分布式事务（四）Seata AT模式-Spring Cloud微服务案例
订单业务案例
创建 Empty Project：seata-at
数据库初始化工具
订单案例涉及四个数据库：
为了后续测试方便我们编写一个工具，用来重置所有数据库表，可以方便地把数据重置到初始状态。
新建Module：db-init
新建 Module，选择 Spring Initializr
填写 Group 和 Artifact，其他选项默认即可：
添加 JDBC 和 MySQL Driver 依赖：
完成后，pom.xml 文件如下：
<?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>2.3.3.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>cn.tedu</groupId>
<artifactId>db-init</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>db-init</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-jdbc</artifactId>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</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>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
application.yml 配置
项目的 application.properties 文件改名成 application.yml，然后添加 mysql 连接配置：
spring:
datasource:
driver-class-name: com.mysql.cj.jdbc.Driver
url: jdbc:mysql://localhost/?useUnicode=true&characterEncoding=UTF-8&serverTimezone=GMT%2B8
username: root
password: 1234
注意： 在连接地址中没有指定库名，是因为我们要先后连接四个数据库，后面执行的 sql 脚本文件中会执行 use 来进行数据库切换。
添加 sql 脚本文件
案例中的 sql 脚本来自不同的项目：
-
seata 库
seata 库是Seata Server（TC，全局事务协调器）使用的数据库，建表语句来自这里：https://github.com/seata/seata/tree/develop/script/server/db -
order、storage和account库中的
undo_log表undo_log表是各分支事务用来记录回滚日志的表，建表语句来自这里：https://github.com/seata/seata/tree/develop/script/client/at/db -
order、storage和account表
这个案例项目是 Seata 官方案例，对其做了一些改动。案例用的建表语句来自这里：https://github.com/seata/seata-samples/tree/master/springcloud-eureka-feign-mybatis-seata，在各项目的 resources 目录中的 sql 文件。 -
order库中的
segment表
EasyIdGenerator 是一个非常简单易用的全局唯一id发号器，他支持数据库自增id方式和雪花算法，由于雪花算法需要用到zookeeper服务器，为了简便起见，我们使用数据库自增id的方式。segment表就来自这个开源项目，项目地址：https://github.com/lookingatstarts/easyIdGenerator
下面，在 resources 目录下，先新建一个 sql 文件夹，四个 sql 脚本文件放在 sql 文件夹下：
seata-server.sql
drop database if exists `seata`;
CREATE DATABASE `seata` CHARSET utf8;
use `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 = 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;
order.sql
drop database if exists `seata_order`;
CREATE DATABASE `seata_order` charset utf8;
use `seata_order`;
CREATE TABLE `order` (
`id` bigint(11) NOT NULL,
`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',
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=7 DEFAULT CHARSET=utf8;
ALTER TABLE `order` ADD COLUMN `status` int(1) DEFAULT NULL COMMENT '订单状态：0：创建中；1：已完结' AFTER `money` ;
-- 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';
CREATE TABLE IF NOT EXISTS segment
(
id BIGINT UNSIGNED AUTO_INCREMENT PRIMARY KEY COMMENT '自增主键',
VERSION BIGINT DEFAULT 0 NOT NULL COMMENT '版本号',
business_type VARCHAR(63) DEFAULT '' NOT NULL COMMENT '业务类型，唯一',
max_id BIGINT DEFAULT 0 NOT NULL COMMENT '当前最大id',
step INT DEFAULT 0 NULL COMMENT '步长',
increment INT DEFAULT 1 NOT NULL COMMENT '每次id增量',
remainder INT DEFAULT 0 NOT NULL COMMENT '余数',
created_at BIGINT UNSIGNED NOT NULL COMMENT '创建时间',
updated_at BIGINT UNSIGNED NOT NULL COMMENT '更新时间',
CONSTRAINT uniq_business_type UNIQUE (business_type)
) CHARSET = utf8mb4
ENGINE INNODB COMMENT '号段表';
INSERT INTO segment
(VERSION, business_type, max_id, step, increment, remainder, created_at, updated_at)
VALUES (1, 'order_business', 1000, 1000, 1, 0, NOW(), NOW());
storage.sql
drop database if exists `seata_storage`;
CREATE DATABASE `seata_storage` charset utf8;
use `seata_storage`;
CREATE TABLE `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',
`frozen` int(11) DEFAULT '0' COMMENT 'TCC事务锁定的库存',
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;
INSERT INTO `seata_storage`.`storage` (`id`, `product_id`, `total`, `used`, `residue`) VALUES ('1', '1', '100', '0', '100');
-- 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';
account.sql
