Spring Cloud 整合 seata 实现分布式事务

伴随着越来越多的项目使用微服务架构或者把原来的单体应用改造为微服务，每个微服务都有自己的数据库后，分布式事务就是我们必须要考虑的问题了。

阿里巴巴开源的seata就是我们很好的一个选择。
优点：

• 开源
• 非侵入式的，微服务配置好以后，一个注解即可开启分布式事务。

1. 版本

框架	版本
Spring Cloud	Greenwich.RELEASE
Spring boot	2.1.4.RELEASE
Spring Cloud Alibaba	2.1.0.RELEASE
nacos	1.1.4
seata	1.1.0

2. 部署nacos

我习惯使用docker来部署应用，第一个是部署方便，第二个是删除方便。
这里主要讲下命令里面的--env MODE=standalone，表示nacos以单机模式启动。

docker run --env MODE=standalone --name nacos -d -p 8848:8848 nacos/nacos-server:1.1.4

启动成功后我们就可以访问nacos的网页。
地址：localhost:8848/nacos

输入nacos的默认账号和密码：nacos
注意username和password是一样的。

如果大家觉得默认密码不安全，大家可以点击右上角修改密码。

3. 部署seata

这里我还是用docker部署的，其实直接下载压缩包运行会更简单方便点，但是个人更喜欢用docker进行部署。

3.1 运行镜像

这里主要讲下命令中的-e SEATA_IP=127.0.0.1，表示指定seata-server启动的IP, 该IP用于向注册中心注册时使用, 如eureka等。如果大家跟我一样是部署在云服务器的话，就把“127.0.0.1”改为“你的云服务器公网IP”。

docker run -d --name seata-server -p 8091:8091 -e SEATA_IP=127.0.0.1 --net=host seataio/seata-server:1.1.0

3.2 配置seata

大家如果有看过seata官网文档就知道，seata默认是使用file的注册和配置模式。

在这里我们需要把其改为nacos的注册和配置模式。

① 我们使用docker cp命令，将容器中的配置文件拷贝出来。

docker cp seata-server:/seata-server/resources ~/seata-script

② 进入到seata-script文件夹

cd ~/seata-script

③ 修改file.conf

vim file.conf

大家可以对比着修改，或者直接复制过去替换掉。
注意，需要根据自己的环境修改url，user，password

## transaction log store, only used in seata-server
store {
  ## store mode: file、db
  mode = "db"

  ## file store property
  file {
    ## store location dir
    dir = "sessionStore"
    # branch session size , if exceeded first try compress lockkey, still exceeded throws exceptions
    maxBranchSessionSize = 16384
    # globe session size , if exceeded throws exceptions
    maxGlobalSessionSize = 512
    # file buffer size , if exceeded allocate new buffer
    fileWriteBufferCacheSize = 16384
    # when recover batch read size
    sessionReloadReadSize = 100
    # async, sync
    flushDiskMode = async
  }

  ## database store property
  db {
    ## the implement of javax.sql.DataSource, such as DruidDataSource(druid)/BasicDataSource(dbcp) etc.
    datasource = "druid"
    ## mysql/oracle/postgresql/h2/oceanbase etc.
    dbType = "mysql"
    driverClassName = "com.mysql.jdbc.Driver"
    url = "jdbc:mysql://127.0.0.1:3306/seata-seata"
    user = "root"
    password = "123456"
    minConn = 5
    maxConn = 30
    globalTable = "global_table"
    branchTable = "branch_table"
    lockTable = "lock_table"
    queryLimit = 100
    maxWait = 5000
  }
}

④ 修改registry.conf文件

vim registry.conf

这里也是需要根据自己的环境修改一些配置。
比如nacos下的serverAddr等。
其实我这里也就修改了type配置为nacos，并修改相应的nacos的配置信息。

