Seata Saga 模式理论学习、生产级使用示例搭建及注意事项（二） | Spring Cloud58

2023-12-26 23:59
文章标签 java 学习 使用 模式 spring 搭建 注意事项 理论 示例 生产 seata saga cloud58

本文主要是介绍Seata Saga 模式理论学习、生产级使用示例搭建及注意事项（二） | Spring Cloud58，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

一、前言

通过以下系列章节：

docker-compose 实现Seata Server高可用部署 | Spring Cloud 51

Seata AT 模式理论学习、事务隔离及部分源码解析 | Spring Cloud 52

Spring Boot集成Seata利用AT模式分布式事务示例 | Spring Cloud 53

Seata XA 模式理论学习、使用及注意事项 | Spring Cloud54

Seata TCC 模式理论学习、生产级使用示例搭建及注意事项 | Spring Cloud55

Seata TCC 模式下解决幂等、悬挂、空回滚问题 | Spring Cloud56

Seata Saga 模式理论学习、生产级使用示例搭建及注意事项（一） | Spring Cloud57

我们对Seata及其AT、XA、TCC、Saga事务模式的理论、使用有了深入的了解，今天专注学习Seata的Saga事务模式代码实现；并区别与官网，我们利用openfeign进行生产级示例搭建，降低入门难度。

二、示例搭建

书接上回，本示例是一个商品下单的案例，一共有三个服务和一个公共模块：

  • order-saga：业务服务，用户下单操作将在这里完成。
  • account-saga：账户服务，可以查询/修改用户的账户信息
  • storage-saga：仓储服务，可以查询/修改商品的库存数量。
  • common-tcc：公共模块，包含：实体类、openfeign接口、统一异常处理等。

2.1 业务表结构

2.1.1 订单表

DROP TABLE IF EXISTS `t_order`;
CREATE TABLE `t_order`  (`id` bigint NOT NULL AUTO_INCREMENT,`user_id` varchar(255) CHARACTER SET utf8mb3 COLLATE utf8mb3_general_ci NULL DEFAULT NULL,`commodity_code` varchar(255) CHARACTER SET utf8mb3 COLLATE utf8mb3_general_ci NULL DEFAULT NULL,`count` int NULL DEFAULT 0,`money` decimal(10, 2) NULL DEFAULT 0.00,`business_key` varchar(255) CHARACTER SET utf8mb3 COLLATE utf8mb3_general_ci NULL DEFAULT NULL,PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 23 CHARACTER SET = utf8mb3 COLLATE = utf8mb3_general_ci ROW_FORMAT = Dynamic;

2.1.2 库存表

-- ----------------------------
-- Table structure for t_storage
-- ----------------------------
DROP TABLE IF EXISTS `t_storage`;
CREATE TABLE `t_storage`  (`id` bigint NOT NULL AUTO_INCREMENT,`commodity_code` varchar(255) CHARACTER SET utf8mb3 COLLATE utf8mb3_general_ci NULL DEFAULT NULL,`count` int NULL DEFAULT 0,`business_key` varchar(255) CHARACTER SET utf8mb3 COLLATE utf8mb3_general_ci NULL DEFAULT NULL,PRIMARY KEY (`id`) USING BTREE,UNIQUE INDEX `commodity_code`(`commodity_code` ASC) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 2 CHARACTER SET = utf8mb3 COLLATE = utf8mb3_general_ci ROW_FORMAT = Dynamic;-- ----------------------------
-- Records of t_storage
-- ----------------------------
INSERT INTO `t_storage` VALUES (1, 'iphone', 3, '');

2.1.3 账户表

-- ----------------------------
-- Table structure for t_account
-- ----------------------------
DROP TABLE IF EXISTS `t_account`;
CREATE TABLE `t_account`  (`id` bigint NOT NULL AUTO_INCREMENT,`user_id` varchar(255) CHARACTER SET utf8mb3 COLLATE utf8mb3_general_ci NULL DEFAULT NULL COMMENT '用户ID',`money` decimal(10, 2) NULL DEFAULT 0.00 COMMENT '账户余额',`business_key` varchar(255) CHARACTER SET utf8mb3 COLLATE utf8mb3_general_ci NULL DEFAULT NULL COMMENT '业务标识',PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 2 CHARACTER SET = utf8mb3 COLLATE = utf8mb3_general_ci ROW_FORMAT = Dynamic;-- ----------------------------
-- Records of t_account
-- ----------------------------
INSERT INTO `t_account` VALUES (1, 'user1', 500.00, '');

2.2 项目总体结构

在这里插入图片描述
在这里插入图片描述
在这里插入图片描述
在这里插入图片描述

2.3 common-saga 搭建

2.3.1 实体类

com/gm/seata/openfeign/entity/Account.java：

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.Data;
import java.math.BigDecimal;@Data
@TableName("t_account")
public class Account {@TableId(type = IdType.ASSIGN_ID)private long id;private String userId;private BigDecimal money;private String businessKey;
}

com/gm/seata/openfeign/entity/Order.java：

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.Data;
import java.math.BigDecimal;@Data
@TableName("t_order")
public class Order {@TableId(type = IdType.ASSIGN_ID)private long id;private String userId;private String commodityCode;private int count;private BigDecimal money;private String businessKey;
}

com/gm/seata/openfeign/entity/Storage.java：

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.Data;@Data
@TableName("t_storage")
public class Storage {@TableId(type = IdType.ASSIGN_ID)private long id;private String commodityCode;private int count;private String businessKey;
}

2.3.2 feign接口

com/gm/seata/openfeign/feign/AccountServiceApi.java：

import com.gm.seata.openfeign.util.R;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import java.math.BigDecimal;@FeignClient(value = "account-saga")
public interface AccountServiceApi {/*** 扣除账户余额** @param userId* @param money* @return*/@RequestMapping(value = "deduct", method = RequestMethod.GET)R<Boolean> deduct(@RequestParam("businessKey") String businessKey, @RequestParam("userId") String userId, @RequestParam("money") BigDecimal money);/*** 补偿扣除的账户余额** @param userId* @param money* @return*/@RequestMapping(value = "compensateDeduct", method = RequestMethod.GET)R<Boolean> compensateDeduct(@RequestParam("businessKey") String businessKey, @RequestParam("userId") String userId, @RequestParam("money") BigDecimal money);
}

com/gm/seata/openfeign/feign/StorageServiceApi.java：

import com.gm.seata.openfeign.util.R;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;@FeignClient(value = "storage-saga")
public interface StorageServiceApi {/*** 扣除库存** @param commodityCode* @param count* @return*/@RequestMapping(value = "deduct", method = RequestMethod.GET)R<Boolean> deduct(@RequestParam("businessKey") String businessKey, @RequestParam("commodityCode") String commodityCode, @RequestParam("count") Integer count);/*** 补偿扣除的库存** @param commodityCode* @param count* @return*/@RequestMapping(value = "compensateDeduct", method = RequestMethod.GET)R<Boolean> compensateDeduct(@RequestParam("businessKey") String businessKey, @RequestParam("commodityCode") String commodityCode, @RequestParam("count") Integer count);
}