drop database if exists `seata_account`;
CREATE DATABASE `seata_account` charset utf8;
use `seata_account`;
CREATE TABLE `account` (
`id` bigint(11) NOT NULL AUTO_INCREMENT COMMENT 'id',
`user_id` bigint(11) UNIQUE 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',
`frozen` decimal(10,0) DEFAULT '0' COMMENT 'TCC事务锁定的金额',
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;
INSERT INTO `seata_account`.`account` (`id`, `user_id`, `total`, `used`, `residue`) VALUES ('1', '1', '1000', '0', '1000');
-- 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';
主程序中添加代码，执行sql脚本
Spring 中提供了一个 jdbc 脚本执行器，使用这个工具可以非常方便的运行一个 sql 脚本文件，下面是这个方法：
ScriptUtils.executeSqlScript()
只需要传入它需要的参数即可。
下面代码运行 sql 目录中的四个脚本程序，每次运行都会删除四个数据库再重新创建，并初始化数据。
package cn.tedu.dbinit;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.support.EncodedResource;
import org.springframework.jdbc.datasource.init.ScriptUtils;
import javax.annotation.PostConstruct;
import javax.sql.DataSource;
import java.sql.SQLException;
@SpringBootApplication
public class DbInitApplication {
@Autowired
private DataSource dataSource;
public static void main(String[] args) {
SpringApplication.run(DbInitApplication.class, args);
}
@PostConstruct //spring boot 初始化完成以后，会自动运行此方法
public void init() throws SQLException {
exec("sql/account.sql");
exec("sql/order.sql");
exec("sql/seata-server.sql");
exec("sql/storage.sql");
}
private void exec(String s) throws SQLException {
ClassPathResource resource = new ClassPathResource(s, DbInitApplication.class.getClassLoader());
EncodedResource encodedResource = new EncodedResource(resource, "UTF-8");
ScriptUtils.executeSqlScript(dataSource.getConnection(),encodedResource);
}
}
eureka注册中心
新建 Module：eureka-server
新建 Module：
设置 Group 和 Artifact，其他默认：
选择 eureka server 依赖：
设置项目名 eureka-server，存放路径放在 seata-at 目录下：
application.yml 配置
spring:
application:
name: eureka-server
server:
port: 8761
eureka:
server:
enable-self-preservation: false
instance:
hostname: eureka1
client:
register-with-eureka: false
fetch-registry: false
主程序添加 @EnableEurekaServer 注解
package cn.tedu.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);
}
}
启动服务可以检查eureka是否正常
POM工程搭建
父项目
为了对 order、storage和account微服务项目依赖进行统一管理，这里创建一个 pom 类型的 maven 项目，作为父项目。
新建 Maven 项目：order-parent
新建 Module，选择 Maven 项目：
填写设置，将 order-parent 项目存放在 seata-at 项目目录下：
pom.xml依赖添加
<?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">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.3.3.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>cn.tedu</groupId>
<artifactId>order-parent</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>pom</packaging>
<name>order-parent</name>
<properties>
<mybatis-plus.version>3.3.2</mybatis-plus.version>
<druid-spring-boot-starter.version>1.1.23</druid-spring-boot-starter.version>
<seata.version>1.3.0</seata.version>
<spring-cloud-alibaba-seata.version>2.0.0.RELEASE</spring-cloud-alibaba-seata.version>
<spring-cloud.version>Hoxton.SR8</spring-cloud.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-web</artifactId>
</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>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId>
<version>${mybatis-plus.version}</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid-spring-boot-starter</artifactId>
<version>${druid-spring-boot-starter.version}</version>
</dependency>
<!-- 先排除，然后添加最新版本
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-alibaba-seata</artifactId>
<version>${spring-cloud-alibaba-seata.version}</version>
<exclusions>
<exclusion>
<artifactId>seata-all</artifactId>
<groupId>io.seata</groupId>
</exclusion>
</exclusions>
</dependency>-->
<dependency>
<groupId>io.seata</groupId>
<artifactId>seata-all</artifactId>
