**
     * 扣減庫存
     */
    void decrease(@Param("commodityCode") String commodityCode, @Param("count") Integer count);

}

新增 StoreMapper.xml 檔案：

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >

<mapper namespace="com.younger.pcloud.alibaba.dao.StoreDao">

    <update id="decrease">
        UPDATE storage
        SET count    = count - #{count}
        WHERE commodity_code = #{commodityCode}
    </update>
</mapper>

新增 service 包：

新增 StoreService類：

package com.younger.pcloud.alibaba.service;

public interface StoreService {
    /**
     * 扣減庫存
     */
    void decrease(String commodityCode, Integer count);
}

新增 StoreService實作類 StoreServiceImpl類：

package com.younger.pcloud.alibaba.service.impl;

import com.younger.pcloud.alibaba.dao.StoreDao;
import com.younger.pcloud.alibaba.service.StoreService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;

@Service
@Slf4j
public class StoreServiceImpl implements StoreService {

    @Resource
    private StoreDao storeDao;

    @Override
    public void decrease(String commodityCode, Integer count) {
        log.info("storage-service-------中扣減庫存開始");
        storeDao.decrease(commodityCode,count);
        log.info("storage-service--------中扣減庫存結束");

    }
}

新增controller 包：

新增 StoreController 類：

package com.younger.pcloud.alibaba.controller;

import com.younger.pcloud.alibaba.domain.Result;
import com.younger.pcloud.alibaba.service.StoreService;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.annotation.Resource;

@RestController
public class StoreController {

    @Resource
    private StoreService storeService;

    /**
     * 扣減庫存
     */
   @RequestMapping("/storage/decrease")
   public Result decrease(@RequestParam("commodityCode") String commodityCode, @RequestParam("count") Integer count) {
        storeService.decrease(commodityCode, count);
        return new Result(200,"庫存扣減成功！");
    }

}
建立modul pcloud-alibaba-seata-account-service9003

修改pom檔案：

<?xml version="1.0" encoding="UTF-8"?>

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>pcloud-alibaba</artifactId>
        <groupId>com.younger.pcloud.alibaba</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>pcloud-alibaba-seata-account-service9003</artifactId>

    <name>pcloud-alibaba-seata-account-service9003</name>

    <dependencies>
        <!--nacos-->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <!--seata-->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-seata</artifactId>
            <exclusions>
                <exclusion>
                    <artifactId>seata-all</artifactId>
                    <groupId>io.seata</groupId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>io.seata</groupId>
            <artifactId>seata-all</artifactId>
            <version>1.4.2</version>
        </dependency>
        <!--feign-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.0.0</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.37</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.1.10</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
    </dependencies>
</project>

新增 application.yml 檔案：

server:
  port: 9003

spring:
  application:
    name: seata-account-service
  cloud:
    alibaba:
      seata:
        #自定義事務組名稱需要與seata-server中的對應
        tx-service-group: my_test_tx_group
    nacos:
      discovery:
        server-addr: localhost:8848
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/seata_account
    username: root
    password: mysql

feign:
  hystrix:
    enabled: false

logging:
  level:
    io:
      seata: info

mybatis:
  mapperLocations: classpath:mapper/*.xml

新增啟動類SeataAccountServiceMain9003：

package com.younger.pcloud.alibaba;


import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.openfeign.EnableFeignClients;

@EnableDiscoveryClient
@EnableFeignClients
@SpringBootApplication(exclude = DataSourceAutoConfiguration.class)
@EnableAutoDataSourceProxy
public class SeataAccountServiceMain9003 {

    public static void main(String[] args) {
        SpringApplication.run(SeataAccountServiceMain9003.class,args);
    }
}

目錄結構：

SpringCloud Alibaba 九（Seata介紹二）

從9001 拷貝 config 目錄和registry.conf 到 9003

新增domain 包：

新增 Account 類：

package com.younger.pcloud.alibaba.domain;

public class Account {

    private Long id;

    private String userId;

    private Integer money;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getUserId() {
        return userId;
    }

    public void setUserId(String userId) {
        this.userId = userId;
    }

    public Integer getMoney() {
        return money;
    }

    public void setMoney(Integer money) {
        this.money = money;
    }
}

新增 Result 類：

package com.younger.pcloud.alibaba.domain;

public class Result<T> {

    private Integer code;
    private String  message;
    private T       data;
 	 public Result() {
       
    }
    public Result(Integer code, String message, T data) {
        this.code = code;
        this.message = message;
        this.data = data;
    }

    public Result(Integer code, String message) {
        this(code,message,null);
    }

    public Integer getCode() {
        return code;
    }

    public void setCode(Integer code) {
        this.code = code;
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    public T getData() {
        return data;
    }

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

新增dao包：

新增 AccountDao 類：

package com.younger.pcloud.alibaba.dao;

import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;

