22.SpringCloud - Spring Cloud Alibaba 之 Seata分布式事务服务；Seata TC Server集群部署（二十二）
22.SpringCloud - Spring Cloud Alibaba 之 Seata分布式事务服务；Seata TC Server集群部署（二十二）
阅读本文前可先参考：
SpringCloud - Spring Cloud Alibaba 之 Seata分布式事务服务详解；部署（十八）_MinggeQingchun的博客-CSDN博客
SpringCloud - Spring Cloud Alibaba 之 Seata分布式事务服务；集成Nacos配置中心（十九）_MinggeQingchun的博客-CSDN博客
SpringCloud - Spring Cloud Alibaba 之 Seata分布式事务服务；AT事务模式（二十）_MinggeQingchun的博客-CSDN博客
https://blog.csdn.net/MinggeQingchun/article/details/126199942
Seata TC Server集群部署
生产环境下，我们需要部署集群 Seata TC Server，实现高可用。
集群时，多个 Seata TC Server 通过 db 数据库或者redis实现全局事务会话信息的共享
每个Seata TC Server注册自己到注册中心上，应用从注册中心获得Seata TC Server实例
Seata TC Server 集群搭建具体步骤（采用Nacos注册中心）：
1、下载并解压两份 seata-server-1.4.2.tar.gz
2、初始化 Seata TC Server 的 db 数据库，在 MySQL 中，创建 seata 数据库，并在该库下执行如下SQL脚本：
通过Seata官网下载1.4.2版本的 source
使用seata-1.4.2\script\server\db脚本（MySQL）
-- -------------------------------- 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(128),
`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;3、修改 seata/conf/file.conf 配置文件，修改使用 db 数据库，实现 Seata TC Server 的全局事务会话信息的共享；
（1）mode = "db"
（2）数据库的连接信息
driverClassName = "com.mysql.cj.jdbc.Driver"
url = "jdbc:mysql://IP:3306/seata"
user = "root"
password = "123456"
4、设置使用 Nacos 注册中心；
修改 seata/conf/registry.conf 配置文件，设置使用 Nacos 注册中心；
（1）type = "nacos"
（2）Nacos连接信息：
nacos {
application = "seata-server"
serverAddr = "127.0.0.1:8848"
group = "SEATA_GROUP"
namespace = ""
cluster = "default"
username = "nacos"
password = "nacos"
}
5、启动MySQL数据库和Nacos注册中心
6、启动两个 TC Server
执行 ./seata-server.sh -p 18091 -n 1 命令，启动第一个TC Server;
-p：Seata TC Server 监听的端口；
-n：Server node，在多个 TC Server 时，需区分各自节点，用于生成不同区间的 transactionId 事务编号，以免冲突；
执行 ./seata-server.sh -p 28091 -n 2 命令，启动第二个TC Server
注：
如果使用虚拟机，最好修改内存为256MB
7、打开Nacos注册中心控制台，可以看到有两个Seata TC Server 实例
8、应用测试
一、AT事务模式：单体应用SpringBoot多数据源分布式事务
在Spring Boot单体项目中，使用了多数据源，就要保证多个数据源的数据一致性，即产生了分布式事务的问题，采用Seata的AT事务模式来解决该分布式事务问题
以下图购物下单为例
1、创建数据库、表、插入数据等
（1）accountdb账户库、account账户表
SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;
-- ----------------------------
-- Table structure for account
-- ----------------------------
DROP TABLE IF EXISTS `account`;
CREATE TABLE `account` (
`id` int(20) NOT NULL AUTO_INCREMENT,
`user_id` int(20) NULL DEFAULT NULL,
`balance` decimal(20, 0) NULL DEFAULT NULL,
`update_time` datetime(6) NULL DEFAULT NULL,
PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 2 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;
SET FOREIGN_KEY_CHECKS = 1;（2）productdb产品库、product产品表
SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;
-- ----------------------------
-- Table structure for product
-- ----------------------------
DROP TABLE IF EXISTS `product`;
CREATE TABLE `product` (
`id` int(20) NOT NULL AUTO_INCREMENT,
`name` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
`price` decimal(10, 2) NULL DEFAULT NULL,
`stock` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
`add_time` datetime(6) NULL DEFAULT NULL,
`update_time` datetime(6) NULL DEFAULT NULL,
PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 2 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;
SET FOREIGN_KEY_CHECKS = 1;（3）orderdb订单库、orders 订单表
SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;
-- ----------------------------
-- Table structure for orders
-- ----------------------------
DROP TABLE IF EXISTS `orders`;
CREATE TABLE `orders` (
`id` int(20) NOT NULL AUTO_INCREMENT,
`user_id` int(20) NULL DEFAULT NULL,
`product_id` int(20) NULL DEFAULT NULL,
`pay_amount` decimal(20, 0) NULL DEFAULT NULL,
`add_time` datetime(6) NULL DEFAULT NULL,