<version>${seata.version}</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</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>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</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>
account账户项目
在这个微服务项目中实现扣减账户金额的功能。
新建 Module：account
新建Module：
设置 Group 和 Artifact，其它选项默认：
不选择任何依赖，直接点下一步，这个项目要继承 order-parent 项目：
设置 Module 名称和存储目录：
修改 pom.xml
修改 pom.xml，设置继承父项目 order-parent：
<?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">
<parent>
<artifactId>order-parent</artifactId>
<groupId>cn.tedu</groupId>
<version>1.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<groupId>cn.tedu</groupId>
<artifactId>account</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>account</name>
<description>Demo project for Spring Boot</description>
</project>
application.yml 配置
spring:
application:
name: account
datasource:
driver-class-name: com.mysql.cj.jdbc.Driver
url: jdbc:mysql://localhost/seata_account?useUnicode=true&characterEncoding=UTF-8&serverTimezone=GMT%2B8
username: root
password: 1234
server:
port: 8081
eureka:
client:
service-url:
defaultZone: http://localhost:8761/eureka
instance:
prefer-ip-address: true
mybatis-plus:
type-aliases-package: cn.tedu.account.entity
mapper-locations:
- classpath:mapper/*Mapper.xml
configuration:
map-underscore-to-camel-case: true
logging:
level:
cn.tedu.account.mapper: DEBUG
Mapper配置
先在 resources 目录下新建文件夹 mapper，然后创建文件 AccountMapper.xml：
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="cn.tedu.account.mapper.AccountMapper" >
<resultMap id="BaseResultMap" type="cn.tedu.account.entity.Account" >
<id column="id" property="id" jdbcType="BIGINT" />
<result column="user_id" property="userId" jdbcType="BIGINT" />
<result column="total" property="total" jdbcType="DECIMAL" />
<result column="used" property="used" jdbcType="DECIMAL" />
<result column="residue" property="residue" jdbcType="DECIMAL"/>
<result column="frozen" property="frozen" jdbcType="DECIMAL"/>
</resultMap>
<update id="decrease">
UPDATE account SET residue = residue - #{money},used = used + #{money} where user_id = #{userId};
</update>
</mapper>
创建 Account 实体类
package cn.tedu.account.entity;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import java.math.BigDecimal;
@Data
@NoArgsConstructor
@AllArgsConstructor
public class Account {
private Long id;
private Long userId;
private BigDecimal total;
private BigDecimal used;
private BigDecimal residue;
private BigDecimal frozen;
}
创建 AccountMapper 类
这里继承 Mybatis-Plus 提供的通用 Mapper 父类
package cn.tedu.account.mapper;
import cn.tedu.account.entity.Account;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import java.math.BigDecimal;
public interface AccountMapper extends BaseMapper<Account> {
void decrease(Long userId, BigDecimal money);
}
添加 AccountService 接口和它的实现类
decrease() 方法实现扣减账户金额的功能
package cn.tedu.account.service;
import java.math.BigDecimal;
public interface AccountService {
void decrease(Long userId, BigDecimal money);
}
1234567
package cn.tedu.account.service;
import cn.tedu.account.mapper.AccountMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.math.BigDecimal;
@Service
public class AccountServiceImpl implements AccountService {
@Autowired
private AccountMapper accountMapper;
@Override
public void decrease(Long userId, BigDecimal money) {
accountMapper.decrease(userId,money);
}
}
添加 AccountController 类提供客户端访问接口
package cn.tedu.account.controller;
import cn.tedu.account.service.AccountService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import java.math.BigDecimal;
@RestController
@Slf4j
public class AccountController {
@Autowired
private AccountService accountService;
@GetMapping("/decrease")