注意，这里其实官网配置文件是有一个坑的，就是nacos的application配置，旧值为seata-server，我们需要修改为serverAddr。

GitHub issue连接
截图如下：

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

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

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

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

3.4 把修改好的配置文件拷贝回seata容器

拷贝命令

docker cp registry.conf seata-server:/seata-server/resources
docker cp file.conf seata-server:/seata-server/resources

重启我们的seata-server容器

docker restart seata-server

3.5 通过脚本把配置信息传到nacos

我们还是在~/seata-script路径下，新建两个文件，分别为nacos-config.sh和config.txt。

① nacos-config.sh中的内容：

#!/usr/bin/env bash
# Copyright 1999-2019 Seata.io Group.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at、
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

while getopts ":h:p:g:t:" opt
do
  case $opt in
  h)
    host=$OPTARG
    ;;
  p)
    port=$OPTARG
    ;;
  g)
    group=$OPTARG
    ;;
  t)
    tenant=$OPTARG
    ;;
  ?)
    echo "\033[31m USAGE OPTION: $0 [-h host] [-p port] [-g group] [-t tenant] \033[0m"
    exit 1
    ;;
  esac
done

if [[ -z ${host} ]]; then
    host=localhost
fi
if [[ -z ${port} ]]; then
    port=8848
fi
if [[ -z ${group} ]]; then
    group="SEATA_GROUP"
fi
if [[ -z ${tenant} ]]; then
    tenant=""
fi

nacosAddr=$host:$port
contentType="content-type:application/json;charset=UTF-8"

echo "set nacosAddr=$nacosAddr"
echo "set group=$group"

failCount=0
tempLog=$(mktemp -u)
function addConfig() {
  curl -X POST -H "${1}" "http://$2/nacos/v1/cs/configs?dataId=$3&group=$group&content=$4&tenant=$tenant" >"${tempLog}" 2>/dev/null
  if [[ -z $(cat "${tempLog}") ]]; then
    echo "\033[31m Please check the cluster status. \033[0m"
    exit 1
  fi
  if [[ $(cat "${tempLog}") =~ "true" ]]; then
    echo "Set $3=$4\033[32m successfully \033[0m"
  else
    echo "Set $3=$4\033[31m failure \033[0m"
    (( failCount++ ))
  fi
}

count=0
for line in $(cat config.txt); do
  (( count++ ))
        key=${line%%=*}
  value=${line#*=}
        addConfig "${contentType}" "${nacosAddr}" "${key}" "${value}"
done

echo "========================================================================="
echo " Complete initialization parameters, \033[32m total-count:$count \033[0m, \033[31m failure-count:$failCount \033[0m"
echo "========================================================================="

if [[ ${failCount} -eq 0 ]]; then
        echo "\033[32m Init nacos config finished, please start seata-server. \033[0m"
else
        echo "\033[31m init nacos config fail. \033[0m"
fi

② config.txt中的内容：

大家也要根据自己的环境进行相应的修改。

service.vgroupMapping.jamie_tx_group=default
store.mode=db
store.db.datasource=druid
store.db.dbType=mysql
store.db.driverClassName=com.mysql.jdbc.Driver
store.db.url=jdbc:mysql://127.0.0.1:3306/seata-server?useUnicode=true
store.db.user=root
store.db.password=123456

③ 我们执行脚本

sh nacos-config.sh

执行完后我们就可以在nacos中看到这些配置信息了

3.6 最后重启我们的seata容器就ok了

docker restart seata-server

执行完该命令后，我们的seata服务就部署好了。

接下来就可以构建我们的应用了

4. 构建Spring Cloud 应用

这里我们是使用feign作为RPC调用组件。

我们的整体的架构图如下，截取自seata官网：

4.1 创建父项目

创建完后，我们删除src文件夹。
配置pom.xml文件，内容如下：

<?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">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.jamie</groupId>
    <artifactId>spring-cloud-demo</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>pom</packaging>