`update_time` datetime(6) NULL DEFAULT NULL,
PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 6 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;
SET FOREIGN_KEY_CHECKS = 1;（4）undo_log表
Seata AT 模式
-- 注意此处0.7.0+ 增加字段 context
CREATE TABLE `undo_log` (
`id` bigint(20) NOT NULL AUTO_INCREMENT,
`branch_id` bigint(20) NOT NULL,
`xid` varchar(100) NOT NULL,
`context` varchar(128) NOT NULL,
`rollback_info` longblob NOT NULL,
`log_status` int(11) NOT NULL,
`log_created` datetime NOT NULL,
`log_modified` datetime NOT NULL,
PRIMARY KEY (`id`),
UNIQUE KEY `ux_undo_log` (`xid`,`branch_id`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;注：
每个库必须创建 undo_log 表，是 Seata AT模式必须创建的表，主要用于分支事务的回滚
2、创建 SpringBoot单体应用
1、创建一个 springboot应用，命名 springcloud-alibaba-2-seata-distributed-transaction
2、添加依赖（非Spring CLoud 微服务项目，没有Spring CLoud依赖）
主要添加 Nacos-client依赖
<!-- nacos-client -->
<dependency>
<groupId>com.alibaba.nacos</groupId>
<artifactId>nacos-client</artifactId>
<version>2.1.0</version>
</dependency><groupId>com.company</groupId>
<artifactId>springcloud-alibaba-2-seata-distributed-transaction</artifactId>
<version>1.0.0</version>
<name>springcloud-alibaba-2-seata-distributed-transaction</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<spring-boot.version>2.3.12.RELEASE</spring-boot.version>
<spring-cloud-alibaba.version>2.2.7.RELEASE</spring-cloud-alibaba.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-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</dependency>
<!-- mysql-connector-java -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<!-- <version>8.0.28</version>-->
</dependency>
<!-- mybatis-spring-boot-starter -->
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>2.1.3</version>
</dependency>
<!-- seata-spring-boot-starter -->
<dependency>
<groupId>io.seata</groupId>
<artifactId>seata-spring-boot-starter</artifactId>
<version>1.3.0</version>
</dependency>
<!-- dynamic-datasource-spring-boot-starter动态数据源 -->
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>dynamic-datasource-spring-boot-starter</artifactId>
<version>3.2.0</version>
</dependency>
<!-- nacos-client -->
<dependency>
<groupId>com.alibaba.nacos</groupId>
<artifactId>nacos-client</artifactId>
<version>2.1.0</version>
</dependency>
</dependencies>
<!-- dependencyManagement标签 通常适用于多模块环境下定义一个top module来专门管理公共依赖的情况
在子项目中不写该依赖项，那么子项目仍然会从父项目depenManagement中继承该artifactId和groupId依赖项（全部继承）
若子项目 中dependencies中的dependency声明了version，则父项目中dependencyManagement中的声明无效
Spring Cloud、Spring Cloud Alibaba 以及 Spring Boot 之间版本依赖参考官网
https://github.com/alibaba/spring-cloud-alibaba/wiki/%E7%89%88%E6%9C%AC%E8%AF%B4%E6%98%8E
-->
<dependencyManagement>
<dependencies>
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-alibaba-dependencies</artifactId>
<version>${spring-cloud-alibaba.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
<!-- spring-cloud-dependencies -->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>Hoxton.SR12</version>
<type>pom</type>
<scope>import</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-dependencies</artifactId>
<version>${spring-boot.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.8</source>
<target>1.8</target>
<encoding>UTF-8</encoding>
</configuration>
</plugin>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
<!--mybatis代码自动生成插件-->
<plugin>
<groupId>org.mybatis.generator</groupId>
<artifactId>mybatis-generator-maven-plugin</artifactId>
<version>1.4.0</version>
<configuration>
<!--配置文件的位置-->
<configurationFile>src/main/resources/generatorConfig.xml</configurationFile>
<!--生成代码过程中是否打印日志-->
<verbose>true</verbose>