public String decrease(Long userId, BigDecimal money) {
accountService.decrease(userId,money);
return "用户账户扣减金额成功";
}
}
主程序添加 Mybatis 扫描注解
添加注解 @MapperScan("cn.tedu.account.mapper") ：
package cn.tedu.account;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@MapperScan("cn.tedu.account.mapper")
@SpringBootApplication
public class AccountApplication {
public static void main(String[] args) {
SpringApplication.run(AccountApplication.class, args);
}
}
启动 account 项目进行测试
-
查看 eureka 注册信息
访问 http://localhost:8761/ 查看账户服务在 eureka 中的注册信息：
-
访问账户服务执行账户扣减金额
访问 http://localhost:8081/decrease?userId=1&money=100
- 查看控制台 Mybatis 执行的 sql 日志
- 查看数据库表，确认金额已经被减掉
storage库存项目
storage 库存微服务项目，用来实现减少库存的功能。
新建 Module：storage
新建Module：
设置 Group 和 Artifact，其它选项默认：
不选择任何依赖，直接点下一步，这个项目要继承 order-parent 项目：
设置 Module 名称和存储目录：
修改 pom.xml
修改 pom.xml，设置继承父项目 order-parent：
<?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">
<parent>
<artifactId>order-parent</artifactId>
<groupId>cn.tedu</groupId>
<version>1.0-SNAPSHOT</version>
<relativePath>../order-parent/pom.xml</relativePath>
</parent>
<modelVersion>4.0.0</modelVersion>
<groupId>cn.tedu</groupId>
<artifactId>storage</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>storage</name>
<description>Demo project for Spring Boot</description>
</project>
application.yml 配置
spring:
application:
name: storage
datasource:
driver-class-name: com.mysql.cj.jdbc.Driver
url: jdbc:mysql://localhost/seata_storage?useUnicode=true&characterEncoding=UTF-8&serverTimezone=GMT%2B8
username: root
password: 1234
server:
port: 8082
eureka:
client:
service-url:
defaultZone: http://localhost:8761/eureka
instance:
prefer-ip-address: true
mybatis-plus:
type-aliases-package: cn.tedu.storage.entity
mapper-locations:
- classpath:/mapper/*Mapper.xml
configuration:
map-underscore-to-camel-case: true
logging:
level:
cn.tedu.storage.mapper: DEBUG
Mapper文件配置
先在 resources 目录下新建文件夹 mapper，然后创建文件 StorageMapper.xml：
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="cn.tedu.storage.mapper.StorageMapper" >
<resultMap id="BaseResultMap" type="cn.tedu.storage.entity.Storage" >
<id column="id" property="id" jdbcType="BIGINT" />
<result column="product_id" property="productId" jdbcType="BIGINT" />
<result column="total" property="total" jdbcType="INTEGER" />
<result column="used" property="used" jdbcType="INTEGER" />
<result column="residue" property="residue" jdbcType="INTEGER" />
</resultMap>
<update id="decrease">
UPDATE storage SET used = used + #{count},residue = residue - #{count} WHERE product_id = #{productId}
</update>
</mapper>
创建 storage 实体类
package cn.tedu.storage.entity;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
@Data
@NoArgsConstructor
@AllArgsConstructor
public class Storage {
private Long id;
private Long productId;
private Integer total;
private Integer used;
private Integer residue;
private Integer frozen;
}
创建 StorageMapper 类
这里继承 Mybatis-Plus 提供的通用 Mapper 父类
package cn.tedu.storage.mapper;
import cn.tedu.storage.entity.Storage;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
public interface StorageMapper extends BaseMapper<Storage> {
void decrease(Long productId, Integer count);
}
添加 StorageService 接口和它的实现类
decrease() 方法实现减少商品库存功能。
package cn.tedu.storage.service;
public interface StorageService {
void decrease(Long productId, Integer count) throws Exception;
}
12345
package cn.tedu.storage.service;
import cn.tedu.storage.mapper.StorageMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
@Service
public class StorageServiceImpl implements StorageService {
@Autowired
private StorageMapper storageMapper;
@Override
public void decrease(Long productId, Integer count) throws Exception {
storageMapper.decrease(productId,count);
}
}