    <!--    统一管理jar包版本    -->
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
        <lombok.version>1.18.6</lombok.version>
        <mybatis.plus.version>3.2.0</mybatis.plus.version>
        <swagger.version>2.9.2</swagger.version>
        <druid.version>1.1.10</druid.version>
        <spring.boot.version>2.1.4.RELEASE</spring.boot.version>
    </properties>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>${spring.boot.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Greenwich.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>2.1.0.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <optional>true</optional>
                <version>${lombok.version}</version>
            </dependency>
            <dependency>
                <groupId>com.baomidou</groupId>
                <artifactId>mybatis-plus-boot-starter</artifactId>
                <version>${mybatis.plus.version}</version>
            </dependency>
            <dependency>
                <groupId>io.springfox</groupId>
                <artifactId>springfox-swagger2</artifactId>
                <version>${swagger.version}</version>
            </dependency>
            <dependency>
                <groupId>io.springfox</groupId>
                <artifactId>springfox-swagger-ui</artifactId>
                <version>${swagger.version}</version>
            </dependency>
            <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>druid-spring-boot-starter</artifactId>
                <version>${druid.version}</version>
            </dependency>
        </dependencies>
    </dependencyManagement>
</project>

4.2 创建api模块

api模块是用于每个微服务共同使用的，减少我们编写重复的代码。

4.2.1 在父项目的文件夹，点击右键 -> New -> Module...

4.2.2 创建完成后，我们就有一个api模块了

4.2.3 修改api模块的pom.xml文件

<?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>spring-cloud-demo</artifactId>
        <groupId>com.jamie</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>api</artifactId>

    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-openfeign-core</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
    </dependencies>

</project>

4.2.4 编写我们的远程调用代码

• AccountService

import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;

/**
 * @author https://blog.youkuaiyun.com/qq_37170583
 * @date 2020/4/13
 */
@FeignClient("account")
@RequestMapping("account")
public interface AccountService {

    /**
     * 扣减账户余额
     *
     * @param userId 用户id
     * @param money  扣减金额
     */
    @PostMapping
    void debit(@RequestParam("userId") String userId, @RequestParam("money") int money);
}

• OrderService

import com.jamie.api.dto.OrderDTO;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;

/**
 * @author https://blog.youkuaiyun.com/qq_37170583
 * @date 2020/4/13
 */
@FeignClient("order")
@RequestMapping("order")
public interface OrderService {

    /**
     * 创建订单
     *
     * @param userId        用户id
     * @param commodityCode 商品编码
     * @param orderCount    购买数量
     * @return 订单
     */
    @PostMapping
    OrderDTO create(@RequestParam("userId") String userId,
                    @RequestParam("commodityCode") String commodityCode,
                    @RequestParam("orderCount") int orderCount);
}

import lombok.Data;

import java.io.Serializable;

/**
 * @author https://blog.youkuaiyun.com/qq_37170583
 * @date 2020/4/13
 */
@Data
public class OrderDTO implements Serializable {
    private Long id;
    private String userId;
    private String commodityCode;
    private Integer count;
    private Integer money;
}

• StorageService

import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;

/**
 * @author https://blog.youkuaiyun.com/qq_37170583
 * @date 2020/4/13
 */
@FeignClient("storage")
@RequestMapping("storage")
public interface StorageService {
    /**
     * 扣减库存
     *
     * @param commodityCode 商品编码
     * @param count         扣减数量
     */
    @PostMapping
    void deduct(@RequestParam("commodityCode") String commodityCode, @RequestParam("count") int count);
}

4.2.5 最后我们执行下maven install，将api模块安装到本地的maven仓库。

4.3 编写business模块的代码

4.3.1 同api模块一样，先创建business模块

整体文件结构如下：

4.3.2 配置pom.xml

<?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>spring-cloud-demo</artifactId>
        <groupId>com.jamie</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>business</artifactId>

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

        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>

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

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

        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger2</artifactId>
        </dependency>