<!--生成时是否覆盖java文件，xml文件总是合并-->
<overwrite>true</overwrite>
</configuration>
</plugin>
</plugins>
<resources>
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.xml</include>
</includes>
</resource>
<resource>
<directory>src/main/resources</directory>
<includes>
<include>**/*.*</include>
</includes>
</resource>
</resources>
</build>3、application.properties配置文件
#内嵌服务器端口
server.port=8081
#应用服务名称
spring.application.name=springcloud-alibaba-2-seata-distributed-transaction
# 设置默认的数据源或者数据源组，默认值即为master
spring.datasource.dynamic.primary=order-ds
# 订单order数据源配置
spring.datasource.dynamic.datasource.order-ds.url=jdbc:mysql://localhost:3306/orderdb?serverTimezone=GMT%2B8&useUnicode=true&characterEncoding=utf8&rewriteBatchedStatements=true&useSSL=false
spring.datasource.dynamic.datasource.order-ds.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.dynamic.datasource.order-ds.username=root
spring.datasource.dynamic.datasource.order-ds.password=admin123456
# 商品product数据源配置
spring.datasource.dynamic.datasource.product-ds.url=jdbc:mysql://localhost:3306/productdb?serverTimezone=GMT%2B8&useUnicode=true&characterEncoding=utf8&rewriteBatchedStatements=true&useSSL=false
spring.datasource.dynamic.datasource.product-ds.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.dynamic.datasource.product-ds.username=root
spring.datasource.dynamic.datasource.product-ds.password=admin123456
# 账户account数据源配置
spring.datasource.dynamic.datasource.account-ds.url=jdbc:mysql://localhost:3306/accountdb?serverTimezone=GMT%2B8&useUnicode=true&characterEncoding=utf8&rewriteBatchedStatements=true&useSSL=false
spring.datasource.dynamic.datasource.account-ds.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.dynamic.datasource.account-ds.username=root
spring.datasource.dynamic.datasource.account-ds.password=admin123456
# 是否启动对Seata的集成
spring.datasource.dynamic.seata=true
#-----------------------------------------------------------
##单机版 tc server 配置
## Seata应用编号，默认为 ${spring.application.name}
#seata.application-id=springboot-seata
## Seata事务组编号，用于TC集群名，一般格式为：${spring.application.name}-group
#seata.tx-service-group=springboot-seata-group
## 虚拟组和分组的映射 seata.service.vgroup-mapping.${seata.tx-service-group}=default
#seata.service.vgroup-mapping.springboot-seata-group=default
## 分组和Seata服务的映射，此处default指上面 seata.service.vgroup-mapping.springboot-seata-group 的值 default
#seata.service.grouplist.default=192.168.133.129:8091
## 存储模式 默认 file模式
#seata.config.type=file
## 默认为 file
#seata.registry.type=file
#------------------------------------------------------------
#------------------------------------------------------------
#集群版 tc server 配置
# Seata应用编号，默认为 ${spring.application.name}
seata.application-id=springboot-seata
# Seata事务组编号，用于TC集群名，一般格式为：${spring.application.name}-group
seata.tx-service-group=springboot-seata-group
# 虚拟组和分组的映射 seata.service.vgroup-mapping.${seata.tx-service-group}=default
seata.service.vgroup-mapping.springboot-seata-group=default
#------------------------------------------------------------
#设置使用注册中心
seata.registry.type=nacos
seata.registry.nacos.cluster=default
seata.registry.nacos.application=seata-server
seata.registry.nacos.group=SEATA_GROUP
seata.registry.nacos.server-addr=192.168.133.129:8848
seata.enable-auto-data-source-proxy=false
seata.client.rm.lock.retry-policy-branch-rollback-on-conflict=false4、编写相应的 controller、model、mapper、service类，这里只给出调用顺序相关的类
controller测试类
@Slf4j //lombok
@RestController
public class OrderController {
@Autowired
private OrderService orderService;
@RequestMapping("/order")
public Integer createOrder(@RequestParam("userId") Integer userId,