添加 StorageController 类
提供客户端访问接口
package cn.tedu.storage.controller;
import cn.tedu.storage.service.StorageService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class StorageController {
@Autowired
private StorageService storageService;
@GetMapping("/decrease")
public String decrease(Long productId, Integer count) throws Exception {
storageService.decrease(productId,count);
return "减少商品库存成功";
}
}
主程序添加 Mybatis 扫描注解
添加注解 @MapperScan("cn.tedu.storage.mapper") ：
package cn.tedu.storage;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@MapperScan("cn.tedu.storage.mapper")
@SpringBootApplication
public class StorageApplication {
public static void main(String[] args) {
SpringApplication.run(StorageApplication.class, args);
}
}
启动 storage 项目进行测试
-
查看 eureka 注册信息
访问 http://localhost:8761/ 查看库存服务在 eureka 中的注册信息：
-
访问库存服务，执行减少库存操作
访问 http://localhost:8082/decrease?productId=1&count=1提示减少商品库存成功
- 查看控制台 Mybatis 执行的 sql 日志
- 查看数据库表，确认金额已经被减掉
order订单项目
order 订单项目保存订单，并调用 storage 和 account 减少库存和扣减金额。
需要生成全局唯一id
新建 Module：order
新建Module：
设置 Group 和 Artifact，其它选项默认：
不选择任何依赖，直接点下一步，这个项目要继承 order-parent 项目：
设置 Module 名称和存储目录：
修改 pom.xml
修改 pom.xml，设置继承父项目 order-parent：
<?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">
<parent>
<artifactId>order-parent</artifactId>
<groupId>cn.tedu</groupId>
<version>1.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<groupId>cn.tedu</groupId>
<artifactId>order</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>order</name>
<description>Demo project for Spring Boot</description>
</project>
application.yml 配置
spring:
application:
name: order
datasource:
driver-class-name: com.mysql.cj.jdbc.Driver
url: jdbc:mysql://localhost/seata_order?useUnicode=true&characterEncoding=UTF-8&serverTimezone=GMT%2B8
username: root
password: 1234
server:
port: 8083
eureka:
client:
service-url:
defaultZone: http://localhost:8761/eureka
instance:
prefer-ip-address: true
mybatis-plus:
type-aliases-package: cn.tedu.sdorder.entity
mapper-locations:
- classpath:/mapper/*Mapper.xml
configuration:
map-underscore-to-camel-case: true
logging:
level:
cn.tedu.order.mapper: DEBUG
Mapper文件配置
先在 resources 目录下新建文件夹 mapper，然后创建文件 OrderMapper.xml：
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="cn.tedu.order.mapper.OrderMapper" >
<resultMap id="BaseResultMap" type="cn.tedu.order.entity.Order" >
<id column="id" property="id" jdbcType="BIGINT" />
<result column="user_id" property="userId" jdbcType="BIGINT" />
<result column="product_id" property="productId" jdbcType="BIGINT" />
<result column="count" property="count" jdbcType="INTEGER" />
<result column="money" property="money" jdbcType="DECIMAL" />
<result column="status" property="status" jdbcType="INTEGER" />
</resultMap>
<insert id="create">
INSERT INTO `order` (`id`,`user_id`,`product_id`,`count`,`money`,`status`)
VALUES(#{id}, #{userId}, #{productId}, #{count}, #{money},1);
</insert>
</mapper>
创建 order 实体类
package cn.tedu.order.entity;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import java.math.BigDecimal;
@Data
@NoArgsConstructor
@AllArgsConstructor
public class Order {
private Long id;
private Long userId;
private Long productId;
private Integer count;
private BigDecimal money;
private Integer status;
}
创建 OrderMapper 类
这里继承 Mybatis-Plus 提供的通用 Mapper 父类
package cn.tedu.order.mapper;
import cn.tedu.order.entity.Order;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
public interface OrderMapper extends BaseMapper<Order> {
void create(Order order);
}
添加 OrderService 接口和它的实现类
create() 方法实现保存订单的功能。
package cn.tedu.order.service;
import cn.tedu.order.entity.Order;
public interface OrderService {
void create(Order order);
}
这里添加了三个 // TODO 注释，之后通过feign以及全局的id发号器完成
