玩转 Spring Boot 应用篇（序列号生成器服务实现）
0.
0.0. 历史文章整理
玩转 Spring Boot 集成篇（MySQL、Druid、HikariCP）
玩转 Spring Boot 集成篇（MyBatis、JPA、事务支持）
玩转 Spring Boot 集成篇（Actuator、Spring Boot Admin）
玩转 Spring Boot 集成篇（@Scheduled、静态、动态定时任务）
玩转 Spring Boot 集成篇（定时任务框架Quartz）
玩转 Spring Boot 原理篇（自动装配前凑之自定义Starter）
玩转 Spring Boot 原理篇（内嵌Tomcat实现原理&优雅停机源码剖析）
玩转 Spring Boot 应用篇（解决菜菜店铺商品超卖问题）
玩转 Spring Boot 应用篇（引入Redis解决店铺高并发读的问题）
玩转 Spring Boot 应用篇（引入RabbitMQ解决店铺下单峰值问题）
0.1. 背景
在微服务盛行的当下，模块拆分粒度越来越细，若排查问题时，就需要一个能贯穿始终的全局唯一的 ID；在支付场景中的订单编号，银行流水号等生成均需要依赖序列号生成的工具。
本次基于 Spring Boot + Redis + Lua 来实现一个序列号生成器服务，并尝试包装成 Spring Boot Starter 进而彻底解决项目中序列号生成的难题。
- 技术栈：Spring Boot 2.6.3 + Redis + Lua
- 环境依赖： JDK 1.8 + Maven 3.6.3
1. 搭建序列号生成服务
- 项目结构一览
- 引入依赖
<?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>2.6.3</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>idgenerator</artifactId>
<version>0.0.1</version>
<name>idgenerator</name>
<description>Id generator for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.21.0</version>
<configuration>
<!--默认关掉单元测试 -->
<skipTests>true</skipTests>
</configuration>
</plugin>
</plugins>
</build>
</project>- 添加 Redis 相关配置
在 application.properties 文件中加入 redis 相关配置。
### Redis 缓存配置信息
# 主机名称
spring.redis.host=127.0.0.1
# 端口号
spring.redis.port=6379
# 认证密码
spring.redis.password=
# 连接超时时间
spring.redis.timeout=500
# 默认数据库
spring.redis.database=0- 编写 Lua 脚本
在 resources 目录下创建 redis-script-single.lua 文件，内容如下。
-- moudle tag
local tag = KEYS[1];
if tag == nil then
tag = 'default';
end
-- if user do not pass shardId, default partition is 0.
local partition
if KEYS[2] == nil then
partition = 0;
else
partition = KEYS[2] % 4096;
end
local seqKey = 'idgenerator_' .. tag .. '_' .. partition;
local step = 1;
local count;
repeat
count = tonumber(redis.call('INCRBY', seqKey, step));
until count < (1024 - step)
-- count how many seq are generated in one millisecond
if count == step then
redis.call('PEXPIRE', seqKey, 1);
end
local now = redis.call('TIME');
-- second, microSecond, partition, seq
return { tonumber(now[1]), tonumber(now[2]), partition, count }重点关注 redis.call('INCRBY', seqKey, step) 作用是对 seqKey 按照 step 步长进行递增；以及 redis.call('PEXPIRE', seqKey, 1); 设置 seqKey 的失效时间，可依据需求是否需要。
- Redis 脚本支持类定义（ScriptConfiguration.java）
创建 RedisScript 的子类 DefaultRedisScript 对象，内部设置了 lua 文件的位置以及脚本返回格式。
package com.example.idgenerator.config;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.Resource;
import org.springframework.data.redis.core.script.RedisScript;
import org.springframework.scripting.support.ResourceScriptSource;
import java.util.List;
@Configuration
public class ScriptConfiguration {
@Bean
public RedisScript<List> redisScript() {
Resource resource = new ResourceScriptSource(new ClassPathResource("redis-script-single.lua")).getResource();
return RedisScript.of(resource, List.class);
}
}- 定义序列号 Service（IdGenService.java）
package com.example.idgenerator.service;
/**
* 序列号生成器 Service
*/
public interface IdGenService {
String next();
}- 定义序列号 Service 实现（RedisIdGenService.java）
package com.example.idgenerator.service.impl;
import com.example.idgenerator.service.IdGenService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.RedisScript;
import org.springframework.stereotype.Service;
import java.util.ArrayList;
import java.util.List;
@Service
public class RedisIdGenService implements IdGenService {
private Logger logger = LoggerFactory.getLogger(RedisIdGenService.class);
@Autowired
private StringRedisTemplate stringRedisTemplate;
@Autowired
private RedisScript<List> redisScript;
public String next() {
List<String> keys = new ArrayList<>();
//keys.add("USER_MOUDLE");
//keys.add("1");
List<Long> result = stringRedisTemplate.execute(redisScript, keys);
long id = buildId(result.get(0), result.get(1), result.get(2), result.get(3));
logger.info("序列号：" + id);
return String.valueOf(id);
}
public long buildId(long second, long microSecond, long shardId, long seq) {
long miliSecond = second * 1000L + microSecond / 1000L;
return (miliSecond << 22) + (shardId << 10) + seq;
}
}- 定义序列号 API（IdGenController.java）
package com.example.idgenerator.controller;
import com.example.idgenerator.service.IdGenService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class IdGenController {
private Logger logger = LoggerFactory.getLogger(IdGenController.class);
@Autowired
private IdGenService idGenService;
@GetMapping("/getId")
public String getId() {
String seq = idGenService.next();
logger.info("生成序列号：" + seq);
return seq;
}
}- 启动服务验证
启动服务，浏览器访问 http://localhost:8080/getId，控制台输出：
至此，一个基于 Spring Boot 的序列号生成器服务就完成了，可以直接集成到项目中去使用，不过是提供 HTTP 的服务，若不直接提供 WEB 服务，考虑到使用方便，是否可以考虑封装成 starter 呢？
2. 包装成序列号生成器 starter
考虑到直观，直接新建项目，项目名：idgenerator-spring-boot-starter，项目整体结构如下。
- 添加依赖
<?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>2.6.3</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>org.idgenerator</groupId>
<artifactId>idgenerator-spring-boot-starter</artifactId>
<version>0.0.1</version>
<name>idgenerator-spring-boot-starter</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-configuration-processor</artifactId>
<optional>true</optional>
</dependency>
</dependencies>
</project>- 添加 Redis 相关配置
### Redis 缓存配置信息
# 主机名称
spring.redis.host=127.0.0.1
# 端口号
spring.redis.port=6379
# 认证密码
spring.redis.password=
# 连接超时时间
spring.redis.timeout=500
# 默认数据库
spring.redis.database=0- 编写 Lua 脚本
-- moudle tag
local tag = KEYS[1];
if tag == nil then
tag = 'default';
end
-- if user do not pass shardId, default partition is 0.