2.3.3 feign 微服务调用异码处理

com/gm/seata/openfeign/handle/FeignErrorDecoder.java：

import com.alibaba.fastjson.JSONObject;
import com.gm.seata.openfeign.util.ErrorEnum;
import feign.Response;
import feign.RetryableException;
import feign.Util;
import feign.codec.ErrorDecoder;
import lombok.extern.slf4j.Slf4j;
import org.springframework.context.annotation.Configuration;
import java.nio.charset.Charset;@Slf4j
@Configuration
public class FeignErrorDecoder extends ErrorDecoder.Default {@Overridepublic Exception decode(String methodKey, Response response) {try {// 可以自定义一些逻辑String message = Util.toString(response.body().asReader(Charset.forName("utf8")));JSONObject jsonObject = JSONObject.parseObject(message);int code = jsonObject.getInteger("code");ErrorEnum errorEnum = ErrorEnum.getEnumByCode(code);// 包装成自己自定义的异常return new RuntimeException(String.valueOf(errorEnum.getCode()));} catch (Exception e) {log.error("非已知异常", e.getMessage(), e);}Exception exception = super.decode(methodKey, response);// 如果是RetryableException，则返回继续重试if (exception instanceof RetryableException) {return exception;}return new RuntimeException(String.valueOf(ErrorEnum.UNKNOWN_EXCEPTION.getCode()));}
}

2.3.4 Controller 统一异常处理

com/gm/seata/openfeign/handle/GlobalBizExceptionHandler.java：

import com.gm.seata.openfeign.util.ErrorEnum;
import com.gm.seata.openfeign.util.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.core.annotation.Order;
import org.springframework.http.HttpStatus;;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseStatus;
import org.springframework.web.bind.annotation.RestControllerAdvice;/*** 全局异常处理器*/
@Slf4j
@Order(10000)
@RestControllerAdvice
public class GlobalBizExceptionHandler {/*** 全局异常.** @param e the e* @return R*/@ExceptionHandler(Exception.class)@ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)public R handleGlobalException(Exception e) {log.error("全局异常信息 ex={}", e.getMessage(), e);R r = null;// 根据异常信息与已知异常进行匹配try {int code = Integer.parseInt(e.getLocalizedMessage());ErrorEnum errorEnum = ErrorEnum.getEnumByCode(code);if (errorEnum != null) {r = R.restResult(null, errorEnum.getCode(), errorEnum.getTitle());}} finally {if (e instanceof feign.FeignException) {ErrorEnum errorEnum = ErrorEnum.UNKNOWN_EXCEPTION;r = R.restResult(null, errorEnum.getCode(), errorEnum.getTitle());}if (r == null) {r = R.failed(e.getLocalizedMessage());}}return r;}
}

2.3.5 已知异常枚举类

com/gm/seata/openfeign/util/ErrorEnum.java：

import lombok.AllArgsConstructor;
import lombok.Getter;@Getter
@AllArgsConstructor
public enum ErrorEnum {NO_SUCH_COMMODITY(3000, "无此商品"),STORAGE_LOW_PREPARE(3001, "库存不足，预扣库存失败"),STORAGE_LOW_COMMIT(3002, "库存不足，扣库存失败"),NO_SUCH_ACCOUNT(4000, "无此账户"),ACCOUNT_LOW_PREPARE(4001, "余额不足，预扣款失败"),ACCOUNT_LOW_COMMIT(4002, "余额不足，扣款失败"),UNKNOWN_EXCEPTION(9999, "远程方法调用异常");private final Integer code;private final String title;public static ErrorEnum getEnumByCode(int code) {for (ErrorEnum error : ErrorEnum.values()) {if (error.getCode().equals(code)) {return error;}}return null;}
}

2.3.6 响应信息结构体

com/gm/seata/openfeign/util/R.java：

import lombok.*;
import lombok.experimental.Accessors;
import java.io.Serializable;/*** 响应信息主体**/
@ToString
@NoArgsConstructor
@AllArgsConstructor
@Accessors(chain = true)
public class R<T> implements Serializable {private static final long serialVersionUID = 1L;/*** 成功标记*/private static final Integer SUCCESS = 0;/*** 失败标记*/private static final Integer FAIL = 1;@Getter@Setterprivate int code;@Getter@Setterprivate String msg;@Getter@Setterprivate T data;public static <T> R<T> ok() {return restResult(null, SUCCESS, null);}public static <T> R<T> ok(T data) {return restResult(data, SUCCESS, null);}public static <T> R<T> ok(T data, String msg) {return restResult(data, SUCCESS, msg);}public static <T> R<T> failed() {return restResult(null, FAIL, null);}public static <T> R<T> failed(String msg) {return restResult(null, FAIL, msg);}public static <T> R<T> failed(T data) {return restResult(data, FAIL, null);}public static <T> R<T> failed(T data, String msg) {return restResult(data, FAIL, msg);}public static <T> R<T> restResult(T data, int code, String msg) {R<T> apiResult = new R<>();apiResult.setCode(code);apiResult.setData(data);apiResult.setMsg(msg);return apiResult;}
}

2.3.7 自动配置实现

在src/main/resources/META-INF/spring路径下新建文件org.springframework.boot.autoconfigure.AutoConfiguration.imports内容如下：

com.gm.seata.openfeign.handle.GlobalBizExceptionHandler
com.gm.seata.openfeign.handle.FeignErrorDecoder

新建文件org.springframework.cloud.openfeign.FeignClient.imports内容如下：

com.gm.seata.openfeign.feign.AccountServiceApi
com.gm.seata.openfeign.feign.OrderServiceApi
com.gm.seata.openfeign.feign.StorageServiceApi

通过上述方式实现自动配置。

2.4 account-saga 搭建

2.4.1 完整依赖

seata/openfeign-saga/account-saga/pom.xml：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><parent><artifactId>openfeign-saga</artifactId><groupId>com.gm</groupId><version>0.0.1-SNAPSHOT</version></parent><modelVersion>4.0.0</modelVersion><artifactId>account-saga</artifactId><properties><maven.compiler.source>8</maven.compiler.source><maven.compiler.target>8</maven.compiler.target><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding></properties><dependencies><dependency><groupId>com.gm</groupId><artifactId>common-saga</artifactId><version>0.0.1-SNAPSHOT</version></dependency><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-bootstrap</artifactId></dependency><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-loadbalancer</artifactId></dependency><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-openfeign</artifactId></dependency><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></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>com.mysql</groupId><artifactId>mysql-connector-j</artifactId></dependency><dependency><groupId>com.baomidou</groupId><artifactId>mybatis-plus-boot-starter</artifactId><version>3.5.3.1</version></dependency></dependencies><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin></plugins></build>
</project>

