分布式事务框架--Seata(AT模式)--SpringCloud--使用/教程/实例

心已赠人 2023-10-02 14:57 19阅读 0赞

原文网址：[分布式事务框架--Seata(AT模式)--SpringCloud--使用/教程/实例\_IT利刃出鞘的博客-CSDN博客][--Seata_AT_--SpringCloud--_IT_-CSDN]

## 简介 ##

**说明**

本文用示例介绍分布式事务框架Seata的AT模式的用法。

Seata是阿里的分布式事务框架，支持SpringCloud、Dubbo，本文使用SpringCoud进行展示。

之前测试Seata AT模式时，有一些问题，所以本处使用新版本（官方说已经解决此问题）。旧Seata AT模式的网址：[这里][Link 1]

**官网**

[Seata部署指南][Seata]

**业务场景**

创建订单时，order微服务先预生成订单（订单状态为创建中），再调用storage的feign来减库存，再调用account的feign来减账户余额，最后将订单状态改为已完成。

**技术栈：**

*  spring-cloud-starter-alibaba-seata:2.2.3.RELEASE
 *  seata-spring-boot-starter:1.4.1
 *  springboot:2.3.7.RELEASE
 *  springcloud:Hoxton.SR9
 *  mysql
 *  mybatis-plus-boot-starter:3.4.1
 *  eureka
 *  gateway

**配置方式**

*  seata-server: file.conf, registry.conf
 *  业务微服务服务：application.yml

**重大改变**

引入Seata之后，如果不使用@GlobalTransactional而调用feign不会再报“xid must not be blank”错误。

## seata-server安装/配置 ##

**下载seata服务**

[https://github.com/seata/seata/releases][https_github.com_seata_seata_releases]

**配置**

本处使用mysql、eureka，未使用配置中心。

修改的文件：seata-server-1.4.0\\seata\\conf\\ file.cof、registry.conf

file.conf //配置事务的存储方式。改动点已经加粗。

\#\# transaction log store, only used in seata-server  
store \{  
\#\# store mode: file、db、redis  
\# mode = "file"  
**mode = "db"** \#将事务信息存到数据库中。配置为"db"时，只有“db”节点下的配置有效，不用管“file”

\#\# 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)/HikariDataSource(hikari) 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"  
\#\# user = "mysql"  
\#\# password = "mysql"  
**driverClassName = "com.mysql.cj.jdbc.Driver"** \#使用mysql8.x驱动  
 **url: "jdbc:mysql://127.0.0.1:3306/seata?useUnicode=true&characterEncoding=utf8&useSSL=false&serverTimezone=GMT%2B8"** \#指定服务器地址及数据库等  
 **user = "xxx"  
password = "xxx"**  
minConn = 5  
maxConn = 100  
globalTable = "global\_table"  
branchTable = "branch\_table"  
lockTable = "lock\_table"  
queryLimit = 100  
maxWait = 5000  
\}

\#\# redis store property  
redis \{  
host = "127.0.0.1"  
port = "6379"  
password = ""  
database = "0"  
minConn = 1  
maxConn = 10  
maxTotal = 100  
queryLimit = 100  
\}

registry.conf //配置注册中心。改动点已经加粗。

registry \{  
\# file 、nacos 、eureka、redis、zk、consul、etcd3、sofa  
\#type = "file"  
**type = "eureka"**  
  
loadBalance = "RandomLoadBalance"  
loadBalanceVirtualNodes = 10

nacos \{  
application = "seata-server"  
serverAddr = "127.0.0.1:8848"  
group = "SEATA\_GROUP"  
namespace = ""  
cluster = "default"  
username = ""  
password = ""  
\}  
eureka \{  
\# serviceUrl = "http://localhost:8761/eureka"  
**serviceUrl = "http://localhost:7001/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 = "file"

nacos \{  
serverAddr = "127.0.0.1:8848"  
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"  
apolloAccesskeySecret = ""  
\}  
zk \{  
serverAddr = "127.0.0.1:2181"  
sessionTimeout = 6000  
connectTimeout = 2000  
username = ""  
password = ""  
\}  
etcd3 \{  
serverAddr = "http://localhost:2379"  
\}  
file \{  
name = "file.conf"  
\}  
\}