@Mapper
public interface AccountDao {

    /**
     * 扣減賬戶餘額
     */
    void decrease(@Param("userId") String userId, @Param("money") Integer money);

}

新增 AccountMapper.xml 檔案：

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >

<mapper namespace="com.younger.pcloud.alibaba.dao.AccountDao">
    <update id="decrease">
        UPDATE account
        SET
          money = money - #{money}
        WHERE
          user_id = #{userId};
    </update>
</mapper>

新增service 包：

新增 AccountService 類：

package com.younger.pcloud.alibaba.service;

import org.springframework.web.bind.annotation.RequestParam;

public interface AccountService {
    /**
     * 扣減賬戶餘額
     * @param userId 使用者id
     * @param money 金額
     */
    void decrease(@RequestParam("userId") String  userId, @RequestParam("money") Integer money);

}

新增 AccountService 的實作類AccountServiceImpl：

package com.younger.pcloud.alibaba.service.impl;

import com.younger.pcloud.alibaba.dao.AccountDao;
import com.younger.pcloud.alibaba.service.AccountService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;


@Service
@Slf4j
public class AccountServiceImpl implements AccountService {

    @Resource
    AccountDao accountDao;

    /**
     * 扣減賬戶餘額
     */
    @Override
    public void decrease(String userId, Integer money) {
        log.info("account-service--------中扣減賬戶餘額開始");
        accountDao.decrease(userId,money);
        log.info("account-service-------中扣減賬戶餘額結束");
    }
}

新增 controller包：

新增 AccountController 類：

package com.younger.pcloud.alibaba.controller;

import com.younger.pcloud.alibaba.domain.Result;
import com.younger.pcloud.alibaba.service.AccountService;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import javax.annotation.Resource;

@RestController
public class AccountController {

    @Resource
    private AccountService accountService;

    /**
     * 扣減賬戶餘額
     */
    @RequestMapping("/account/decrease")
    public Result decrease(@RequestParam("userId") String userId, @RequestParam("money") Integer money){
        accountService.decrease(userId,money);
        return new Result(200,"賬戶餘額扣減成功！");
    }
}

啟動項目測試：

SpringCloud Alibaba 九（Seata介紹二）
SpringCloud Alibaba 九（Seata介紹二）

通過日志，我們可以知道我們的事務已經注冊成功了。

建立訂單： http://localhost:9001/order/create

參數請求：

{
    "id":1,
    "userId":"1",
    "commodityCode":"1",
    "count":1,
    "money":55
}
SpringCloud Alibaba 九（Seata介紹二）

我們服務之間的調用已經成功了。

我們看下表的資料：

SpringCloud Alibaba 九（Seata介紹二）
SpringCloud Alibaba 九（Seata介紹二）
SpringCloud Alibaba 九（Seata介紹二）

表裡面的資料和我們預想的結果是一樣的。

我們現在沒有在我們的業務上面添加事務，我們測試一下逾時會怎麼樣？

我們修改我們的AccountServiceImpl類：

SpringCloud Alibaba 九（Seata介紹二）

可以看到我們在類上面添加了逾時異常。

我們重新開機下項目測試：

測試：

SpringCloud Alibaba 九（Seata介紹二）

此刻通路已經逾時了。

我們看下資料庫：

SpringCloud Alibaba 九（Seata介紹二）
SpringCloud Alibaba 九（Seata介紹二）
SpringCloud Alibaba 九（Seata介紹二）

可以看到，我們在已經建立了訂單，并且庫存已經抵扣了，但是使用者沒有支付成功。這個就是我們常見的分布式事務的問題。

我們在我們的業務類上面添加我們的分布式注解：@GlobalTransactional

我們修改 OrderServiceImpl類:

SpringCloud Alibaba 九（Seata介紹二）

隻需要在我們的業務類上添加一個 @GlobalTransactional注解即可，這個name是我們自己定義的，但是需要全局唯一。

我們重新啟動項目看下：

測試：

SpringCloud Alibaba 九（Seata介紹二）

執行也是逾時的，我們在看下資料庫：

SpringCloud Alibaba 九（Seata介紹二）
SpringCloud Alibaba 九（Seata介紹二）
SpringCloud Alibaba 九（Seata介紹二）

我們看到訂單和庫存都沒有記錄。說明我們的分布式事務已經成功了。

總結一下分布式事務的執行流程：

1、TM 開啟分布式事務（TM 向 TC 注冊全局事務記錄）。

2、RM 向 TC 彙報資源準備狀态。

3、TM 通知 TC 送出/復原分布式事務。

4、TC 彙總事務資訊，決定分布式事務是送出還是復原。

5、TC 通知所有 RM 送出/復原 資源，事務二階段結束。

springcloud alibaba spring
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