序言：
分布式事务对于现在的分布式的项目来说很常见的一个问题，此次采用的是阿里开源的seata，seata官网，
此次集成不需要其seata在客户端配置相关的file.conf 、registry.conf 配置文件。
不需要配置相关的配置文件时需要引入：seata-spring-boot-starter 的pom依赖，这个是我推荐使用的集成方式。
在此工程中实践分布式事务的流程是为：
———today服务创建订单，yesterday服务进行扣减余额，若yesterday服务扣减余额发生异常，则两个服务所执行的SQL数据进行回滚。
一、工程中的代码部分：
1、父工程的依赖：
<spring-boot.version>2.3.3.RELEASE</spring-boot.version>
<spring-cloud-alibaba.version>2.2.1.RELEASE</spring-cloud-alibaba.version>
<dubbo.version>2.7.8</dubbo.version>
<seata.version>1.4.0</seata.version><dependencyManagement><dependencies><!--spring boot--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-dependencies</artifactId><version>${spring-boot.version}</version><type>pom</type><scope>import</scope></dependency><!--spring cloud alibaba--><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-alibaba-dependencies</artifactId><version>${spring-cloud-alibaba.version}</version><type>pom</type><scope>import</scope></dependency><!--seata-分布式事务管理--><dependency><groupId>io.seata</groupId><artifactId>seata-spring-boot-starter</artifactId><version>${seata.version}</version></dependency></dependencies></dependencyManagement>2、子工程的依赖：
说明：即today服务和yesterday服务需要注册到nacos中的接口所在的工程，today和yesterday都会引入此工程
<dependency><groupId>org.apache.dubbo</groupId><artifactId>dubbo-spring-boot-starter</artifactId><version>${dubbo.version}</version></dependency><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId></dependency>3、today服务和yesterday服务的启动类：
import io.seata.spring.annotation.datasource.EnableAutoDataSourceProxy;
import org.apache.dubbo.config.spring.context.annotation.EnableDubbo;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
import org.springframework.context.annotation.ComponentScan;
//开启dubbo
@EnableDubbo
//扫描工程中所依赖的包中的bean，将注册到springioc中
@ComponentScan("com.day")
//开启分布式事务的代理，将事务交给seata
@EnableAutoDataSourceProxy
//参考了pig-cloud开源项目中的动态数据源
@SpringBootApplication(exclude = {DataSourceAutoConfiguration.class})
public class XXXXXXXApplication {public static void main(String[] args) {SpringApplication.run(DayTodayApplication.class, args);}}4、today服务和yesterday服务的配置文件：
默认的配置文件：application.properties
公共的配置参数的配置文件：application-common.properties
当前开发环境的配置文件：application-dev.properties
其seata配置信息主要参考了seata官网：http://seata.io/zh-cn/docs/user/registry/nacos.html
在这里主要写出dubbo的配置信息和seata的配置信息：
#dubbo配置
dubbo.application.name=today-provider
dubbo.config-center.timeout=500000
dubbo.registry.address=nacos://${nacos.discovery.server-addr}
dubbo.protocol.name=dubbo
dubbo.protocol.port=20886
dubbo.scan.base-packages=com.day.api.provider.today
dubbo.consumer.check=false
dubbo.application.qos-enable=false
dubbo.application.qos-accept-foreign-ip=false
#seata配置
nacos.discovery.server-addr=47.104.78.115:8848
#seata-config
seata.application-id=${spring.application.name}
seata.tx-service-group=day_today_tx_group
seata.service.vgroup-mapping.day_today_tx_group=seata-days
seata.service.grouplist.seata-days=127.0.0.1:8091
seata.registry.type=nacos
seata.registry.nacos.application=seata-server
seata.registry.nacos.server-addr=${nacos.discovery.server-addr}
seata.registry.nacos.group=SEATA_GROUP
seata.registry.nacos.username=nacos
seata.registry.nacos.password=nacos
5、today服务中调用yesterday服务的代码：
控制层：
@RestController
@Api(tags = "今天的控制层信息")
@RequestMapping("/today")
public class TodayController {private static final Logger log = LoggerFactory.getLogger(TodayController.class);@DubboReference(group = DubboNacosGroup.YESTERDAY_DUBBO_NACOS)private YesterdayProvider yesterdayProvider;@Autowiredprivate IOrderService orderService;@ApiOperation(value = "测试分布式事务")@RequestMapping(value = "testDistributedTransaction", method = RequestMethod.POST)public JsonResult testDistributedTransaction() {Order order = new Order();order.setUserId("1001");order.setAmount(300d);return JsonResult.success(orderService.saveOrder(order));}