        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger-ui</artifactId>
        </dependency>

        <dependency>
            <groupId>com.jamie</groupId>
            <artifactId>api</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>

        <!-- seata-->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-alibaba-seata</artifactId>
        </dependency>
        <dependency>
            <groupId>io.seata</groupId>
            <artifactId>seata-all</artifactId>
            <version>1.1.0</version>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <fork>true</fork>
                    <addResources>true</addResources>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

4.3.3 创建application.properties文件并进行配置

注意，这里要根据自己的环境修改spring.cloud.nacos.discovery.server-addr配置

server.port=10000
spring.application.name=business

spring.cloud.nacos.discovery.server-addr=127.0.0.1:8848

##############    seata配置    ##############
spring.cloud.alibaba.seata.tx-service-group=jamie_tx_group

ribbon.ReadTimeout=60000
ribbon.ConnectTimeout=60000

4.3.4 创建registry.conf文件

注意，这里要根据自己的环境修改serverAddr配置

registry {
  type = "nacos"

  nacos {
    serverAddr = "127.0.0.1"
    namespace = ""
    cluster = "default"
  }
}

config {
  type = "nacos"

  nacos {
    serverAddr = "127.0.0.1"
    namespace = ""
    group = "SEATA_GROUP"
  }
}

4.3.5 编写Spring boot 启动类

import io.seata.spring.annotation.datasource.EnableAutoDataSourceProxy;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.openfeign.EnableFeignClients;

/**
 * @author Jamie
 * @date 2020/4/13
 */
@EnableAutoDataSourceProxy
@EnableFeignClients("com.jamie")
@EnableDiscoveryClient
@SpringBootApplication
public class BusinessApplication {
    public static void main(String[] args) {
        SpringApplication.run(BusinessApplication.class, args);
    }
}

4.3.6 编写业务类

① service类

/**
 * @author Jamie
 * @date 2020/4/13
 */
public interface BusinessService {
    /**
     * 采购
     *
     * @param userId        用户id
     * @param commodityCode 商品编码
     * @param orderCount    购买数量
     */
    void purchase(String userId, String commodityCode, int orderCount);
}

注意，这个@GlobalTransactional注解就是用于开启全局事务。

import com.jamie.api.order.OrderService;
import com.jamie.api.storage.StorageService;
import com.jamie.business.service.BusinessService;
import io.seata.spring.annotation.GlobalTransactional;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;

/**
 * @author Jamie
 * @date 2020/4/13
 */
@Service
public class BusinessServiceImpl implements BusinessService {
    @Resource
    private StorageService storageService;
    @Resource
    private OrderService orderService;

    @GlobalTransactional
    @Override
    public void purchase(String userId, String commodityCode, int orderCount) {
        storageService.deduct(commodityCode, orderCount);
        orderService.create(userId, commodityCode, orderCount);
    }
}

② controller类

import com.jamie.business.service.BusinessService;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import javax.annotation.Resource;

/**
 * @author Jamie
 * @date 2020/4/13
 */
@RestController
public class BusinessController {

    @Resource
    private BusinessService businessService;

    @PostMapping("purchase")
    public String purchase(@RequestParam("userId") String userId,
                           @RequestParam("commodityCode") String commodityCode,
                           @RequestParam("orderCount") int orderCount) {
        businessService.purchase(userId, commodityCode, orderCount);
        return "ok";
    }
}

4.4 编写order模块的代码

其实order模块，storage模块和account模块的配置和代码都一样。
这里我就只写一个order模块作为例子，其它请参照模仿即可。

4.4.1 配置pom.xml文件

<?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>spring-cloud-demo</artifactId>
        <groupId>com.jamie</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>order</artifactId>

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

        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>

        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
        </dependency>

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

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
        </dependency>

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

        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger2</artifactId>
        </dependency>

        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger-ui</artifactId>
        </dependency>