## 建库建表 ##

### seata的库表 ###

**创建数据库**

创建名为seata的数据库。

**seata服务事务表**

全局事务会话信息由3块内容构成，全局事务-->分支事务-->全局锁，对应表global\_table、branch\_table、lock\_table。

在上边**file.conf**指定的数据库里创建如下表：

//有人说这些语句在seata-server-xxx/conf/db\_store.sql里。但我没找到，可能新的seata-server已经没有了。

-- -------------------------------- 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;

**业务事务表**

每个被调用的服务以及服务的调用方都需要用到 "undo\_log"表用于事务的回滚。新版本只需创建一个这个表即可（如果是单个数据库，所有微服务共用这一个表；如果是多个数据库，需要每个数据库创建一个这个表）

-- 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(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(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 = utf8 COMMENT ='AT transaction mode undo table';

### **业务库表** ###

CREATE TABLE `t_order` (
      `id` bigint(11) NOT NULL AUTO_INCREMENT,
      `user_id` bigint(11) DEFAULT NULL COMMENT '用户id',
      `product_id` bigint(11) DEFAULT NULL COMMENT '产品id',
      `count` int(11) DEFAULT NULL COMMENT '数量',
      `money` decimal(11,0) DEFAULT NULL COMMENT '金额',
      `status` int(1) DEFAULT NULL COMMENT '订单状态：0：创建中；1：已完结',
      `create_time` datetime(0) NULL DEFAULT NULL,
      `update_time` datetime(0) NULL DEFAULT NULL ON UPDATE CURRENT_TIMESTAMP(0),
      PRIMARY KEY (`id`)
    ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT '订单';

踩坑：其他教程表名是"order"，我用mybatis-plus时，会报错。因为，它插入数据时语句是：INSERT INTO order ...，表名没有用\`\`包裹，而order是mysql关键字，所以报错。

CREATE TABLE `t_account` (
      `id` bigint(11) NOT NULL AUTO_INCREMENT COMMENT 'id',
      `user_id` bigint(11) DEFAULT NULL COMMENT '用户id',
      `total` decimal(10,0) DEFAULT NULL COMMENT '总额度',
      `used` decimal(10,0) DEFAULT NULL COMMENT '已用余额',
      `residue` decimal(10,0) DEFAULT '0' COMMENT '剩余可用额度',
      `create_time` datetime(0) NULL DEFAULT NULL,
      `update_time` datetime(0) NULL DEFAULT NULL ON UPDATE CURRENT_TIMESTAMP(0),
      PRIMARY KEY (`id`)
    ) ENGINE=InnoDBDEFAULT CHARSET=utf8 COMMENT '账户';
    
    INSERT INTO `demo`.`t_account` (`id`, `user_id`, `total`, `used`, `residue`) VALUES ('1', '1', '1000', '0', '1000');

CREATE TABLE `t_storage` (
      `id` bigint(11) NOT NULL AUTO_INCREMENT,
      `product_id` bigint(11) DEFAULT NULL COMMENT '产品id',
      `total` int(11) DEFAULT NULL COMMENT '总库存',
      `used` int(11) DEFAULT NULL COMMENT '已用库存',
      `residue` int(11) DEFAULT NULL COMMENT '剩余库存',
      `create_time` datetime(0) NULL DEFAULT NULL,
      `update_time` datetime(0) NULL DEFAULT NULL ON UPDATE CURRENT_TIMESTAMP(0),
      PRIMARY KEY (`id`)
    ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT '库存';
    
    INSERT INTO `demo`.`t_storage` (`id`, `product_id`, `total`, `used`, `residue`) VALUES ('1', '1', '100', '0', '100');

## 业务微服务配置Seata ##

**order/storage/account**

这三个微服务都用这种配置。只有一处是不同的：seata.application-id。

application.yml

seata:  
enabled: true  
**application-id: order\_seata**  
tx-service-group: my\_tx\_group  
enable-auto-data-source-proxy: true  
service:  
vgroup-mapping:  
my\_tx\_group: default \# key与上面的tx-service-group的值对应  
registry:  
type: eureka  
eureka:  
application: default  
service-url: http://localhost:7001/eureka  
weight: 1  
\# config:  
\# type: nacos  
\# nacos:  
\# namespace:  
\# serverAddr: 127.0.0.1:8848  
\# group: SEATA\_GROUP  
\# username: "nacos"  
\# password: "nacos"