2.4.2 配置文件

src/main/resources/bootstrap.yml：

server:port: 3011spring:application:name: @artifactId@cloud:nacos:username: @nacos.username@password: @nacos.password@discovery:server-addr: ${NACOS_HOST:nacos1.kc}:${NACOS_PORT:8848}datasource:driver-class-name: com.mysql.cj.jdbc.Driverurl: jdbc:mysql://192.168.0.35:3306/seata-saga-demo?useUnicode=true&characterEncoding=UTF-8&rewriteBatchedStatements=true&allowMultiQueries=true&serverTimezone=Asia/Shanghaiusername: rootpassword: '1qaz@WSX'# mybatis-plus配置控制台打印完整带参数SQL语句
mybatis-plus:configuration:log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

2.4.3 功能搭建

2.4.3.1 启动类

com/gm/seata/openfeign/AccountTCCApplication.java：

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;@SpringBootApplication
@EnableDiscoveryClient
public class AccountTCCApplication {public static void main(String[] args) {SpringApplication.run(AccountTCCApplication.class, args);}
}
2.4.3.2 Mapper类

com/gm/seata/openfeign/mapper/AccountMapper.java：

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.gm.seata.openfeign.entity.Account;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;@Mapper
public interface AccountMapper extends BaseMapper<Account> {@Select("SELECT * FROM t_account WHERE user_id = #{userId} limit 1")Account getAccountByUserId(@Param("userId") String userId);
}
2.4.3.3 Service类

com/gm/seata/openfeign/service/AccountService.java：

import java.math.BigDecimal;public interface AccountService {/*** 扣除账户余额** @param userId* @param money* @return*/boolean deduct(String businessKey, String userId, BigDecimal money);/*** 补充扣除的账户余额** @param userId* @param money* @return*/boolean compensateDeduct(String businessKey, String userId, BigDecimal money);
}

com/gm/seata/openfeign/service/impl/AccountServiceImpl.java：

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.gm.seata.openfeign.entity.Account;
import com.gm.seata.openfeign.mapper.AccountMapper;
import com.gm.seata.openfeign.service.AccountService;
import com.gm.seata.openfeign.util.ErrorEnum;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.math.BigDecimal;@Slf4j
@Service
public class AccountServiceImpl implements AccountService {@AutowiredAccountMapper accountMapper;@Overridepublic boolean deduct(String businessKey, String userId, BigDecimal money) {Account account = accountMapper.getAccountByUserId(userId);if (account == null) {//throw new RuntimeException("账户不存在");throw new RuntimeException(String.valueOf(ErrorEnum.NO_SUCH_ACCOUNT.getCode()));}// 账户余额 与 本次消费金额进行 比较if (account.getMoney().compareTo(money) < 0) {//throw new RuntimeException("余额不足，预扣款失败");throw new RuntimeException(String.valueOf(ErrorEnum.ACCOUNT_LOW_PREPARE.getCode()));}account.setMoney(account.getMoney().subtract(money));account.setBusinessKey(businessKey);QueryWrapper query = new QueryWrapper();query.eq("user_id", userId);int i = accountMapper.update(account, query);log.info("{} 账户余额扣除 {} 元", userId, money);return i == 1;}@Overridepublic boolean compensateDeduct(String businessKey, String userId, BigDecimal money) {Account account = accountMapper.getAccountByUserId(userId);account.setMoney(account.getMoney().add(money));QueryWrapper query = new QueryWrapper();query.eq("user_id", userId);query.eq("business_key", businessKey);int i = accountMapper.update(account, query);if (i == 1) {log.info("{} 账户补偿余额 {} 元", userId, money);} else {log.info("{} 账户无需补偿", userId);}return i == 1;}
}
2.4.3.4 Controller类

com/gm/seata/openfeign/controller/AccountController.java：

import com.gm.seata.openfeign.service.AccountService;
import com.gm.seata.openfeign.util.R;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import java.math.BigDecimal;@RestController
public class AccountController {@AutowiredAccountService accountService;/*** 扣除账户余额** @param userId* @param money* @return*/@RequestMapping(value = "deduct", method = RequestMethod.GET)public R<Boolean> deduct(@RequestParam("businessKey") String businessKey, @RequestParam("userId") String userId, @RequestParam("money") BigDecimal money) {return R.ok(accountService.deduct(businessKey, userId, money));}/*** 补偿扣除的账户余额** @param userId* @param money* @return*/@RequestMapping(value = "compensateDeduct", method = RequestMethod.GET)public R<Boolean> compensateDeduct(@RequestParam("businessKey") String businessKey, @RequestParam("userId") String userId, @RequestParam("money") BigDecimal money) {return R.ok(accountService.compensateDeduct(businessKey, userId, money));}
}

对外提供两个方法，对应Saga 状态机中：ServiceTask节点AccountService-deduct远程调用和补偿节点Compensation节点AccountService-compensateDeduc远程调用，如下图：

在这里插入图片描述

2.5 storage-saga 搭建

2.5.1 完整依赖

减少重复内容，请参考 2.4.1 部分，自动修改

2.5.2 配置文件

减少重复内容，请参考 2.4.2 部分，自动修改

2.5.3 功能搭建

2.5.3.1 启动类

com/gm/seata/openfeign/StorageTCCApplication.java：

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;@SpringBootApplication
@EnableDiscoveryClient
public class StorageTCCApplication {public static void main(String[] args) {SpringApplication.run(StorageTCCApplication.class, args);}
}
2.5.3.2 Mapper类

com/gm/seata/openfeign/mapper/StorageMapper.java：

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.gm.seata.openfeign.entity.Storage;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;@Mapper
public interface StorageMapper extends BaseMapper<Storage> {@Select("SELECT * FROM t_storage WHERE commodity_code = #{commodityCode} limit 1")Storage getStorageByCommodityCode(@Param("commodityCode") String commodityCode);
}
2.5.3.3 Service类

com/gm/seata/openfeign/service/StorageService.java：

public interface StorageService {/*** 扣除库存** @param commodityCode* @param count* @return*/boolean deduct(String businessKey, String commodityCode, Integer count);/*** 补充扣除库存** @param commodityCode* @param count* @return*/boolean compensateDeduct(String businessKey, String commodityCode, Integer count);
}