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

        <dependency>
            <groupId>cn.hutool</groupId>
            <artifactId>hutool-all</artifactId>
            <version>5.2.5</version>
        </dependency>

        <dependency>
            <groupId>com.jamie</groupId>
            <artifactId>api</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>

        <!-- seata-->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-alibaba-seata</artifactId>
        </dependency>
        <dependency>
            <groupId>io.seata</groupId>
            <artifactId>seata-all</artifactId>
            <version>1.1.0</version>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <version>2.2.6.RELEASE</version>
                <configuration>
                    <fork>true</fork>
                    <addResources>true</addResources>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

4.4.2 创建application.properties文件

大家这里也是根据自己的环境修改相应的配置

server.port=10001
spring.application.name=order

# 数据源配置
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.url=jdbc:mysql://127.0.0.1:3306/seata-order?useUnicode=true&characterEncoding=UTF-8&useSSL=false&serverTimezone=GMT%2B8
spring.datasource.username=root
spring.datasource.password=123456

spring.cloud.nacos.discovery.server-addr=127.0.0.1:8848

mybatis-plus.configuration.map-underscore-to-camel-case=true
#id自动生成策略
mybatis-plus.global-config.db-config.id-type=auto

##############    seata配置    ##############
spring.cloud.alibaba.seata.tx-service-group=jamie_tx_group

ribbon.ReadTimeout=60000
ribbon.ConnectTimeout=60000

4.4.3 创建registry.conf文件

注意，这里要根据自己的环境修改serverAddr配置

registry {
  type = "nacos"

  nacos {
    serverAddr = "127.0.0.1"
    namespace = ""
    cluster = "default"
  }
}

config {
  type = "nacos"

  nacos {
    serverAddr = "127.0.0.1"
    namespace = ""
    group = "SEATA_GROUP"
  }
}

4.4.4 编写Spring boot 启动类代码

import com.jamie.api.account.AccountService;
import io.seata.spring.annotation.datasource.EnableAutoDataSourceProxy;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.openfeign.EnableFeignClients;

/**
 * @author Jamie
 * @date 2020/3/29
 */
@EnableAutoDataSourceProxy
@EnableFeignClients(clients = AccountService.class)
@EnableDiscoveryClient
@SpringBootApplication
public class OrderApplication {
    public static void main(String[] args) {
        SpringApplication.run(OrderApplication.class, args);
    }
}

4.4.5 编写业务代码

• service类

import cn.hutool.core.bean.BeanUtil;
import com.jamie.api.account.AccountService;
import com.jamie.api.dto.OrderDTO;
import com.jamie.api.order.OrderService;
import com.jamie.order.domain.Order;
import com.jamie.order.mapper.OrderMapper;
import org.springframework.web.bind.annotation.RestController;

import javax.annotation.Resource;
import java.util.HashMap;
import java.util.Map;

/**
 * @author Jamie
 * @date 2020/3/31
 */
@RestController
public class OrderServiceImpl implements OrderService {
    @Resource
    private OrderMapper orderMapper;

    @Resource
    private AccountService accountService;

    private static final Map<String, Integer> COMMODITY_PRICE;

    static {
        COMMODITY_PRICE = new HashMap<>();
        COMMODITY_PRICE.put("product-1", 2);
        COMMODITY_PRICE.put("product-2", 3);
    }

    @Override
    public OrderDTO create(String userId, String commodityCode, int orderCount) {
        int orderMoney = calculate(commodityCode, orderCount);

        accountService.debit(userId, orderMoney);

        Order order = new Order();
        order.setUserId(userId);
        order.setCommodityCode(commodityCode);
        order.setCount(orderCount);
        order.setMoney(orderMoney);