## 业务主要代码 ##

### order ###

**controller**

package com.example.order.controller;
    
    import com.example.order.entity.Order;
    import com.example.order.service.OrderService;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.PostMapping;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    @RestController
    @RequestMapping("/order")
    public class OrderController {
        @Autowired
        OrderService orderService;
    
        //使用Seata
        @PostMapping("create")
        public String create(Order order) {
            orderService.create(order);
            return "success";
        }
    
        //不使用Seata的
        @PostMapping("createNoSeata")
        public String createNoSeata(Order order) {
            orderService.createNoSeata(order);
            return "success";
        }
    
        // 在另一个微服务里再调用feign
        @PostMapping("create2")
        public String create2(Order order) {
            orderService.create2(order);
            return "success";
        }
    }

**service**

Service

package com.example.order.service;
    
    import com.baomidou.mybatisplus.extension.service.IService;
    import com.example.order.entity.Order;
    
    public interface OrderService extends IService<Order> {
        void create(Order order);
    
        void createNoSeata(Order order);
    
        void create2(Order order);
    }

ServiceImpl

package com.example.order.service.impl;
    
    import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
    import com.example.base.feign.AccountFeignClient;
    import com.example.base.feign.StorageFeignClient;
    import com.example.order.entity.Order;
    import com.example.order.mapper.OrderMapper;
    import com.example.order.service.OrderService;
    import io.seata.spring.annotation.GlobalTransactional;
    import lombok.extern.slf4j.Slf4j;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Service;
    import org.springframework.transaction.annotation.Transactional;
    
    @Slf4j
    @Service
    public class OrderServiceImpl extends ServiceImpl<OrderMapper, Order> implements OrderService {
        @Autowired
        StorageFeignClient storageFeignClient;
    
        @Autowired
        AccountFeignClient accountFeignClient;
    
        //  AT模式
        @Override
        @GlobalTransactional(name = "my_tx_group",rollbackFor = Exception.class)
        public void create(Order order) {
            log.info("--创建订单开始 （创建并冻结）");
            order.setStatus(0);
            save(order);
            log.info("--创建订单结束（创建并冻结成功");
    
            log.info("--扣减库存开始");
            storageFeignClient.decreaseStorage(order.getProductId(), order.getCount());
            log.info("--扣减库存结束");
    
    //        int i = 1/0;
    
            log.info("--扣减账户余额开始");
            accountFeignClient.decreaseMoney(order.getUserId(), order.getMoney());
            log.info("--扣减账户余额结束");
    
            this.getBaseMapper().updateStatus(order.getId(), 1);
    
    //        int i = 1/0;
        }
    
        @Override
        @Transactional
        public void createNoSeata(Order order) {
            log.info("--创建订单开始 （创建并冻结）");
            order.setStatus(0);
            save(order);
            log.info("--创建订单结束（创建并冻结成功");
    
            log.info("--扣减库存开始");
            storageFeignClient.decreaseStorage(order.getProductId(), order.getCount());
            log.info("--扣减库存结束");
    
    //        int i = 1/0;
    
            log.info("--扣减账户余额开始");
            accountFeignClient.decreaseMoney(order.getUserId(), order.getMoney());
            log.info("--扣减账户余额结束");
    
            this.getBaseMapper().updateStatus(order.getId(), 1);
    
    //        int i = 1/0;
        }
    
        @Override
        @GlobalTransactional(name = "my_tx_group",rollbackFor = Exception.class)
        public void create2(Order order) {
            log.info("--创建订单开始 （创建并冻结）");
            order.setStatus(0);
            save(order);
            log.info("--创建订单结束（创建并冻结成功");
    
            log.info("--扣减库存和余额开始");
            storageFeignClient.decreaseStorageAndMoney(order.getProductId(), order.getCount(),
                    order.getUserId(), order.getMoney());
            log.info("--扣减库存和余额结束");
    
            int i = 1/0;
    
            this.getBaseMapper().updateStatus(order.getId(), 1);
    
    //        int i = 1/0;
        }
    }

**mapper**

package com.example.order.mapper;
    
    import com.baomidou.mybatisplus.core.mapper.BaseMapper;
    import com.example.order.entity.Order;
    import org.apache.ibatis.annotations.Param;
    import org.apache.ibatis.annotations.Update;
    import org.springframework.stereotype.Repository;
    