package cn.tedu.order.service;
import cn.tedu.order.entity.Order;
import cn.tedu.order.mapper.OrderMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.Random;
@Service
public class OrderServiceImpl implements OrderService {
@Autowired
private OrderMapper orderMapper;
@Override
public void create(Order order) {
// TODO: 从全局唯一id发号器获得id，这里暂时随机产生一个 orderId
Long orderId = Long.valueOf(new Random().nextInt(Integer.MAX_VALUE));
order.setId(orderId);
orderMapper.create(order);
// TODO: 调用storage，修改库存
// TODO: 调用account，修改账户余额
}
}
添加 OrderController 类
package cn.tedu.order.controller;
import cn.tedu.order.entity.Order;
import cn.tedu.order.service.OrderService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
@Slf4j
public class OrderController {
@Autowired
OrderService orderService;
/*
用户用这个路径进行访问：
http://localhost:8083/create?userId=1&productId=1&count=10&money=100
*/
@GetMapping("/create")
public String create(Order order) {
log.info("创建订单");
orderService.create(order);
return "创建订单成功";
}
}
主程序添加 Mybatis 扫描注解
添加注解 @MapperScan("cn.tedu.order.mapper") ：
package cn.tedu.order;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@MapperScan("cn.tedu.order.mapper")
@SpringBootApplication
public class OrderApplication {
public static void main(String[] args) {
SpringApplication.run(OrderApplication.class, args);
}
}
启动 order 项目进行测试
-
查看 eureka 注册信息
访问 http://localhost:8761/ 查看订单服务在 eureka 中的注册信：
-
访问订单服务，执行订单保存
访问 http://localhost:8083/create?userId=1&productId=1&count=10&money=100提示创建订单成功。
- 查看控制台 Mybatis 执行的 sql 日志
- 查看数据库表，确认订单保存成功
全局唯一id发号器
分布式系统中，产生唯一流水号的服务系统俗称发号器。
有很多发号器开源项目，这里使用 EasyIdGenerator，具体项目信息请访问：https://github.com/lookingatstarts/easyIdGenerator
下载项目
访问 https://github.com/lookingatstarts/easyIdGenerator ，下载发号器项目。
然后解压到当前项目的目录中
修改目录名称为easy-id-generator
导入 Module
在Maven工具窗口中点击添加按钮，选择发号器项目的 pom.xml 文件导入该项目：
注意： 如果右侧没有Maven工具标签，请按两下shift键，然后查找 “add maven projects” 就可以找到这个工具。
添加配置
pom.xml
发号器向 eureka 进行注册，以便其它服务发现它。
在pom.xml 中添加 Spring Cloud Eureka Client 依赖：
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://maven.apache.org/POM/4.0.0"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://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>2.1.2.RELEASE</version>
<relativePath/>
</parent>
<groupId>com.easy.id</groupId>
<artifactId>easy-id-generator</artifactId>
<version>1.0-SNAPSHOT</version>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<maven.compiler.target>1.8</maven.compiler.target>
<maven.compiler.source>1.8</maven.compiler.source>
<junit.version>4.12</junit.version>
<mysql.connector.version>8.0.16</mysql.connector.version>
<com.alibaba.fastjson.version>1.2.62</com.alibaba.fastjson.version>
<lombok.version>1.18.8</lombok.version>
<curator.version>2.6.0</curator.version>
</properties>
<dependencies>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>${lombok.version}</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>com.zaxxer</groupId>
<artifactId>HikariCP</artifactId>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>${mysql.connector.version}</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>${com.alibaba.fastjson.version}</version>
</dependency>
<dependency>
<groupId>org.apache.curator</groupId>
<artifactId>curator-recipes</artifactId>
<version>${curator.version}</version>
</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>
</project>
application.yml
- 配置使用数据库来生成自增id
- 向eureka进行注册
server:
port: 9090
easy-id-generator:
snowflake:
enable: false # 表示关闭雪花算法
zk:
connection-string: 127.0.0.1:2181,127.0.0.1:2182,127.0.0.1:2183
load-worker-id-from-file-when-zk-down: true # 当zk不可访问时，从本地文件中读取之前备份的workerId
segment:
enable: true # true 表示启用 数据库算法
db-list: seata_order
fetch-segment-retry-times: 3 # 从数据库获取号段失败重试次数