        // INSERT INTO orders ...
        orderMapper.insert(order);
        if ("product-1".equals(commodityCode)) {
            throw new RuntimeException("故意抛出异常，测试seata");
        }
        return BeanUtil.copyProperties(order, OrderDTO.class);
    }

    private int calculate(String commodityCode, int orderCount) {
        return orderCount * COMMODITY_PRICE.get(commodityCode);
    }
}

• mapper 类

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.jamie.order.domain.Order;
import org.apache.ibatis.annotations.Mapper;

/**
 * @author Jamie
 * @date 2020/3/31
 */
@Mapper
public interface OrderMapper extends BaseMapper<Order> {
}

• domain类

import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.Data;

/**
 * @author Jamie
 * @date 2020/4/13
 */
@Data
@TableName("`order`")
public class Order {
    private Long id;
    private String userId;
    private String commodityCode;
    @TableField("`count`")
    private Integer count;
    private Integer money;
}

• config类
  主要用于打印feign调用的日志，可以不写。

import feign.Logger;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

/**
 * @author Jamie
 * @date 2020/4/1
 */
@Configuration
public class FeignLevelConfig {

    @Bean
    public Logger.Level feignLogLevel() {
        return Logger.Level.BASIC;
    }
}

4.5 其它两个微服务的代码

• account模块

import com.jamie.account.domain.Account;
import com.jamie.account.mapper.AccountMapper;
import com.jamie.api.account.AccountService;
import org.springframework.web.bind.annotation.RestController;

import javax.annotation.Resource;

/**
 * @author Jamie
 * @date 2020/4/13
 */
@RestController
public class AccountServiceImpl implements AccountService {
    @Resource
    private AccountMapper accountMapper;

    @Override
    public void debit(String userId, int money) {
        Account account = new Account();
        account.setUserId(userId);
        account.setMoney(money);
        accountMapper.insert(account);
    }
}

• storage模块

import com.baomidou.mybatisplus.core.conditions.update.LambdaUpdateWrapper;
import com.jamie.api.storage.StorageService;
import com.jamie.storage.domain.Storage;
import com.jamie.storage.mapper.StorageMapper;
import org.springframework.web.bind.annotation.RestController;

import javax.annotation.Resource;

/**
 * @author Jamie
 * @date 2020/4/13
 */
@RestController
public class StorageServiceImpl implements StorageService {
    @Resource
    private StorageMapper storageMapper;

    @Override
    public void deduct(String commodityCode, int count) {
        LambdaUpdateWrapper<Storage> wrapper = new LambdaUpdateWrapper<>();
        wrapper.ge(Storage::getCount, count);
        wrapper.eq(Storage::getCommodityCode, commodityCode);
        wrapper.setSql("count = count - " + count);
        int updateCount = storageMapper.update(null, wrapper);
        if (updateCount == 0) {
            throw new RuntimeException("库存不足，扣减失败");
        }
    }
}

5 准备我们的数据库

5.1 准备seata-server数据库

-- -------------------------------- The script used when storeMode is 'db' --------------------------------
-- the table to store GlobalSession data
CREATE TABLE IF NOT EXISTS `global_table`
(
    `xid`                       VARCHAR(128) NOT NULL,
    `transaction_id`            BIGINT,
    `status`                    TINYINT      NOT NULL,
    `application_id`            VARCHAR(32),
    `transaction_service_group` VARCHAR(32),
    `transaction_name`          VARCHAR(128),
    `timeout`                   INT,
    `begin_time`                BIGINT,
    `application_data`          VARCHAR(2000),
    `gmt_create`                DATETIME,
    `gmt_modified`              DATETIME,
    PRIMARY KEY (`xid`),
    KEY `idx_gmt_modified_status` (`gmt_modified`, `status`),
    KEY `idx_transaction_id` (`transaction_id`)
) ENGINE = InnoDB
  DEFAULT CHARSET = utf8;