    @Repository
    public interface OrderMapper extends BaseMapper<Order> {
        @Update("UPDATE `t_order` SET status = #{status} WHERE id = #{id}")
        int updateStatus(@Param("id") Long id, @Param("status") Integer status);
    }

### storage ###

**controller**

package com.example.storage.feign;
    
    import com.example.storage.service.StorageService;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.PostMapping;
    import org.springframework.web.bind.annotation.RequestParam;
    import org.springframework.web.bind.annotation.RestController;
    
    import java.math.BigDecimal;
    
    @RestController
    public class FeignController {
        @Autowired
        StorageService storageService;
    
        @PostMapping("/feign/storage/decreaseStorage")
        public void decreaseStorage(@RequestParam("productId")Long productId, @RequestParam("count")Integer count) {
            storageService.decreaseStorage(productId, count);
        }
    
        @PostMapping("/feign/storage/decreaseStorageAndMoney")
        public void decreaseStorage(@RequestParam("productId")Long productId, @RequestParam("count")Integer count,
                                    @RequestParam("userId")Long userId, @RequestParam("money") BigDecimal money) {
            storageService.decreaseStorageAndMoney(productId, count, userId, money);
        }
    }

**service**

Service

package com.example.storage.service;
    
    import com.baomidou.mybatisplus.extension.service.IService;
    import com.example.storage.entity.Storage;
    
    import java.math.BigDecimal;
    
    public interface StorageService extends IService<Storage> {
        void decreaseStorage(Long productId, Integer count);
    
        void decreaseStorageAndMoney(Long productId, Integer count, Long userId, BigDecimal money);
    }

ServiceImpl

package com.example.storage.service.impl;
    
    import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
    import com.example.storage.entity.Storage;
    import com.example.storage.mapper.StorageMapper;
    import com.example.storage.service.StorageService;
    import lombok.extern.slf4j.Slf4j;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Service;
    import com.example.base.feign.AccountFeignClient;
    
    import java.math.BigDecimal;
    
    @Service
    @Slf4j
    public class StorageServiceImpl extends ServiceImpl<StorageMapper, Storage> implements StorageService {
        @Autowired
        AccountFeignClient accountFeignClient;
    
        @Override
        public void decreaseStorage(Long productId, Integer count) {
    //        int i = 1 / 0;
            getBaseMapper().decreaseStorage(productId, count);
        }
    
        @Override
        public void decreaseStorageAndMoney(Long productId, Integer count, Long userId, BigDecimal money) {
            getBaseMapper().decreaseStorage(productId, count);
            accountFeignClient.decreaseMoney(userId, money);
        }
    }

**mapper**

package com.example.storage.mapper;
    
    import com.baomidou.mybatisplus.core.mapper.BaseMapper;
    import com.example.storage.entity.Storage;
    import org.apache.ibatis.annotations.Param;
    import org.apache.ibatis.annotations.Update;
    import org.springframework.stereotype.Repository;
    
    @Repository
    public interface StorageMapper extends BaseMapper<Storage> {
        @Update("UPDATE `t_storage` SET used= used + #{count}, residue = residue - #{count} WHERE product_id = #{productId}")
        int decreaseStorage(@Param("productId") Long productId, @Param("count") Integer count);
    }

### account ###

**controller**

package com.example.account.feign;
    
    import com.example.account.service.AccountService;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.PostMapping;
    import org.springframework.web.bind.annotation.RequestParam;
    import org.springframework.web.bind.annotation.RestController;
    
    import java.math.BigDecimal;
    
    @RestController
    public class FeignController {
        @Autowired
        AccountService accountService;
    
        @PostMapping("/feign/account/decreaseMoney")
        public void decreaseMoney(@RequestParam("userId")Long userId, @RequestParam("money")BigDecimal money) {
            accountService.decreaseMoney(userId, money);
        }
    }

**service**

Service

package com.example.account.service;
    
    import com.baomidou.mybatisplus.extension.service.IService;
    import com.example.account.entity.Account;
    
    import java.math.BigDecimal;
    
    public interface AccountService extends IService<Account> {
        void decreaseMoney(Long userId, BigDecimal money);
    }