com/gm/seata/openfeign/service/impl/StorageServiceImpl.java：

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.gm.seata.openfeign.entity.Storage;
import com.gm.seata.openfeign.mapper.StorageMapper;
import com.gm.seata.openfeign.service.StorageService;
import com.gm.seata.openfeign.util.ErrorEnum;
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 StorageServiceImpl implements StorageService {@AutowiredStorageMapper storageMapper;@Override@Transactional(rollbackFor = Exception.class)public boolean deduct(String businessKey, String commodityCode, Integer count) {Storage storage = storageMapper.getStorageByCommodityCode(commodityCode);if (storage == null) {//throw new RuntimeException("商品不存在");throw new RuntimeException(String.valueOf(ErrorEnum.NO_SUCH_COMMODITY.getCode()));}if (storage.getCount() < count) {//throw new RuntimeException("库存不足，预扣库存失败");throw new RuntimeException(String.valueOf(ErrorEnum.STORAGE_LOW_PREPARE.getCode()));}storage.setCount(storage.getCount() - count);storage.setBusinessKey(businessKey);QueryWrapper query = new QueryWrapper();query.eq("commodity_code", commodityCode);Integer i = storageMapper.update(storage, query);log.info("{} 商品库存扣除 {} 个", commodityCode, count);return i == 1;}@Override@Transactional(rollbackFor = Exception.class)public boolean compensateDeduct(String businessKey, String commodityCode, Integer count) {Storage storage = storageMapper.getStorageByCommodityCode(commodityCode);storage.setCount(storage.getCount() + count);QueryWrapper query = new QueryWrapper();query.eq("commodity_code", commodityCode);query.eq("business_key", businessKey);Integer i = storageMapper.update(storage, query);log.info("{} 商品补偿库存 {} 个", commodityCode, count);return i == 1;}
}
2.5.3.4 Controller类

com/gm/seata/openfeign/controller/StorageController.java：

import com.gm.seata.openfeign.service.StorageService;
import com.gm.seata.openfeign.util.R;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;@RestController
public class StorageController {@AutowiredStorageService storageService;/*** 扣除商品库存** @param commodityCode* @param count* @return*/@RequestMapping(value = "deduct", method = RequestMethod.GET)public R<Boolean> deduct(@RequestParam("businessKey") String businessKey, @RequestParam("commodityCode") String commodityCode, @RequestParam("count") Integer count) {return R.ok(storageService.deduct(businessKey, commodityCode, count));}/*** 扣除商品库存** @param commodityCode* @param count* @return*/@RequestMapping(value = "compensateDeduct", method = RequestMethod.GET)public R<Boolean> compensateDeduct(@RequestParam("businessKey") String businessKey, @RequestParam("commodityCode") String commodityCode, @RequestParam("count") Integer count) {return R.ok(storageService.compensateDeduct(businessKey, commodityCode, count));}
}

对外提供两个方法，对应Saga 状态机中：ServiceTask节点StorageService-deduct远程调用和补偿节点Compensation节点`StorageService-compensateDeduct远程调用，如下图：

在这里插入图片描述

2.6 order-saga 搭建

2.6.1 完整依赖

seata/openfeign-saga/common-saga/pom.xml：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><parent><artifactId>openfeign-saga</artifactId><groupId>com.gm</groupId><version>0.0.1-SNAPSHOT</version></parent><modelVersion>4.0.0</modelVersion><artifactId>order-saga</artifactId><properties><maven.compiler.source>8</maven.compiler.source><maven.compiler.target>8</maven.compiler.target><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding></properties><dependencies><dependency><groupId>com.gm</groupId><artifactId>common-saga</artifactId><version>0.0.1-SNAPSHOT</version></dependency><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-bootstrap</artifactId></dependency><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-loadbalancer</artifactId></dependency><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-openfeign</artifactId></dependency><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></dependency><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><!-- 注意一定要引入对版本，要引入spring-cloud版本seata，而不是springboot版本的seata--><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-seata</artifactId><!-- 排除掉springcloud默认的seata版本，以免版本不一致出现问题--><exclusions><exclusion><groupId>io.seata</groupId><artifactId>seata-spring-boot-starter</artifactId></exclusion><exclusion><groupId>io.seata</groupId><artifactId>seata-all</artifactId></exclusion></exclusions></dependency><!-- 上面排除掉了springcloud默认色seata版本，此处引入和seata-server版本对应的seata包--><dependency><groupId>io.seata</groupId><artifactId>seata-spring-boot-starter</artifactId><version>1.6.1</version></dependency><!--<dependency><groupId>io.seata</groupId><artifactId>seata-spring-boot-starter</artifactId></dependency>--><dependency><groupId>com.mysql</groupId><artifactId>mysql-connector-j</artifactId></dependency><dependency><groupId>com.baomidou</groupId><artifactId>mybatis-plus-boot-starter</artifactId><version>3.5.3.1</version></dependency><dependency><groupId>com.gm</groupId><artifactId>common-tcc</artifactId><version>0.0.1-SNAPSHOT</version><scope>compile</scope></dependency></dependencies><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin><plugin><groupId>io.fabric8</groupId><artifactId>docker-maven-plugin</artifactId></plugin></plugins><resources><resource><directory>src/main/resources</directory><filtering>true</filtering><excludes><exclude>**/*.xlsx</exclude><exclude>**/*.xls</exclude></excludes></resource><resource><directory>src/main/resources</directory><filtering>false</filtering><includes><include>**/*.xlsx</include><include>**/*.xls</include></includes></resource></resources></build>
</project>

2.6.2 配置文件

src/main/resources/bootstrap.yml：

server:port: 3012spring:application:name: @artifactId@cloud:nacos:username: @nacos.username@password: @nacos.password@discovery:server-addr: ${NACOS_HOST:nacos1.kc}:${NACOS_PORT:8848}datasource:driver-class-name: com.mysql.cj.jdbc.Driverurl: jdbc:mysql://192.168.0.35:3306/seata-saga-demo?useUnicode=true&characterEncoding=UTF-8&rewriteBatchedStatements=true&allowMultiQueries=true&serverTimezone=Asia/Shanghaiusername: rootpassword: '1qaz@WSX'
seata:# 是否开启spring-boot自动装配，seata-spring-boot-starter 专有配置，默认trueenabled: true# 是否开启数据源自动代理，seata-spring-boot-starter专有配置，默认会开启数据源自动代理，可通过该配置项关闭enable-auto-data-source-proxy: false# 配置自定义事务组名称，需与下方server.vgroupMapping配置一致，程序会通过用户配置的配置中心去寻找service.vgroupMappingtx-service-group: mygroupconfig: # 从nacos配置中心获取client端配置type: nacosnacos:server-addr: ${NACOS_HOST:nacos1.kc}:${NACOS_PORT:8848}group : DEFAULT_GROUPnamespace: a4c150aa-fd09-4595-9afe-c87084b22105dataId: seataServer.propertiesusername: @nacos.username@password: @nacos.username@registry: # 通过服务中心通过服务发现获取seata-server服务地址type: nacosnacos:# 注：客户端注册中心配置的serverAddr和namespace与Server端一致，clusterName与Server端cluster一致application: seata-server # 此处与seata-server的application一致，才能通过服务发现获取服务地址group : DEFAULT_GROUPserver-addr: ${NACOS_HOST:nacos1.kc}:${NACOS_PORT:8848}userName: @nacos.username@password: @nacos.username@namespace: a4c150aa-fd09-4595-9afe-c87084b22105service:# 应用程序（客户端）会通过用户配置的配置中心去寻找service.vgroupMapping.[事务分组配置项]vgroup-mapping:# 事务分组配置项[mygroup]对应的值为TC集群名[default]，与Seata-Server中的seata.registry.nacos.cluster配置一致mygroup : default# 全局事务开关，默认false。false为开启，true为关闭disable-global-transaction: falseclient:rm:report-success-enable: true
management:endpoints:web:exposure:include: '*'logging:level:io.seata: info# mybatis-plus配置控制台打印完整带参数SQL语句
mybatis-plus:configuration:log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