}service层：/*** 用于测试分布式事务功能** @param order* @author wangjunming* @since 2020/11/8 14:46*/@Override@GlobalTransactional(rollbackFor = Exception.class)public boolean saveOrder(Order order) {log.info("开始创建订单");final boolean save = save(order);boolean updataAmount = false;if(save){log.info("完成创建订单");log.info("开始扣减余额");AccountApiEntity accountApiEntity = new AccountApiEntity();accountApiEntity.setUserId(order.getUserId());accountApiEntity.setAmount(order.getAmount());updataAmount = yesterdayProvider.updataAmountByUserId(accountApiEntity);log.info("完成扣减余额");}log.info("开始更新订单状态");
// int i = 12/0;boolean update = false;if(updataAmount){order.setStatus(Integer.valueOf("1"));update = update(order);log.info("完成更新订单状态");}return save && updataAmount && update;}6、yesterday服务注册到nacos服务中的接口和类：
其中使用到的model和接口都在第二步中所创建的子工程中。这个时候需要调用在yesterday服务中的用户余额服务进行扣减余额。
接口：
public interface YesterdayProvider {/*** 用于测试分布式事务** @author wangjunming* @since 2020/11/8 14:52*/boolean updataAmountByUserId(AccountApiEntity accountApiEntity);}
实现类：
import com.day.api.config.DubboNacosGroup;
import com.day.api.entitys.AccountApiEntity;
import com.day.api.provider.yesterday.YesterdayProvider;
import com.day.yesterday.persistence.entity.Account;
import com.day.yesterday.persistence.service.IAccountService;
import org.apache.dubbo.config.annotation.DubboService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;@Service
@DubboService(group = DubboNacosGroup.YESTERDAY_DUBBO_NACOS)
public class YesterdayProviderImpl implements YesterdayProvider {@Autowiredprivate IAccountService accountService;/*** 用于测试分布式事务** @param accountApiEntity 扣减金额* @author wangjunming* @since 2020/11/8 14:52*/@Overridepublic boolean updataAmountByUserId(AccountApiEntity accountApiEntity) {Account account = new Account();account.setUserId(accountApiEntity.getUserId());account.setAmount(accountApiEntity.getAmount());return accountService.updataAmountByUserId(account) != null;}}7、yesterday服务中调用用户服务进行扣减余额
/*** 用于测试分布式事务，业务为根据用户ID扣减相应的余额** @param account 扣减金额* @author wangjunming* @since 2020/11/8 14:18*/@Override@GlobalTransactional(rollbackFor = Exception.class)public Account updataAmountByUserId(Account account){final Account selOneAccount = selOne(account);if (selOneAccount == null) {log.error("余额不足！");return null;}if (account.getAmount().compareTo(selOneAccount.getAmount()) > 0) {log.error("余额不足！");return null;}final double amountPoor = selOneAccount.getAmount() - account.getAmount();selOneAccount.setAmount(amountPoor);final boolean update = accountMapper.updateById(selOneAccount) > 0;int i = 12/0;return update ? selOneAccount : null;}
--------------------------至此在代码方面的工作到此结束。
二、部署seata的server端的部分：
8、初始化seata服务端和各个服务端所需要的数据库
————获取seata服务端（server）初始化SQL语句的官网地址：https://github.com/seata/seata/blob/1.4.0/script/server/db/mysql.sql
-- 创建数据库：
CREATE DATABASE `seata`;
-- -------------------------------- 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 = InnoDBDEFAULT 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 = InnoDBDEFAULT 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 = InnoDBDEFAULT CHARSET = utf8;————创建today服务中的数据库和订单表：
# -----------创建订单表---------------------------------------------------------------
# 创建 seata_order 数据库
CREATE DATABASE `seata_order`;
# 创建订单表
SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;
-- ----------------------------
-- Table structure for t_order
-- ----------------------------
DROP TABLE IF EXISTS `t_order`;
CREATE TABLE `t_order`