ServiceImpl

package com.example.account.service.impl;
    
    import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
    import com.example.account.entity.Account;
    import com.example.account.mapper.AccountMapper;
    import com.example.account.service.AccountService;
    import lombok.extern.slf4j.Slf4j;
    import org.springframework.stereotype.Service;
    import org.springframework.transaction.annotation.Transactional;
    
    import java.math.BigDecimal;
    
    @Service
    @Slf4j
    public class AccountServiceImpl extends ServiceImpl<AccountMapper, Account> implements AccountService {
        @Override
        public void decreaseMoney(Long userId, BigDecimal money) {
            getBaseMapper().decreaseMoney(userId, money);
        }
    }

**mapper**

package com.example.account.mapper;
    
    import com.baomidou.mybatisplus.core.mapper.BaseMapper;
    import com.example.account.entity.Account;
    import org.apache.ibatis.annotations.Param;
    import org.apache.ibatis.annotations.Update;
    import org.springframework.stereotype.Repository;
    import org.springframework.web.bind.annotation.RequestParam;
    
    import java.math.BigDecimal;
    
    @Repository
    public interface AccountMapper extends BaseMapper<Account> {
        @Update("UPDATE `t_account` SET residue = residue - #{money},used = used + #{money} where user_id = #{userId}")
        int decreaseMoney(@Param("userId")Long userId, @Param("money") BigDecimal money);
    }

## 业务次要代码 ##

### **base** ###

**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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
        <modelVersion>4.0.0</modelVersion>
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            
            <version>2.3.7.RELEASE</version>
        </parent>
        <packaging>pom</packaging>
        <groupId>com.example</groupId>
        <artifactId>base</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <name>base</name>
        <description>Demo project for Spring Boot</description>
    
        <properties>
            <java.version>1.8</java.version>
        </properties>
    
        <dependencies>
            <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.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
            </dependency>
    
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-openfeign</artifactId>
            </dependency>
    
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <version>1.18.12</version>
                <scope>provided</scope>
            </dependency>
    
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                
            </dependency>
    
            <dependency>
                <groupId>com.baomidou</groupId>
                <artifactId>mybatis-plus-boot-starter</artifactId>
                <version>3.4.1</version>
            </dependency>
    
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-starter-alibaba-seata</artifactId>
                <version>2.2.3.RELEASE</version>
                <exclusions>
                    <exclusion>
                        <artifactId>seata-spring-boot-starter</artifactId>
                        <groupId>io.seata</groupId>
                    </exclusion>
                </exclusions>
            </dependency>
    
            <dependency>
                <groupId>io.seata</groupId>
                <artifactId>seata-spring-boot-starter</artifactId>
                <version>1.4.1</version>
            </dependency>
        </dependencies>
    
        <dependencyManagement>
            <dependencies>
                <dependency>
                    <groupId>org.springframework.cloud</groupId>
                    <artifactId>spring-cloud-dependencies</artifactId>
                    
                    <version>Hoxton.SR9</version>
                    <type>pom</type>
                    <scope>import</scope>
                </dependency>
            </dependencies>
        </dependencyManagement>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                </plugin>
                <plugin>
                    <groupId>org.codehaus.mojo</groupId>
                    <artifactId>build-helper-maven-plugin</artifactId>
                    <version>1.8</version>
                    <executions>
                        <execution>
                            <id>add-source</id>
                            <phase>generate-sources</phase>
                            <goals>
                                <goal>add-source</goal>
                            </goals>
                            <configuration>
                                <sources>
                                    <source>src/main/java</source>
                                    <source>../base</source>
                                    
                                </sources>
                            </configuration>
                        </execution>
                    </executions>
                </plugin>
            </plugins>
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
        </build>
    
    </project>

#### **配置类** ####

**通用应用注解**

package com.example.base.config;
    
    import org.mybatis.spring.annotation.MapperScan;
    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;
    import org.springframework.core.annotation.AliasFor;
    
    import java.lang.annotation.*;
    
    @Inherited
    @Target(ElementType.TYPE)
    @Retention(RetentionPolicy.RUNTIME)
    @MapperScan("com.example.**.mapper")
    @SpringBootApplication
    @EnableDiscoveryClient
    @EnableFeignClients("com.example.base.feign")
    public @interface BaseApplication {
        @AliasFor(annotation = SpringBootApplication.class)
        String[] scanBasePackages() default "com.example.**";
    