状态机文件src/main/resources/statelang/order.json：

{"nodes": [{"type": "node","size": "80*72","shape": "flow-rhombus","color": "#13C2C2","label": "AccountService-deduct-Choice","stateId": "AccountService-deduct-Choice","stateType": "Choice","x": 467.875,"y": 286.5,"id": "c11238b3","stateProps": {"Type": "Choice","Choices": [{"Expression": "[deductResult] == true","Next": "StorageService-deduct"}],"Default": "Fail"},"index": 6},{"type": "node","size": "39*39","shape": "flow-circle","color": "red","label": "BService-save-catch","stateId": "BService-save-catch","stateType": "Catch","x": 524.875,"y": 431.5,"id": "053ac3ac","index": 7},{"type": "node","size": "72*72","shape": "flow-circle","color": "#FA8C16","label": "Start","stateId": "Start","stateType": "Start","stateProps": {"StateMachine": {"Name": "order","Comment": "经典的分布式调用","Version": "0.0.1"},"Next": "AService"},"x": 467.875,"y": 53,"id": "973bd79e","index": 11},{"type": "node","size": "110*48","shape": "flow-rect","color": "#1890FF","label": "AccountService-deduct","stateId": "AccountService-deduct","stateType": "ServiceTask","stateProps": {"Type": "ServiceTask","ServiceName": "accountService","Next": "AccountService-deduct-Choice","ServiceMethod": "deduct","Input": ["$.[businessKey]","$.[userId]","$.[commodityCode]","$.[count]"],"Output": {"deductResult": "$.#root"},"Status": {"#root == true": "SU","#root == false": "FA","$Exception{java.lang.Throwable}": "UN"},"CompensateState": "AccountService-compensateDeduct","Retry": []},"x": 467.875,"y": 172,"id": "e17372e4","index": 12},{"type": "node","size": "110*48","shape": "flow-rect","color": "#1890FF","label": "StorageService-deduct","stateId": "StorageService-deduct","stateType": "ServiceTask","stateProps": {"Type": "ServiceTask","ServiceName": "storageService","ServiceMethod": "deduct","CompensateState": "StorageService- compensateDeduct","Input": ["$.[businessKey]","$.[userId]","$.[commodityCode]","$.[count]"],"Output": {"deductResult": "$.#root"},"Status": {"#root == true": "SU","#root == false": "FA","$Exception{java.lang.Throwable}": "UN"},"Next": "StorageService-deduct-Choice"},"x": 467.125,"y": 411,"id": "a6c40952","index": 13},{"type": "node","size": "110*48","shape": "flow-capsule","color": "#722ED1","label": "AccountService-compensateDeduct","stateId": "AccountService-compensateDeduct","stateType": "Compensation","stateProps": {"Type": "Compensation","ServiceName": "accountService","ServiceMethod": "compensateDeduct","Input": ["$.[businessKey]","$.[userId]","$.[commodityCode]","$.[count]"]},"x": 260.625,"y": 172.5,"id": "3b348652","index": 14},{"type": "node","size": "110*48","shape": "flow-capsule","color": "#722ED1","label": "StorageService-compensateDeduct","stateId": "StorageService-compensateDeduct","stateType": "Compensation","stateProps": {"Type": "Compensation","ServiceName": "storageService","ServiceMethod": "compensateDeduct","Input": ["$.[businessKey]","$.[userId]","$.[commodityCode]","$.[count]"]},"x": 262.125,"y": 411,"id": "13b600b1","index": 15},{"type": "node","size": "72*72","shape": "flow-circle","color": "#05A465","label": "Succeed","stateId": "Succeed","stateType": "Succeed","x": 466.625,"y": 795,"id": "690e5c5e","stateProps": {"Type": "Succeed"},"index": 16},{"type": "node","size": "110*48","shape": "flow-capsule","color": "red","label": "Compensation\nTrigger","stateId": "CompensationTrigger","stateType": "CompensationTrigger","x": 881.625,"y": 430.5,"id": "757e057f","stateProps": {"Type": "CompensationTrigger","Next": "Fail"},"index": 17},{"type": "node","size": "72*72","shape": "flow-circle","color": "red","label": "Fail","stateId": "Fail","stateType": "Fail","stateProps": {"Type": "Fail","ErrorCode": "FAILED","Message": "buy failed"},"x": 881.125,"y": 285.5,"id": "0131fc0c","index": 18},{"type": "node","size": "39*39","shape": "flow-circle","color": "red","label": "AccountService-deduct-catch","stateId": "AccountService-deduct-catch","stateType": "Catch","x": 518.125,"y": 183,"id": "0955401d"},{"type": "node","size": "80*72","shape": "flow-rhombus","color": "#13C2C2","label": "StorageService-deduct-Choice","stateId": "StorageService-deduct-Choice","stateType": "Choice","x": 466.875,"y": 545.5,"id": "27978f5d","stateProps": {"Type": "Choice","Choices": [{"Expression": "[deductResult] == true","Next": "OrderService-createOrder"}],"Default": "Fail"}},{"type": "node","size": "110*48","shape": "flow-rect","color": "#1890FF","label": "OrderService-createOrder","stateId": "OrderService-createOrder","stateType": "ServiceTask","stateProps": {"Type": "ServiceTask","ServiceName": "orderService","ServiceMethod": "createOrder","CompensateState": "OrderService- compensateOrder","Input": ["$.[businessKey]","$.[userId]","$.[commodityCode]","$.[count]"],"Output": {"createOrderResult": "$.#root"},"Status": {"#root == true": "SU","#root == false": "FA","$Exception{java.lang.Throwable}": "UN"},"Next": "Succeed"},"x": 466.625,"y": 676,"id": "9351460d"},{"type": "node","size": "110*48","shape": "flow-capsule","color": "#722ED1","label": "OrderService-compensateOrder","stateId": "OrderService-compensateOrder","stateType": "Compensation","stateProps": {"Type": "Compensation","ServiceName": "orderService","ServiceMethod": "compensateOrder","Input": ["$.[businessKey]","$.[userId]","$.[commodityCode]","$.[count]"]},"x": 261.625,"y": 675.5,"id": "b2789952"},{"type": "node","size": "39*39","shape": "flow-circle","color": "red","label": "OrderService-createOrder-catch","stateId": "OrderService-createOrder-catch","stateType": "Catch","x": 523.125,"y": 696,"id": "466cf242"}],"edges": [{"source": "973bd79e","sourceAnchor": 2,"target": "e17372e4","targetAnchor": 0,"id": "f0a9008f","index": 0},{"source": "e17372e4","sourceAnchor": 2,"target": "c11238b3","targetAnchor": 0,"id": "cd8c3104","index": 2,"label": "执行结果","shape": "flow-smooth"},{"source": "c11238b3","sourceAnchor": 2,"target": "a6c40952","targetAnchor": 0,"id": "e47e49bc","stateProps": {},"label": "执行成功","shape": "flow-smooth","index": 3},{"source": "c11238b3","sourceAnchor": 1,"target": "0131fc0c","targetAnchor": 3,"id": "e3f9e775","stateProps": {},"label": "执行失败","shape": "flow-smooth","index": 4},{"source": "053ac3ac","sourceAnchor": 1,"target": "757e057f","targetAnchor": 3,"id": "3f7fe6ad","stateProps": {"Exceptions": ["java.lang.Throwable"],"Next": "CompensationTrigger"},"label": "StorageService-deduct异常触发补偿","shape": "flow-smooth","index": 5},{"source": "e17372e4","sourceAnchor": 3,"target": "3b348652","targetAnchor": 1,"id": "52a2256e","style": {"lineDash": "4"},"index": 8,"label": "","shape": "flow-smooth"},{"source": "a6c40952","sourceAnchor": 3,"target": "13b600b1","targetAnchor": 1,"id": "474512d9","style": {"lineDash": "4"},"index": 9},{"source": "757e057f","sourceAnchor": 0,"target": "0131fc0c","targetAnchor": 2,"id": "1abf48fa","index": 10},{"source": "0955401d","sourceAnchor": 1,"target": "757e057f","targetAnchor": 1,"id": "654280aa","shape": "flow-polyline-round","stateProps": {"Exceptions": ["java.lang.Throwable"],"Next": "CompensationTrigger"},"label": "AccountService-deduct异常触发补偿"},{"source": "a6c40952","sourceAnchor": 2,"target": "27978f5d","targetAnchor": 0,"id": "f25a12eb","shape": "flow-polyline-round","label": "执行结果"},{"source": "27978f5d","sourceAnchor": 2,"target": "9351460d","targetAnchor": 0,"id": "99d78285","shape": "flow-smooth","stateProps": {},"label": "执行成功"},{"source": "9351460d","sourceAnchor": 2,"target": "690e5c5e","targetAnchor": 0,"id": "82670a92","shape": "flow-polyline-round"},{"source": "9351460d","sourceAnchor": 3,"target": "b2789952","targetAnchor": 1,"id": "5db6a545","shape": "flow-polyline-round","style": {"lineDash": "4","endArrow": false},"type": "Compensation"},{"source": "466cf242","sourceAnchor": 1,"target": "757e057f","targetAnchor": 2,"id": "a9f55df2","shape": "flow-polyline-round","stateProps": {"Exceptions": ["java.lang.Throwable"],"Next": "CompensationTrigger"},"label": "OrderService-createOrder异常触发补偿"},{"source": "27978f5d","sourceAnchor": 1,"target": "0131fc0c","targetAnchor": 1,"id": "c303cae6","shape": "flow-polyline-round","stateProps": {},"label": "执行失败"}]
}