@RequestParam("productId") Integer productId) throws Exception {
log.info("请求下单, 用户:{}, 商品:{}", userId, productId);
return orderService.createOrder(userId, productId);
}
}order逻辑类
注：
（1）@DS注解；多数据源切换
（2）@GlobalTransactional注解；seata全局事务注解
主服务加上@GlobalTransactional注解即可，被调用服务不用加@GlobalTransactional和@Transactional
@Slf4j
@Service
public class OrderServiceImpl implements OrderService {
@Autowired
private OrdersMapper ordersMapper;
@Autowired
private AccountService accountService;
@Autowired
private ProductService productService;
@Override
/**
* MyBatis-Plus 使用 @DS注解 做多数据源切换
* 语法：@DS(value = "数据源名称")
* 1、依赖：
* <dependency>
* <groupId>com.baomidou</groupId>
* <artifactId>dynamic-datasource-spring-boot-starter</artifactId>
* <version>3.0.0</version>
* </dependency>
* 2、yml 或 properties 配置
* # 设置默认的数据源或者数据源组，默认值即为master
* spring.datasource.dynamic.primary=order-ds
*
* # 订单order数据源配置
* spring.datasource.dynamic.datasource.order-ds.url=jdbc:mysql://localhost:3306/orderdb?serverTimezone=GMT%2B8&useUnicode=true&characterEncoding=utf8&rewriteBatchedStatements=true&useSSL=false
* spring.datasource.dynamic.datasource.order-ds.driver-class-name=com.mysql.cj.jdbc.Driver
* spring.datasource.dynamic.datasource.order-ds.username=root
* spring.datasource.dynamic.datasource.order-ds.password=admin123456
*
* # 商品product数据源配置
* spring.datasource.dynamic.datasource.product-ds.url=jdbc:mysql://localhost:3306/productdb?serverTimezone=GMT%2B8&useUnicode=true&characterEncoding=utf8&rewriteBatchedStatements=true&useSSL=false
* spring.datasource.dynamic.datasource.product-ds.driver-class-name=com.mysql.cj.jdbc.Driver
* spring.datasource.dynamic.datasource.product-ds.username=root
* spring.datasource.dynamic.datasource.product-ds.password=admin123456
* 3、@DS注解到实现类或者实现类的方法上才可以
* 当注解添加到类上，意味着此类里的方法都使用此数据源；
* 当注解添加到方法上时，意味着此方法上使用的数据源优先级高于其他一切配置
* 注：
* （1）注解添加在dao.mapper上无效
* （2）注解添加到interface Service类上无效
* （3）注解添加到interface Service方法上无效
*/
@DS(value = "order-ds")
@GlobalTransactional //seata全局事务注解
public Integer createOrder(Integer userId, Integer productId) throws Exception {
Integer amount = 1; // 购买数量暂时设置为 1
log.info("当前 XID: {}", RootContext.getXID());
//1、减库存
Product product = productService.reduceStock(productId, amount);
//2、减余额
accountService.reduceBalance(userId, product.getPrice());
//3、下订单
Orders order = new Orders();
order.setUserId(userId);
order.setProductId(productId);
order.setPayAmount(product.getPrice().multiply(new BigDecimal(amount)));
order.setAddTime(new Date());
ordersMapper.insertSelective(order);
//造成异常，测试是否回滚
//int a = 10/0;
log.info("下订单: {}", order.getId());
// 返回订单编号
return order.getId();
}
}
product逻辑类product逻辑类
@Slf4j
@Service
public class ProductServiceImpl implements ProductService {
@Autowired
private ProductMapper productMapper;
@Override
@DS(value = "product-ds")
public Product reduceStock(Integer productId, Integer amount) throws Exception {
log.info("当前 XID: {}", RootContext.getXID());
// 检查库存
Product product = productMapper.selectByPrimaryKey(productId);
if (product.getStock() < amount) {
throw new Exception("库存不足");
}
// 扣减库存
int updateCount = productMapper.reduceStock(productId, amount);
// 扣除成功
if (updateCount == 0) {
throw new Exception("库存不足");
}
//造成异常，测试是否回滚
//int a = 10/0;
// 扣除成功
log.info("扣除 {} 库存成功", productId);
return product;
}
}account逻辑类
@Slf4j
@Service
public class AccountServiceImpl implements AccountService {
@Autowired
private AccountMapper accountMapper;
@Override
@DS(value = "account-ds")
public void reduceBalance(Integer userId, BigDecimal money) throws Exception {
log.info("当前 XID: {}", RootContext.getXID());