    //    @AliasFor(annotation = SpringBootApplication.class)
    //    Class<?>[] exclude() default {DataSourceAutoConfiguration.class};
    }

**mybatis-plus 自动填充插件**

package com.example.base.config;
    
    import com.baomidou.mybatisplus.core.handlers.MetaObjectHandler;
    import org.apache.ibatis.reflection.MetaObject;
    import org.mybatis.spring.annotation.MapperScan;
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    
    import java.time.LocalDateTime;
    
    @Configuration
    //@MapperScan("com.example.**.mapper")
    public class MyBatisPlusConfig {
        private static final Logger logger = LoggerFactory.getLogger(MyBatisPlusConfig.class);
    
        //自动填充插件
        @Bean
        public MetaObjectHandler metaObjectHandler() {
            return new MybatisPlusAutoFillConfig();
        }
    
        public class MybatisPlusAutoFillConfig implements MetaObjectHandler {
            // 新增时填充
            @Override
            public void insertFill(MetaObject metaObject) {
                logger.info("插入：自动填充createTime和updateTime："+ LocalDateTime.now());
                setFieldValByName("createTime", LocalDateTime.now(), metaObject);
                setFieldValByName("updateTime", LocalDateTime.now(), metaObject);
            }
    
            // 修改时填充
            @Override
            public void updateFill(MetaObject metaObject) {
                logger.info("更新：自动填充updateTime:" + LocalDateTime.now());
                setFieldValByName("updateTime", LocalDateTime.now(), metaObject);
            }
        }
    }

**feign定义**

package com.example.base.feign;
    
    import org.springframework.cloud.openfeign.FeignClient;
    import org.springframework.web.bind.annotation.PostMapping;
    import org.springframework.web.bind.annotation.RequestParam;
    
    import java.math.BigDecimal;
    
    @FeignClient("storage")
    public interface StorageFeignClient {
        @PostMapping("/feign/storage/decreaseStorage")
        void decreaseStorage(@RequestParam("productId") Long productId, @RequestParam("count") Integer count);
    
        @PostMapping("/feign/storage/decreaseStorageAndMoney")
        void decreaseStorageAndMoney(@RequestParam("productId") Long productId, @RequestParam("count") Integer count,
                             @RequestParam("userId") Long userId, @RequestParam("money")BigDecimal money);
    }

#### eureka/gateway ####

**eureka**

启动类

package com.example.eurekaserver;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;
    
    @EnableEurekaServer
    @SpringBootApplication
    public class EurekaServerApplication {
    
        public static void main(String[] args) {
            SpringApplication.run(EurekaServerApplication.class, args);
        }
    
    }

application.yml

server:
      port: 7001
    
    spring:
      application:
        name: eureka-server
    
    eureka:
      instance:
        hostname: localhost1
      client:
        register-with-eureka: false
        fetch-registry: false
        serviceUrl:
          defaultZone: http://localhost:7001/eureka/

pom.xml

**gateway**

启动类

package com.example.demo;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
    
    @SpringBootApplication
    @EnableDiscoveryClient
    public class GatewayApplication {
    
        public static void main(String[] args) {
            SpringApplication.run(GatewayApplication.class, args);
        }
    
    }

application.yml

server:
      port: 6001
    
    spring:
      application:
        name: gateway
      cloud:
        gateway:
          discovery:
            locator:
              enabled: true
              lower-case-service-id: true
          httpclient:
            ssl:
              use-insecure-trust-manager: true
    
    eureka:
      client:
        service-url:
          defaultZone: http://localhost:7001/eureka/
    
    # 配置Gateway日志等级，输出转发细节信息
    logging:
      level:
        org.springframework.cloud.gateway: debug

pom.xml

### order/storage/account ###

说明：order/storage/account的次要代码都是一样的。只是改了唯一性的东西：spring.applicaion.name、端口号、pom.xml的artifactId以及name。

**启动类**

package com.example.order;
    
    import com.example.base.config.BaseApplication;
    import org.springframework.boot.SpringApplication;
    
    @BaseApplication
    public class OrderApplication {
    
        public static void main(String[] args) {
            SpringApplication.run(OrderApplication.class, args);
        }
    