spring:
application:
name: easy-id-generator
eureka:
client:
service-url:
defaultZone: http://localhost:8761/eureka
seata_order.properties 数据库配置
在 resources 目录下新建配置文件 seata_order.properties，配置 seata_order 数据库的连接信息。
jdbcUrl=jdbc:mysql://localhost:3306/seata_order?autoReconnect=true&useUnicode=true&characterEncoding=UTF-8&serverTimezone=GMT%2B8
driverClassName=com.mysql.cj.jdbc.Driver
dataSource.user=root
dataSource.password=1234
dataSource.cachePrepStmts=true
dataSource.prepStmtCacheSize=250
dataSource.prepStmtCacheSqlLimit=2048
db-init 项目的 order.sql 中已经创建了数据表，并插入了一个名为 order_business 的自增id条目。
项目的 schema.sql 中为示例数据表。
启动项目并访问测试
- 查看 eureka 中的注册信息
- 访问测试
根据 SegmentEasyIdController 类的设置，访问下面地址获取自增id：
http://localhost:9090/segment/ids/next_id?businessType=order_business
order订单添加Feign，调用库存和账户服务
- 调用发号器获得全局唯一id
- 调用库存服务减少商品库存
- 调用账户服务扣减用户金额
application.yml
ribbon 默认超时时间是1秒，为了方便分布式事务测试，把超时时长改为 10 秒：
spring:
application:
name: order
datasource:
driver-class-name: com.mysql.cj.jdbc.Driver
url: jdbc:mysql://localhost/seata_order?useUnicode=true&characterEncoding=UTF-8&serverTimezone=GMT%2B8
username: root
password: root
server:
port: 8083
eureka:
client:
service-url:
defaultZone: http://localhost:8761/eureka
instance:
prefer-ip-address: true
mybatis-plus:
type-aliases-package: cn.tedu.sdorder.entity
mapper-locations:
- classpath:/mapper/*Mapper.xml
configuration:
map-underscore-to-camel-case: true
logging:
level:
cn.tedu.order.mapper: DEBUG
ribbon:
ReadTimeout: 10000
主程序添加注解启用 Feign
添加 @EnableFeignClients 注解：
package cn.tedu.order;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.openfeign.EnableFeignClients;
@EnableFeignClients
@MapperScan("cn.tedu.order.mapper")
@SpringBootApplication
public class OrderApplication {
public static void main(String[] args) {
SpringApplication.run(OrderApplication.class, args);
}
}
添加Feign声明式客户端接口
发号器的客户端接口：
package cn.tedu.order.feign;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
@FeignClient(name = "EASY-ID-GENERATOR")
public interface EasyIdGeneratorClient {
@GetMapping("/segment/ids/next_id")
Long nextId(@RequestParam String businessType);
}
库存服务的客户端接口：
package cn.tedu.order.feign;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
@FeignClient(name = "storage")
public interface StorageClient {
@GetMapping("/decrease")
String decrease(@RequestParam Long productId, @RequestParam Integer count);
}
账户服务的客户端接口：
package cn.tedu.order.feign;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import java.math.BigDecimal;
@FeignClient(name = "account")
public interface AccountClient {
@GetMapping("/decrease")
String decrease(@RequestParam Long userId, @RequestParam BigDecimal money);
}
在业务代码中通过Feign客户端调用远程服务
package cn.tedu.order.service;
import cn.tedu.order.entity.Order;
import cn.tedu.order.feign.AccountClient;
import cn.tedu.order.feign.EasyIdGeneratorClient;
import cn.tedu.order.feign.StorageClient;
import cn.tedu.order.mapper.OrderMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.Random;
@Service
public class OrderServiceImpl implements OrderService {
@Autowired
private OrderMapper orderMapper;
@Autowired
EasyIdGeneratorClient easyIdGeneratorClient;
@Autowired
private AccountClient accountClient;
@Autowired
private StorageClient storageClient;
@Override
public void create(Order order) {
// 从全局唯一id发号器获得id
Long orderId = easyIdGeneratorClient.nextId("order_business");
order.setId(orderId);
orderMapper.create(order);
// 修改库存
storageClient.decrease(order.getProductId(), order.getCount());
// 修改账户余额
accountClient.decrease(order.getUserId(), order.getMoney());
}
}
启动项目，访问测试
访问订单项目进行测试：
http://localhost:8083/create?userId=1&productId=1&count=10&money=100
- 查看 order、storage和account的控制台查看日志
- 查看三个数据库中的数据变化