2.6.3 功能搭建

2.6.3.1 启动类

com/gm/seata/openfeign/OrderSagaApplication.java：

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.openfeign.EnableFeignClients;@SpringBootApplication
@EnableDiscoveryClient
@EnableFeignClients("com.gm.seata.openfeign.feign")
public class OrderSagaApplication {public static void main(String[] args) {SpringApplication.run(OrderSagaApplication.class, args);}
}
2.6.3.2 状态机配置类

com/gm/seata/openfeign/config/StateMachineEngineConfig.java：

import io.seata.saga.engine.config.DbStateMachineConfig;
import io.seata.saga.engine.impl.ProcessCtrlStateMachineEngine;
import io.seata.saga.rm.StateMachineEngineHolder;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
import javax.sql.DataSource;
import java.util.concurrent.ThreadPoolExecutor;/*** @Description 状态机配置*/
@Configuration
public class StateMachineEngineConfig {@AutowiredDataSource dataSource;@Beanpublic DbStateMachineConfig dbStateMachineConfig() {DbStateMachineConfig stateMachineConfig = new DbStateMachineConfig();stateMachineConfig.setDataSource(dataSource);stateMachineConfig.setResources(new String[]{"statelang/*.json"});stateMachineConfig.setEnableAsync(true);stateMachineConfig.setThreadPoolExecutor(threadExecutor());stateMachineConfig.setApplicationId("seata-server");stateMachineConfig.setTxServiceGroup("mygroup");return stateMachineConfig;}@Beanpublic ProcessCtrlStateMachineEngine stateMachineEngine() {ProcessCtrlStateMachineEngine processCtrlStateMachineEngine = new ProcessCtrlStateMachineEngine();processCtrlStateMachineEngine.setStateMachineConfig(dbStateMachineConfig());return processCtrlStateMachineEngine;}@Beanpublic StateMachineEngineHolder stateMachineEngineHolder() {StateMachineEngineHolder engineHolder = new StateMachineEngineHolder();engineHolder.setStateMachineEngine(stateMachineEngine());return engineHolder;}@Beanpublic ThreadPoolExecutor threadExecutor() {ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();//配置核心线程数executor.setCorePoolSize(1);//配置最大线程数executor.setMaxPoolSize(20);//配置队列大小executor.setQueueCapacity(99999);//配置线程池中的线程的名称前缀executor.setThreadNamePrefix("SAGA_ASYNC_EXE_");// 设置拒绝策略：当pool已经达到max size的时候，如何处理新任务// CALLER_RUNS：不在新线程中执行任务，而是有调用者所在的线程来执行executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());//执行初始化executor.initialize();return executor.getThreadPoolExecutor();}
}
2.6.3.3 Mapper类

com/gm/seata/openfeign/mapper/OrderMapper.java：

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.gm.seata.openfeign.entity.Order;
import org.apache.ibatis.annotations.Mapper;@Mapper
public interface OrderMapper extends BaseMapper<Order> {}
2.6.3.4 Service类

