玩转 Spring Boot 应用篇（序列号生成器服务实现）（十九）

2022-09-23 20:50:15 浏览数 (1)

0. 

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
代码语言：javascript复制
<?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。

代码语言：javascript复制
### 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。

代码语言：javascript复制
-- moudle taglocal tag = KEYS[1];if tag == nil then    tag = 'default';end-- if user do not pass shardId, default partition is 0.local partitionif 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 millisecondif count == step then    redis.call('PEXPIRE', seqKey, 1);end
local now = redis.call('TIME');-- second, microSecond, partition, seqreturn { 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。

代码语言：javascript复制
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;
@Configurationpublic 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）
代码语言：javascript复制
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）
代码语言：javascript复制
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;
@Servicepublic 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）
代码语言：javascript复制
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;
@RestControllerpublic 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
代码语言：javascript复制
<?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
代码语言：javascript复制
 ### 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
代码语言：javascript复制
-- moudle taglocal tag = KEYS[1];if tag == nil then    tag = 'default';end-- if user do not pass shardId, default partition is 0.local partitionif 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 millisecondif count == step then    redis.call('PEXPIRE', seqKey, 1);end
local now = redis.call('TIME');-- second, microSecond, partition, seqreturn { tonumber(now[1]), tonumber(now[2]), partition, count }
  • 编写 Service 以及实现
代码语言：javascript复制
package org.idgenerator.service;
/** * 序列号生成器 Service */public interface IdGenService {    String next();}
代码语言：javascript复制
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;
@Servicepublic 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
代码语言：javascript复制
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。

代码语言：javascript复制
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。
代码语言：javascript复制
<?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
代码语言：javascript复制
@SpringBootTestclass 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：

代码语言：javascript复制
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。

spring springboot lua java 云数据库Redis

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