-- the table to store BranchSession data
CREATE TABLE IF NOT EXISTS `branch_table`
(
    `branch_id`         BIGINT       NOT NULL,
    `xid`               VARCHAR(128) NOT NULL,
    `transaction_id`    BIGINT,
    `resource_group_id` VARCHAR(32),
    `resource_id`       VARCHAR(256),
    `branch_type`       VARCHAR(8),
    `status`            TINYINT,
    `client_id`         VARCHAR(64),
    `application_data`  VARCHAR(2000),
    `gmt_create`        DATETIME(6),
    `gmt_modified`      DATETIME(6),
    PRIMARY KEY (`branch_id`),
    KEY `idx_xid` (`xid`)
) ENGINE = InnoDB
  DEFAULT CHARSET = utf8;

-- the table to store lock data
CREATE TABLE IF NOT EXISTS `lock_table`
(
    `row_key`        VARCHAR(128) NOT NULL,
    `xid`            VARCHAR(96),
    `transaction_id` BIGINT,
    `branch_id`      BIGINT       NOT NULL,
    `resource_id`    VARCHAR(256),
    `table_name`     VARCHAR(32),
    `pk`             VARCHAR(36),
    `gmt_create`     DATETIME,
    `gmt_modified`   DATETIME,
    PRIMARY KEY (`row_key`),
    KEY `idx_branch_id` (`branch_id`)
) ENGINE = InnoDB
  DEFAULT CHARSET = utf8;

5.2 准备order数据库

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',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

CREATE TABLE `undo_log` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT 'increment id',
  `branch_id` bigint(20) NOT NULL COMMENT 'branch transaction id',
  `xid` varchar(100) 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 NOT NULL COMMENT 'create datetime',
  `log_modified` datetime NOT NULL COMMENT 'modify datetime',
  PRIMARY KEY (`id`),
  UNIQUE KEY `ux_undo_log` (`xid`,`branch_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

5.3 准备storage数据库

CREATE TABLE `storage` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `commodity_code` varchar(255) DEFAULT NULL,
  `count` int(11) DEFAULT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `commodity_code` (`commodity_code`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

INSERT INTO `seata-storage`.`storage`(`id`, `commodity_code`, `count`) VALUES (1, 'product-1', 10);
INSERT INTO `seata-storage`.`storage`(`id`, `commodity_code`, `count`) VALUES (2, 'product-2', 5);

CREATE TABLE `undo_log` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT 'increment id',
  `branch_id` bigint(20) NOT NULL COMMENT 'branch transaction id',
  `xid` varchar(100) 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 NOT NULL COMMENT 'create datetime',
  `log_modified` datetime NOT NULL COMMENT 'modify datetime',
  PRIMARY KEY (`id`),
  UNIQUE KEY `ux_undo_log` (`xid`,`branch_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

5.4 准备account数据库

CREATE TABLE `account` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `user_id` varchar(255) DEFAULT NULL,
  `money` int(11) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

CREATE TABLE `undo_log` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT 'increment id',
  `branch_id` bigint(20) NOT NULL COMMENT 'branch transaction id',
  `xid` varchar(100) 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 NOT NULL COMMENT 'create datetime',
  `log_modified` datetime NOT NULL COMMENT 'modify datetime',
  PRIMARY KEY (`id`),
  UNIQUE KEY `ux_undo_log` (`xid`,`branch_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

6 启动4个项目，测试我们的分布式事务

打开nacos的服务列表，我们可以看到所有服务都已经注册成功。

6.1 首先我们测试正确的情况

使用postman输入地址：localhost:10000/purchase?userId=jam&commodityCode=product-2&orderCount=1

我们可以看到，返回了ok。

然后我们再去查看数据库的情况，也成功保存了数据。

6.2 现在我们测试下分布式事务回滚的情况

我们修改请求参数的commodityCode为product-1，然后发起请求

可以看到，返回的是错误信息。

然后我们看下数据库的情况，数据没有发生变化。



说明我们的分布式事务起作用了，没有发生数据不一致的情况，大功告成。

源码地址：码云