com/gm/seata/openfeign/service/AccountService.java：

public interface AccountService {/*** 扣除账户余额** @param businessKey* @param userId* @param commodityCode* @param count* @return*/boolean deduct(String businessKey, String userId, String commodityCode, Integer count);/*** 补偿账户余额** @param businessKey* @param userId* @param commodityCode* @param count* @return*/boolean compensateDeduct(String businessKey, String userId, String commodityCode, Integer count);
}

com/gm/seata/openfeign/service/OrderService.java：

public interface OrderService {/*** 创建订单** @param businessKey* @param userId* @param commodityCode* @param count* @return*/boolean createOrder(String businessKey, String userId, String commodityCode, Integer count);/*** 补偿（移除）已创建订单** @param businessKey* @param userId* @param commodityCode* @param count* @return*/boolean compensateOrder(String businessKey, String userId, String commodityCode, Integer count);
}

com/gm/seata/openfeign/service/StorageService.java：

public interface StorageService {/*** 扣除库存** @param businessKey* @param userId* @param commodityCode* @param count* @return*/boolean deduct(String businessKey, String userId, String commodityCode, Integer count);/*** 补充扣除库存** @param businessKey* @param userId* @param commodityCode* @param count* @return*/boolean compensateDeduct(String businessKey, String userId, String commodityCode, Integer count);
}

com/gm/seata/openfeign/service/impl/AccountServiceImpl.java：

import com.gm.seata.openfeign.feign.AccountServiceApi;
import com.gm.seata.openfeign.service.AccountService;
import com.gm.seata.openfeign.util.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.math.BigDecimal;@Slf4j
@Service(value = "accountService")
public class AccountServiceImpl implements AccountService {@AutowiredAccountServiceApi accountServiceApi;@Overridepublic boolean deduct(String businessKey, String userId, String commodityCode, Integer count) {log.info("saga状态机调用AccountService的deduct方法，参数businessKey={},userId={},commodityCode={},count={}", businessKey, userId, commodityCode, count);try {R<Boolean> result = accountServiceApi.deduct(businessKey, userId, new BigDecimal(count * 100.0));return result.getData();} catch (Exception e) {throw new RuntimeException(e.getMessage());}}@Overridepublic boolean compensateDeduct(String businessKey, String userId, String commodityCode, Integer count) {log.info("saga状态机调用AccountService的compensateDeduct方法，参数businessKey={},userId={},commodityCode={},count={}", businessKey, userId, commodityCode, count);try {R<Boolean> result = accountServiceApi.compensateDeduct(businessKey, userId, new BigDecimal(count * 100.0));return result.getData();} catch (Exception e) {throw new RuntimeException(e.getMessage());}}
}

注意：通过@Service(value = "accountService")设置服务的beanId，定义正常业务及补偿业务发起远程服务调用

com/gm/seata/openfeign/service/impl/OrderServiceImpl.java：

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.gm.seata.openfeign.entity.Order;
import com.gm.seata.openfeign.mapper.OrderMapper;
import com.gm.seata.openfeign.service.OrderService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.math.BigDecimal;@Slf4j
@Service(value = "orderService")
public class OrderServiceImpl implements OrderService {@AutowiredOrderMapper orderMapper;@Overridepublic boolean createOrder(String businessKey, String userId, String commodityCode, Integer count) {log.info("saga状态机调用OrderService的createOrder方法，参数businessKey={},userId={},commodityCode={},count={}", businessKey, userId, commodityCode, count);Order order = new Order();order.setCount(count);order.setCommodityCode(commodityCode);order.setUserId(userId);order.setMoney(new BigDecimal(count * 100.0));int i = orderMapper.insert(order);log.info("{} 用户购买的 {} 商品共计 {} 件，订单创建成功", userId, commodityCode, count);return i == 1;}@Overridepublic boolean compensateOrder(String businessKey, String userId, String commodityCode, Integer count) {log.info("saga状态机调用OrderService的compensateOrder方法，参数businessKey={},userId={},commodityCode={},count={}", businessKey, userId, commodityCode, count);QueryWrapper query = new QueryWrapper();query.eq("commodity_code", commodityCode);query.eq("userId", commodityCode);query.eq("Money", new BigDecimal(count * 100.0));int i = orderMapper.delete(query);log.info("{} 用户购买的 {} 商品共计 {} 件，订单补充（移除）成功", userId, commodityCode, count);return i == 1;}
}

com/gm/seata/openfeign/service/impl/StorageServiceImpl.java：

import com.gm.seata.openfeign.feign.StorageServiceApi;
import com.gm.seata.openfeign.service.StorageService;
import com.gm.seata.openfeign.util.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;@Slf4j
@Service(value = "storageService")
public class StorageServiceImpl implements StorageService {@AutowiredStorageServiceApi storageServiceApi;@Overridepublic boolean deduct(String businessKey, String userId, String commodityCode, Integer count) {log.info("saga状态机调用StorageService的deduct方法，参数businessKey={},userId={},commodityCode={},count={}", businessKey, userId, commodityCode, count);try {R<Boolean> result = storageServiceApi.deduct(businessKey, commodityCode, count);return result.getData();} catch (Exception e) {throw new RuntimeException(e.getMessage());}}@Overridepublic boolean compensateDeduct(String businessKey, String userId, String commodityCode, Integer count) {log.info("saga状态机调用StorageService的compensateDeduct方法，参数businessKey={},userId={},commodityCode={},count={}", businessKey, userId, commodityCode, count);try {R<Boolean> result = storageServiceApi.compensateDeduct(businessKey, commodityCode, count);return result.getData();} catch (Exception e) {throw new RuntimeException(e.getMessage());}}
}
2.6.3.5 Controller类

com/gm/seata/openfeign/controller/OrderController.java：

import com.gm.seata.openfeign.util.ErrorEnum;
import com.gm.seata.openfeign.util.R;
import io.seata.saga.engine.StateMachineEngine;
import io.seata.saga.statelang.domain.ExecutionStatus;
import io.seata.saga.statelang.domain.StateMachineInstance;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import java.util.HashMap;
import java.util.Map;@Slf4j
@RestController
public class OrderController {@AutowiredStateMachineEngine stateMachineEngine;/*** 商品下单购买** @param userId* @param commodityCode* @param count* @return*/@RequestMapping(value = "buy", method = RequestMethod.GET)public R<String> buy(@RequestParam("userId") String userId, @RequestParam("commodityCode") String commodityCode, @RequestParam("count") Integer count) {//唯一健String businessKey = String.valueOf(System.currentTimeMillis());Map<String, Object> startParams = new HashMap<>();startParams.put("businessKey", businessKey);startParams.put("userId", userId);startParams.put("commodityCode", commodityCode);startParams.put("count", count);//同步执行StateMachineInstance inst = stateMachineEngine.startWithBusinessKey("order", null, businessKey, startParams);if (ExecutionStatus.SU.equals(inst.getStatus())) {log.info("成功,saga transaction execute Succeed. XID: {},Status: {},CompensationStatus: {}", inst.getId(), inst.getStatus(), inst.getCompensationStatus());return R.ok("下单成功");} else {log.info("成功,saga transaction execute Succeed. XID: {},Status: {},CompensationStatus: {}", inst.getId(), inst.getStatus(), inst.getCompensationStatus());try {int code = Integer.parseInt(inst.getException().getMessage());return R.restResult("下单失败", code, ErrorEnum.getEnumByCode(code).getTitle());} catch (Exception e) {return R.failed("下单失败", inst.getException().getMessage());}}}
}