local partition
if KEYS[2] == nil then
partition = 0;
else
partition = KEYS[2] % 4096;
end
local seqKey = 'idgenerator_' .. tag .. '_' .. partition;
local step = 1;
local count;
repeat
count = tonumber(redis.call('INCRBY', seqKey, step));
until count < (1024 - step)
-- count how many seq are generated in one millisecond
if count == step then
redis.call('PEXPIRE', seqKey, 1);
end
local now = redis.call('TIME');
-- second, microSecond, partition, seq
return { tonumber(now[1]), tonumber(now[2]), partition, count }- 编写 Service 以及实现
package org.idgenerator.service;
/**
* 序列号生成器 Service
*/
public interface IdGenService {
String next();
}package org.idgenerator.service.impl;
import org.idgenerator.service.IdGenService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.Resource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.RedisScript;
import org.springframework.scripting.support.ResourceScriptSource;
import org.springframework.stereotype.Service;
import java.util.ArrayList;
import java.util.List;
@Service
public class RedisIdGenService implements IdGenService {
private Logger logger = LoggerFactory.getLogger(RedisIdGenService.class);
private StringRedisTemplate stringRedisTemplate;
private RedisScript<List> redisScript;
public RedisIdGenService(StringRedisTemplate stringRedisTemplate) {
this.stringRedisTemplate = stringRedisTemplate;
Resource luaResource = new ResourceScriptSource(new ClassPathResource("redis-script-single.lua")).getResource();
RedisScript<List> redisScript = RedisScript.of(luaResource,List.class);
this.redisScript = redisScript;
}
public String next() {
List<String> keys = new ArrayList<>();
//keys.add("USER_MOUDLE");
//keys.add("1");
List<Long> result = stringRedisTemplate.execute(redisScript, keys);
long id = buildId(result.get(0), result.get(1), result.get(2), result.get(3));
logger.info("序列号：" + id);
return String.valueOf(id);
}
public long buildId(long second, long microSecond, long shardId, long seq) {
long miliSecond = second * 1000L + microSecond / 1000L;
return (miliSecond << 22) + (shardId << 10) + seq;
}
}
- 定义 IdGenAutoConfiguration 自动配置类
package org.idgenerator.autoconfigure;
import org.idgenerator.service.IdGenService;
import org.idgenerator.service.impl.RedisIdGenService;
import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.core.StringRedisTemplate;
@Configuration
@ConditionalOnClass({StringRedisTemplate.class})
public class IdGenAutoConfiguration {
@Bean
@ConditionalOnMissingBean(IdGenService.class)
public IdGenService idGen(StringRedisTemplate stringRedisTemplate) {
return new RedisIdGenService(stringRedisTemplate);
}
}- 定义 spring.factories 文件
在 resources 目录下创建 META-INF 文件夹，然后创建 spring.factories 文件，文件内容如下。
org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
org.idgenerator.autoconfigure.IdGenAutoConfiguration- 编译打包
3. 序列号生成器 starter 验证
创建 ToyApp 项目，并引入第 2 步编译之后的序列号生成器 starter。
- pom.xml 详细内容。
<?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>2.6.3</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>ToyApp</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>ToyApp</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
<dependency>
<groupId>org.idgenerator</groupId>
<artifactId>idgenerator-spring-boot-starter</artifactId>
<systemPath>
${project.basedir}/lib/idgenerator-spring-boot-starter-0.0.1.jar
</systemPath>
<scope>system</scope>
<version>0.0.1</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>- 编写测试类
@SpringBootTest
class DemoIdApplicationTests {
@Autowired
private IdGenService idGenService;
@Test
public void idGenTest() {
System.out.println("调用自定义序列号生成器 starter 生成的序列号为：" + idGenService.next());
}
}执行后控制台输出如下：
调用自定义序列号生成器 starter 生成的序列号为：6919868765123379201至此，自定义序列号生成器 starter 就验证通过了，收工。
4. 例行回顾
本文主要是基于 Spring Boot 封装一个序列号生成器服务 + Starter，只需通过封装的 Starter，就可以很轻松的在项目中生成全局唯一的序列 ID。
参考资料：
https://spring.io/
https://start.spring.io/
https://spring.io/projects/spring-boot
https://github.com/spring-projects/spring-boot
https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/
https://stackoverflow.com/questions/tagged/spring-boot
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原始发表：2022-04-21，如有侵权请联系 cloudcommunity@tencent.com 删除
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