// 检查余额
Account account = accountMapper.selectAccountByUserId(userId);
if (account.getBalance().doubleValue() < money.doubleValue()) {
throw new Exception("余额不足");
}
// 扣除余额
int updateCount = accountMapper.reduceBalance(userId, money);
// 扣除成功
if (updateCount == 0) {
throw new Exception("余额不足");
}
//造成异常，测试是否回滚
//int a = 10/0;
log.info("扣除用户 {} 余额成功", userId);
}
}5、启动seata-server；浏览器输入访问 http://localhost:8081/order?userId=1&productId=1
可分别在 OrderServiceImpl、ProductServiceImpl、AccountServiceImpl 实现类中 写入如下代码进行事务回滚测试
//造成异常，测试是否回滚
int a = 10/0;二、AT事务模式：微服务SpringCloud的分布式事务
1、创建 4 个SpringBoot 模块
（1）springcloud-alibaba-2-seata-distributed-commons
<dependencies>
<!--lombok-->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.16</version>
</dependency>
<!--spring-cloud-starter-openfeign-->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-openfeign</artifactId>
<version>3.0.0</version>
</dependency>
</dependencies>@FeignClient(name = "springcloud-alibaba-2-seata-distributed-account")
public interface FeignAccountService {
/**
* 扣除余额
*
* @param userId 用户ID
* @param money 扣减金额
* @throws Exception 失败时抛出异常
*/
@PostMapping("/account/reduceBalance")
void reduceBalance(@RequestParam("userId") Integer userId, @RequestParam("money") BigDecimal money);
}
@FeignClient(name = "springcloud-alibaba-2-seata-distributed-order")
public interface FeignOrderService {
/**
* 创建订单
*
* @param userId 用户ID
* @param productId 产品ID
* @return 订单编号
* @throws Exception 创建订单失败，抛出异常
*/
Integer createOrder(Integer userId, Integer productId) throws Exception;
}
@FeignClient(name = "springcloud-alibaba-2-seata-distributed-product")
public interface FeignProductService {
/**
* 减库存
*
* @param productId 商品ID
* @param amount 扣减数量
* @throws Exception 扣减失败时抛出异常
*/
@PostMapping("/product/reduceStock")
Product reduceStock(@RequestParam("productId") Integer productId, @RequestParam("amount") Integer amount);
}（2）springcloud-alibaba-2-seata-distributed-order
注意：
1、异常需要层层往上抛，如果你在子服务将异常处理的话（比如全局异常处理GlobalExceptionHandler），seata会认为你已经手动处理了异常
2、出现事务失效的情况下，优先检查 RootContext.getXID() ，xid是否传递且一致
3、主服务加上@GlobalTransactional注解即可，被调用服务不用加@GlobalTransactional和@Transactional
4、@GlobalTransactional(rollbackFor = Exception.class)最好加上rollbackFor = Exception.class，表示遇到Exception都回滚，不然遇到有些异常（如自定义异常）则不会回滚
依赖注意如下：
（1）本身有 spring-cloud-starter-alibaba-nacos-discovery 依赖，不再需要额外添加 nacos-client 依赖
（2）spring-cloud-starter-alibaba-seata 包含 seata-spring-boot-starter 依赖，但是有些配置有问题，需要自己导入和Seata Server 版本相同的依赖
<!-- spring-cloud-starter-alibaba-seata
在 Spring Cloud 项目中，spring-cloud依赖 也会引入 seata-spring-boot-starter 依赖，在此排除
-->
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-seata</artifactId>
<exclusions>
<exclusion>
<groupId>io.seata</groupId>
<artifactId>seata-spring-boot-starter</artifactId>
</exclusion>
</exclusions>
</dependency>
<!-- seata-spring-boot-starter
注：服务端和客户端版本要一致，不然报错：
no available service 'default' found, please make sure registry config correct
-->
<dependency>
<groupId>io.seata</groupId>
<artifactId>seata-spring-boot-starter</artifactId>
<version>1.4.2</version>
</dependency><groupId>com.company</groupId>
<artifactId>springcloud-alibaba-2-seata-distributed-order</artifactId>
<version>1.0.0</version>
<name>springcloud-alibaba-2-seata-distributed-order</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<spring-boot.version>2.3.12.RELEASE</spring-boot.version>
<spring-cloud-alibaba.version>2.2.7.RELEASE</spring-cloud-alibaba.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!--spring-cloud-starter-alibaba-sentinel-->
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</dependency>