注意：通过stateMachineEngine.startWithBusinessKey("order", null, businessKey, startParams);开启状态机

更多状态机API请见官网：http://seata.io/zh-cn/docs/user/saga.html

三、示例测试

3.1 正常下单

由2.1章节可知：账户余额500，库存3，每件商品单价100元。

请求地址：http://127.0.0.1:3012/buy?userId=user1&count=2&commodityCode=iphone

每请求一次，扣除余额200元，扣除库存2个，已知可正常下单1次

order-saga系统日志：

在这里插入图片描述

http请求返回：

在这里插入图片描述

数据库记录：

在这里插入图片描述
在这里插入图片描述
在这里插入图片描述

3.1 余额或库存下单失败

在这里插入图片描述

storage-saga系统日志：

在这里插入图片描述

order-saga系统日志：

在这里插入图片描述
在这里插入图片描述

全局事务回滚成功

数据库记录：

在这里插入图片描述

这篇关于Seata Saga 模式理论学习、生产级使用示例搭建及注意事项（二） | Spring Cloud58的文章就介绍到这儿，希望我们推荐的文章对编程师们有所帮助！


http://www.chinasem.cn/article/541241。

相关文章

HarmonyOS学习(七)——UI（五）常用布局总结

HarmonyOS学习(七)——UI（五）常用布局总结

自适应布局 1.1、线性布局（LinearLayout） 通过线性容器Row和Column实现线性布局。Column容器内的子组件按照垂直方向排列，Row组件中的子组件按照水平方向排列。 属性说明space通过space参数设置主轴上子组件的间距，达到各子组件在排列上的等间距效果alignItems设置子组件在交叉轴上的对齐方式，且在各类尺寸屏幕上表现一致，其中交叉轴为垂直时，取值为Vert
阅读更多...
Ilya-AI分享的他在OpenAI学习到的15个提示工程技巧

Ilya-AI分享的他在OpenAI学习到的15个提示工程技巧

Ilya（不是本人，claude AI）在社交媒体上分享了他在OpenAI学习到的15个Prompt撰写技巧。 以下是详细的内容： 提示精确化:在编写提示时,力求表达清晰准确。清楚地阐述任务需求和概念定义至关重要。例:不用"分析文本",而用"判断这段话的情感倾向:积极、消极还是中性"。 快速迭代:善于快速连续调整提示。熟练的提示工程师能够灵活地进行多轮优化。例:从"总结文章"到"用
阅读更多...
JVM 的类初始化机制

JVM 的类初始化机制

前言 当你在 Java 程序中new对象时，有没有考虑过 JVM 是如何把静态的字节码（byte code）转化为运行时对象的呢，这个问题看似简单，但清楚的同学相信也不会太多，这篇文章首先介绍 JVM 类初始化的机制，然后给出几个易出错的实例来分析，帮助大家更好理解这个知识点。 JVM 将字节码转化为运行时对象分为三个阶段，分别是：loading 、Linking、initialization
阅读更多...
Spring Security 基于表达式的权限控制

Spring Security 基于表达式的权限控制

前言 spring security 3.0已经可以使用spring el表达式来控制授权，允许在表达式中使用复杂的布尔逻辑来控制访问的权限。 常见的表达式 Spring Security可用表达式对象的基类是SecurityExpressionRoot。 表达式描述hasRole([role])用户拥有制定的角色时返回true （Spring security默认会带有ROLE_前缀）,去
阅读更多...
浅析Spring Security认证过程

浅析Spring Security认证过程

类图 为了方便理解Spring Security认证流程，特意画了如下的类图，包含相关的核心认证类 概述 核心验证器 AuthenticationManager 该对象提供了认证方法的入口，接收一个Authentiaton对象作为参数; public interface AuthenticationManager {Authentication authenticate(Authenti
阅读更多...
Spring Security--Architecture Overview

Spring Security--Architecture Overview

1 核心组件 这一节主要介绍一些在Spring Security中常见且核心的Java类，它们之间的依赖，构建起了整个框架。想要理解整个架构，最起码得对这些类眼熟。 1.1 SecurityContextHolder SecurityContextHolder用于存储安全上下文（security context）的信息。当前操作的用户是谁，该用户是否已经被认证，他拥有哪些角色权限…这些都被保
阅读更多...
Spring Security基于数据库验证流程详解

Spring Security基于数据库验证流程详解

Spring Security 校验流程图 相关解释说明（认真看哦） AbstractAuthenticationProcessingFilter 抽象类 /*** 调用 #requiresAuthentication(HttpServletRequest, HttpServletResponse) 决定是否需要进行验证操作。* 如果需要验证，则会调用 #attemptAuthentica
阅读更多...
Spring Security 从入门到进阶系列教程

Spring Security 从入门到进阶系列教程

Spring Security 入门系列 《保护 Web 应用的安全》 《Spring-Security-入门（一）：登录与退出》 《Spring-Security-入门（二）：基于数据库验证》 《Spring-Security-入门（三）：密码加密》 《Spring-Security-入门（四）：自定义-Filter》 《Spring-Security-入门（五）：在 Sprin
阅读更多...
Java架构师知识体认识

Java架构师知识体认识

源码分析 常用设计模式 Proxy代理模式Factory工厂模式Singleton单例模式Delegate委派模式Strategy策略模式Prototype原型模式Template模板模式 Spring5 beans 接口实例化代理Bean操作 Context Ioc容器设计原理及高级特性Aop设计原理Factorybean与Beanfactory Transaction 声明式事物
阅读更多...
中文分词jieba库的使用与实景应用（一）

中文分词jieba库的使用与实景应用（一）

知识星球：https://articles.zsxq.com/id_fxvgc803qmr2.html 目录 一.定义： 精确模式（默认模式）： 全模式： 搜索引擎模式： paddle 模式（基于深度学习的分词模式）： 二 自定义词典 三.文本解析   调整词出现的频率 四. 关键词提取 A. 基于TF-IDF算法的关键词提取 B. 基于TextRank算法的关键词提取
阅读更多...

Copyright China编程 23002807@qq.com

沪ICP备2023033072号-2