分布式事务--Seata-AT--SpringCloud（starter版）

青旅半醒 2023-01-06 05:48 169阅读 0赞

原文网址：[分布式事务--Seata--AT(starter)(feign)\_IT利刃出鞘的博客-CSDN博客][--Seata--AT_starter_feign_IT_-CSDN]

# 其他网址 #

**官网**

> [Seata部署指南][Seata]

**其他**

> [分布式事务--Seata AT(非starter)(feign)\_feiying0canglang的博客-CSDN博客][--Seata AT_starter_feign_feiying0canglang_-CSDN]
> 
> [springboot+seata+mybatisplus+springcloudalibaba整合demo,动动手给个star呗][springboot_seata_mybatisplus_springcloudalibaba_demo_star]  
> [SpringCloud项目升级seata遇到的坑，并使用Docker安装新版seata服务端 | 码农家园][SpringCloud_seata_Docker_seata_ _]

# 综述 #

**说明**

> 本文测试Seata AT模式（使用新版本测试）。所有代码：[https://gitee.com/shapeless/demo\_SpringCloud/tree/seata-at-2][https_gitee.com_shapeless_demo_SpringCloud_tree_seata-at-2]
> 
> 因为在之前测试Seata AT模式时，有一些问题，所以本处尝试新版本（官方说已经解决此问题）。之前的Seata AT模式的网址：[分布式事务--Seata AT(非starter)(feign)\_IT利刃出鞘的博客-CSDN博客][--Seata AT_starter_feign_feiying0canglang_-CSDN]

**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。

**技术框架**

> **所用技术栈：**
> 
>  *  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
> 
> **所用插件**
> 
>  *  lombok

**技术细节**

> **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 #

**创建数据库**

> 创建名为seata的数据库。

**seata服务事务表**

> 这几张表用于seata-server存储事务。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',
>       `create_time` datetime(0) NULL DEFAULT NULL,
>       `update_time` datetime(0) NULL DEFAULT NULL ON UPDATE CURRENT_TIMESTAMP(0),
>       PRIMARY KEY (`id`)
>     ) ENGINE=InnoDB AUTO_INCREMENT=7 DEFAULT CHARSET=utf8;
>     
>     ALTER TABLE `t_order` ADD COLUMN `status` int(1) DEFAULT NULL COMMENT '订单状态：0：创建中；1：已完结' AFTER `money` ;
> 
> 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=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;
>     
>     # INSERT INTO `seat-account`.`account` (`id`, `user_id`, `total`, `used`, `residue`) VALUES ('1', '1', '1000', '0', '100');
>     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 AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;
>     
>     # INSERT INTO `seat-storage`.`storage` (`id`, `product_id`, `total`, `used`, `residue`) VALUES ('1', '1', '100', '0', '100');
>     INSERT INTO `demo`.`t_storage` (`id`, `product_id`, `total`, `used`, `residue`) VALUES ('1', '1', '100', '0', '100');

**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** ##

**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("account")
>     public interface AccountFeignClient {
>         @PostMapping("/feign/account/decreaseMoney")
>         void decreaseMoney(@RequestParam("userId")Long userId, @RequestParam("money") BigDecimal money);
>     }
> 
>     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);
>     }

**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>

## 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
> 
>     <?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>2.1.12.RELEASE</version>
>             <relativePath/> 
>         </parent>
>         <groupId>com.example</groupId>
>         <artifactId>eureka-server</artifactId>
>         <version>0.0.1-SNAPSHOT</version>
>         <name>eureka-server</name>
>         <description>Demo project for Spring Boot</description>
>     
>         <properties>
>             <java.version>1.8</java.version>
>         </properties>
>     
>         <dependencies>
>             <dependency>
>                 <groupId>org.springframework.cloud</groupId>
>                 <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
>             </dependency>
>         </dependencies>
>     
>         <dependencyManagement>
>             <dependencies>
>                 <dependency>
>                     <groupId>org.springframework.cloud</groupId>
>                     <artifactId>spring-cloud-dependencies</artifactId>
>     
>                     <version>Greenwich.SR6</version>
>                     <type>pom</type>
>                     <scope>import</scope>
>                 </dependency>
>             </dependencies>
>         </dependencyManagement>
>     </project>

**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
> 
>     <?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>2.1.12.RELEASE</version>
>             <relativePath/> 
>         </parent>
>         <groupId>com.example</groupId>
>         <artifactId>demo</artifactId>
>         <version>0.0.1-SNAPSHOT</version>
>         <name>gateway</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</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-gateway</artifactId>
>             </dependency>
>     
>             <dependency>
>                 <groupId>org.springframework.cloud</groupId>
>                 <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
>             </dependency>
>         </dependencies>
>     
>         <dependencyManagement>
>             <dependencies>
>                 <dependency>
>                     <groupId>org.springframework.cloud</groupId>
>                     <artifactId>spring-cloud-dependencies</artifactId>
>                     <version>Greenwich.SR6</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>
>             </plugins>
>         </build>
>     
>     </project>

## 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]

> **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]

> **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]

[--Seata--AT_starter_feign_IT_-CSDN]: https://knife.blog.csdn.net/article/details/112600939
[Seata]: http://seata.io/zh-cn/docs/ops/deploy-guide-beginner.html
[--Seata AT_starter_feign_feiying0canglang_-CSDN]: https://blog.csdn.net/feiying0canglang/article/details/111867531
[springboot_seata_mybatisplus_springcloudalibaba_demo_star]: https://gitee.com/itCjb/spring-cloud-alibaba-seata-demo
[SpringCloud_seata_Docker_seata_ _]: https://www.codenong.com/cs109182278/
[https_gitee.com_shapeless_demo_SpringCloud_tree_seata-at-2]: https://gitee.com/shapeless/demo_SpringCloud/tree/seata-at-2
[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