<!-- mysql-connector-java -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
<!-- mybatis-spring-boot-starter -->
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>2.1.3</version>
</dependency>
<!-- spring-cloud-starter-alibaba-seata
在 Spring Cloud 项目中，spring-cloud依赖 也会引入 seata-spring-boot-starter 依赖，在此排除
-->
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-seata</artifactId>
<exclusions>
<exclusion>
<groupId>io.seata</groupId>
<artifactId>seata-spring-boot-starter</artifactId>
</exclusion>
</exclusions>
</dependency>
<!-- seata-spring-boot-starter
注：服务端和客户端版本要一致，不然报错：
no available service 'default' found, please make sure registry config correct
-->
<dependency>
<groupId>io.seata</groupId>
<artifactId>seata-spring-boot-starter</artifactId>
<version>1.4.2</version>
</dependency>
<!--统一通用项目，model类、openfeign接口-->
<dependency>
<groupId>com.company</groupId>
<artifactId>springcloud-alibaba-2-seata-distributed-commons</artifactId>
<version>1.0.0</version>
</dependency>
</dependencies>
<!-- dependencyManagement标签 通常适用于多模块环境下定义一个top module来专门管理公共依赖的情况
在子项目中不写该依赖项，那么子项目仍然会从父项目depenManagement中继承该artifactId和groupId依赖项（全部继承）
若子项目 中dependencies中的dependency声明了version，则父项目中dependencyManagement中的声明无效
Spring Cloud、Spring Cloud Alibaba 以及 Spring Boot 之间版本依赖参考官网
https://github.com/alibaba/spring-cloud-alibaba/wiki/%E7%89%88%E6%9C%AC%E8%AF%B4%E6%98%8E
-->
<dependencyManagement>
<dependencies>
<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>
<!-- spring-cloud-dependencies -->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>Hoxton.SR12</version>
<type>pom</type>
<scope>import</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-dependencies</artifactId>
<version>${spring-boot.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.1</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
<encoding>UTF-8</encoding>
</configuration>
</plugin>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
<resources>
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.xml</include>
</includes>
</resource>
<resource>
<directory>src/main/resources</directory>
<includes>
<include>**/*.*</include>
</includes>
</resource>
</resources>
</build>@Slf4j //lombok
@RestController
public class OrderController {
@Autowired
private OrderService orderService;
@RequestMapping("/order")
public Integer createOrder(@RequestParam("userId") Integer userId,
@RequestParam("productId") Integer productId) throws Exception {
log.info("请求下单, 用户:{}, 商品:{}", userId, productId);
return orderService.createOrder(userId, productId);
}
}
@Slf4j
@Service
public class OrderServiceImpl implements OrderService {
@Autowired
private OrdersMapper ordersMapper;
@Autowired
private FeignAccountService accountService;
@Autowired
private FeignProductService productService;
@Override
//seata全局事务注解；name要唯一
@GlobalTransactional//(name = "seata-order-GlobalTransactional",rollbackFor = Exception.class)
public Integer createOrder(Integer userId, Integer productId) {
Integer amount = 1; // 购买数量暂时设置为 1
log.info("当前 XID: {}", RootContext.getXID());
//1、减库存
Product product = productService.reduceStock(productId, amount);
//2、减余额
accountService.reduceBalance(userId, product.getPrice());
//3、下订单
Orders order = new Orders();
order.setUserId(userId);
order.setProductId(productId);
order.setPayAmount(product.getPrice().multiply(new BigDecimal(amount)));
order.setAddTime(new Date());
ordersMapper.insertSelective(order);
//造成异常，测试是否回滚
int a = 10/0;
log.info("下订单: {}", order.getId());
// 返回订单编号
return order.getId();
}
}来源：https://blog.csdn.net/MinggeQingchun/article/details/126225632