    }

**application.yml**

server:
      port: 9011
    
    spring:
      application:
        name: order
      datasource:
        driver-class-name: com.mysql.cj.jdbc.Driver
        url: jdbc:mysql://127.0.0.1:3306/demo?useUnicode=true&characterEncoding=utf8&useSSL=false&serverTimezone=GMT%2B8
        username: root
        password: 222333
    
    eureka:
      client:
        service-Url:
          defaultZone: http://localhost:7001/eureka
    #      defaultZone: http://localhost:7001/eureka,http://localhost:7002/eureka
    
    feign:
      hystrix:
        enabled: true
    
    mybatis-plus:
      configuration:
        log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
    
    seata:
      enabled: true
      application-id: order_seata
      tx-service-group: my_tx_group
      enable-auto-data-source-proxy: true
      service:
        vgroup-mapping:
          my_tx_group: default  # key与上面的tx-service-group的值对应
      registry:
        type: eureka
        eureka:
          application: default
          service-url: http://localhost:7001/eureka
          weight: 1
    #  config:
    #    type: nacos
    #    nacos:
    #      namespace:
    #      serverAddr: 127.0.0.1:8848
    #      group: SEATA_GROUP
    #      username: "nacos"
    #      password: "nacos"

**pom.xml**

## 测试 ##

启动注册中心，启动seata服务（运行seata-server-1.4.0\\seata\\bin\\seata-server.bat），启动gateway，启动各个业务微服务。

注意：启动业务微服务之后，要等输出类似下边这种打印信息才算完全启动完毕

2021-02-18 17:58:31.948  INFO 15040 --- [eoutChecker_1_1] i.s.c.r.netty.NettyClientChannelManager  : will connect to 192.168.20.17:8091
    2021-02-18 17:58:31.949  INFO 15040 --- [eoutChecker_1_1] i.s.core.rpc.netty.NettyPoolableFactory  : NettyPool create channel to transactionRole:TMROLE,address:192.168.20.17:8091,msg:< RegisterTMRequest{applicationId='order_seata', transactionServiceGroup='my_tx_group'} >
    2021-02-18 17:58:31.954  INFO 15040 --- [eoutChecker_1_1] i.s.c.rpc.netty.TmNettyRemotingClient    : register TM success. client version:1.4.1, server version:1.4.0,channel:[id: 0x6a95bd21, L:/192.168.20.17:50145 - R:/192.168.20.17:8091]
    2021-02-18 17:58:31.954  INFO 15040 --- [eoutChecker_1_1] i.s.core.rpc.netty.NettyPoolableFactory  : register success, cost 3 ms, version:1.4.0,role:TMROLE,channel:[id: 0x6a95bd21, L:/192.168.20.17:50145 - R:/192.168.20.17:8091]

**使用seata**

访问：[http://localhost:6001/order/order/create?userId=1&productId=1&count=10&money=100][http_localhost_6001_order_order_create_userId_1_productId_1_count_10_money_100]

结果：数据库全部回滚

**不使用seata**

访问：[http://localhost:6001/order/order/createNoSeata?userId=1&productId=1&count=10&money=100][http_localhost_6001_order_order_createNoSeata_userId_1_productId_1_count_10_money_100]

结果：数据库不能全部回滚

**使用seata：feign里边再调feign**

[http://localhost:6001/order/order/create2?userId=1&productId=1&count=10&money=100][http_localhost_6001_order_order_create2_userId_1_productId_1_count_10_money_100]

结果：数据库全部回滚

[--Seata_AT_--SpringCloud--_IT_-CSDN]: https://knife.blog.csdn.net/article/details/121277118
[Link 1]: https://knife.blog.csdn.net/article/details/121277224
[Seata]: http://seata.io/zh-cn/docs/ops/deploy-guide-beginner.html
[https_github.com_seata_seata_releases]: https://github.com/seata/seata/releases
[http_localhost_6001_order_order_create_userId_1_productId_1_count_10_money_100]: http://localhost:6001/order/order/create?userId=1&productId=1&count=10&money=100
[http_localhost_6001_order_order_createNoSeata_userId_1_productId_1_count_10_money_100]: http://localhost:6001/order/order/createNoSeata?userId=1&productId=1&count=10&money=100
[http_localhost_6001_order_order_create2_userId_1_productId_1_count_10_money_100]: http://localhost:6001/order/order/create2?userId=1&productId=1&count=10&money=100