(`id` int(11) NOT NULL AUTO_INCREMENT,`order_no` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,`user_id` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,`commodity_code` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,`status` int(5) NULL DEFAULT 0,`amount` double(14, 2) NULL DEFAULT 0.00,PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDBAUTO_INCREMENT = 1CHARACTER SET = utf8COLLATE = utf8_general_ciROW_FORMAT = Dynamic;————创建yesterday服务中的数据库和用户钱包表：
# --------------创建用户钱包表---------------------------------------------------------
#创建 seata_pay 数据库
CREATE DATABASE `seata_pay`;
#创建用户钱包表
SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;-- ----------------------------
-- Table structure for account
-- ----------------------------
DROP TABLE IF EXISTS `account`;
CREATE TABLE `account`
(`id` int(11) NOT NULL AUTO_INCREMENT,`user_id` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,`amount` double(14, 2) NULL DEFAULT 0.00,PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDBAUTO_INCREMENT = 3CHARACTER SET = utf8COLLATE = utf8_general_ciROW_FORMAT = Dynamic;
-- ----------------------------
-- Records of account
-- ----------------------------
#初始化数据
INSERT INTO `account`
VALUES (1, '1', 4000.00);
INSERT INTO `account`
VALUES (2, '1001', 50000.00);
SET FOREIGN_KEY_CHECKS = 1;
以及在today服务的数据库（seata_order）和yesterday服务的数据库（seata_pay）所创建的undo_log表
获取创建（client端）表的SQL语句官网地址：https://github.com/seata/seata/blob/1.4.0/script/client/at/db/mysql.sql
-- 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 = InnoDBAUTO_INCREMENT = 1DEFAULT CHARSET = utf8 COMMENT ='AT transaction mode undo table';9、配置seata的server端所需要的配置信息
下载seata的server端地址：https://github.com/seata/seata/releases/tag/v1.4.0
其配置信息参考：http://seata.io/zh-cn/docs/user/registry/nacos.html
在其解压后修改conf文件下的 file.conf 和 registry.conf
1.修改 file.conf ，其中红色部分为此次修改的内容（就是将刚刚创建好的数据库）：
## transaction log store, only used in seata-server
store {
## store mode: file、db、redis
mode = "db"
## 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 = "root"
password = "123456"
minConn = 5
maxConn = 100
globalTable = "global_table"
branchTable = "branch_table"
lockTable = "lock_table"
queryLimit = 100
maxWait = 5000
}
}
2.修改 registry.conf 文件，其中红色部分是此次所需要修改的地方，以及与项目中配置文件的对应关系，在下方也有图片标注：
registry {
# file 、nacos 、eureka、redis、zk、consul、etcd3、sofa
type = "nacos"
loadBalance = "RandomLoadBalance"
loadBalanceVirtualNodes = 10
nacos {
application = "seata-server"
serverAddr = "127.0.0.1:8848"
group = "SEATA_GROUP"
namespace = ""
cluster = "seata-days"
# 重点说明：cluster = "seata-days"
# 其项目配置文件中的 seata.service.grouplist.seata-days=127.0.0.1:8091 ，此配置信息的 seata-days ，需要对应此配置文件中 cluster = "seata-days" 中 的 "seata-days" 保持一致。
# 其项目配置文件中的 seata.service.vgroup-mapping.day_today_tx_group=seata-days ，此配置信息的 seata-days ，需要对应此配置文件中 cluster = "seata-days" 中 的 "seata-days" ，保持一致，
# 也就是 与 seata.service.grouplist.seata-days=127.0.0.1:8091 ，此配置信息的 seata-days 需要保持一致。
username = "nacos"
password = "nacos"
}
}
此配置文件与项目的配置信息对应关系：
10、启动seata服务端
注意：在启动之前必须启动成功nacos1.3.0，本地则以单机模式启动nacos
启动seata服务：seata-server.bat
在nacos(本地启动nacos命令：startup.cmd -m standalone )中注册的seata服务是：
————————至此则创建完成数据库，以及成功部署seata服务。
三、测试分布式事务是否成功
11、启动today服务和yesterday服务，并查看是否已注册
12、测试：
抛出异常：
AT事务在此得到的效果，
——————至此springboot集成dubbo2.7.8+nacos1.3.2+seata1.4.0 分布式事务解决方案，已实现效果。
docker中安装nacos1.3.1
参考：
1、https://www.cnblogs.com/binz/p/12295346.html
2、https://www.jianshu.com/p/e053f016371a
命令：
1.docker search nacos
2.docker pull nacos/nacos-server:1.3.1
3.docker run -d -p 8848:8848 -e MODE=standalone -v /usr/nacos/properties/custom.properties:/home/nacos/init.d/custom.properties -v /usr/nacos/logs:/home/nacos/logs --restart always --name nacos nacos/nacos-server:1.3.1
项目中使用的整合参考：
springboot集成dubbo2.7.8+nacos1.3.2
参考： https://blog.csdn.net/lwb314/article/details/108233863
springboot整合mybatis-plus3.3.0+mybatis-plus动态数据源+druid1.1.22
参考： https://gitee.com/log4j/pig/tree/master/pig-common/pig-common-datasource 此子工程。