java通用自研接口限流组件

某业务中需要对后端接口进行限流，我们可以直接引入阿里巴巴的Sentinel快速实现，但是某企业中出于安全考虑，需要部门自己研发一套，可以采用Redis+Lua脚本+AOP+反射+自定义注解来实现
思路来源于链接

项目结构：
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启动类：不需要额外加东西，默认即可

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 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>3.4.3</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>org.example</groupId>
    <artifactId>my-rate-limit</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>my-rate-limit</name>
    <description>my-rate-limit</description>
    <url/>
    <licenses>
        <license/>
    </licenses>
    <developers>
        <developer/>
    </developers>
    <scm>
        <connection/>
        <developerConnection/>
        <tag/>
        <url/>
    </scm>
    <properties>
        <java.version>21</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-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-redis</artifactId>
            <version>3.1.0</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.9.22.1</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

application.properties：配置redis相关

spring.application.name=my-rate-limit
server.port=8081
# redis
spring.data.redis.database=0
spring.data.redis.host=127.0.0.1
spring.data.redis.port=6379
spring.data.redis.password=
spring.data.redis.lettuce.pool.max-active=8
spring.data.redis.lettuce.pool.max-wait=-1ms
spring.data.redis.lettuce.pool.max-idle=8
spring.data.redis.lettuce.pool.min-idle=0

RedisConfig：常规的序列化配置

package org.example.myratelimit.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.EnableAspectJAutoProxy;
import org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;

/**
 * RedisConfig
 * @author xiajunfeng
 * @date 2025/03/08
 */
@Configuration
@EnableAspectJAutoProxy //V2  开启AOP自动代理
public class RedisConfig
{
    /**
     * @param lettuceConnectionFactory
     * @return
     *
     * redis序列化的工具配置类，下面这个请一定开启配置
     * 127.0.0.1:6379> keys *
     * 1) "ord:102"  序列化过
     * 2) "\xac\xed\x00\x05t\x00\aord:102"   野生，没有序列化过
     */
    @Bean
    public RedisTemplate<String, Object> redisTemplate(LettuceConnectionFactory lettuceConnectionFactory)
    {
        RedisTemplate<String,Object> redisTemplate = new RedisTemplate<>();

        redisTemplate.setConnectionFactory(lettuceConnectionFactory);
        //设置key序列化方式string
        redisTemplate.setKeySerializer(new StringRedisSerializer());
        //设置value的序列化方式json
        redisTemplate.setValueSerializer(new GenericJackson2JsonRedisSerializer());

        redisTemplate.setHashKeySerializer(new StringRedisSerializer());
        redisTemplate.setHashValueSerializer(new GenericJackson2JsonRedisSerializer());

        redisTemplate.afterPropertiesSet();

        return redisTemplate;
    }
}

以上都为常规配置，配置完成后，开始写接口

RedisLimitController：接口中用到了自定义注解**@RedisLimitAnnotation**

package org.example.myratelimit.controller;

import lombok.extern.slf4j.Slf4j;
import org.example.myratelimit.annotation.RedisLimitAnnotation;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * RedisLimitController
 * @author xiajunfeng
 * @date 2025/03/08
 */
@Slf4j
@RestController
public class RedisLimitController {

    /**
     * 10秒内最多访问3次
     * @return
     */
    @GetMapping("/redis/limit/test")
    @RedisLimitAnnotation(key = "redisLimit", permitsPerSecond = 3, expire = 10, msg = "当前访问人数较多，请稍后再试，自定义提示！")
    public String redisLimit()
    {
        return "正常业务返回，订单流水：xxxx" ;
    }

}

RedisLimitAnnotation：自定义注解，定义了key、最大访问次数、过期窗口时间、限流出现提示语

package org.example.myratelimit.annotation;

import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * @author xiajunfeng
 */

@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.METHOD})
@Documented
public @interface RedisLimitAnnotation {
    /**
     * 资源的key,唯一
     * 作用：不同的接口，不同的流量控制
     */
    String key() default "";

    /**
     * 最多的访问限制次数
     */
    long permitsPerSecond() default 3;

    /**
     * 过期时间(计算窗口时间)，单位秒默认30
     */
    long expire() default 30;

    /**
     * 默认温馨提示语
     */
    String msg() default "default message:系统繁忙or你点击太快,请稍后再试，谢谢";
}

RedisLimitAop：使用AOP技术实现关键限流逻辑，调用了lua脚本

package org.example.myratelimit.aop;

import jakarta.annotation.PostConstruct;
import jakarta.annotation.Resource;
import lombok.extern.slf4j.Slf4j;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.reflect.MethodSignature;
import org.example.myratelimit.annotation.RedisLimitAnnotation;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.scripting.support.ResourceScriptSource;
import org.springframework.stereotype.Component;

import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;

/**
 * RedisLimitAop
 * @author xiajunfeng
 * @date 2025/03/08
 */
@Slf4j
@Aspect
@Component
public class RedisLimitAop {
    Object result = null;

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    /**
     *  redis调用lua脚本
     */
    private DefaultRedisScript<Long> redisLuaScript;
    @PostConstruct
    public void init(){
        redisLuaScript = new DefaultRedisScript<>();
        redisLuaScript.setResultType(Long.class);
        redisLuaScript.setScriptSource(new ResourceScriptSource(new ClassPathResource("rateLimiter.lua")));
    }

    @Around("@annotation(org.example.myratelimit.annotation.RedisLimitAnnotation)")
    public Object around(ProceedingJoinPoint joinPoint){
        MethodSignature signature = (MethodSignature) joinPoint.getSignature();
        Method method = signature.getMethod();

        RedisLimitAnnotation redisLimitAnnotation = method.getAnnotation(RedisLimitAnnotation.class);
        // redis key
        String key = redisLimitAnnotation.key();
        // @RedisLimitAnnotation中的key不能为空
        if(key == null){
            throw new RuntimeException("请在注解属性中定义key");
        }
        // 最多的访问限制次数
        long limit = redisLimitAnnotation.permitsPerSecond();
        // 过期时间(计算窗口时间)
        long expire = redisLimitAnnotation.expire();
        // redis key 数组
        List<String> keys = new ArrayList<>();
        keys.add(key);

        // 执行lua脚本后的返回结果
        Long count = stringRedisTemplate.execute(
            redisLuaScript,
            keys,
            String.valueOf(limit),
            String.valueOf(expire)
        );
        // 如果结果为0，证明已经成功运行限流功能
        if (count == 0) {
            System.out.println("启动了限流功能，key: "+key);
            // 返回@RedisLimitAnnotation中自定义的msg内容
            return redisLimitAnnotation.msg();
        }

        try {
            //放行
            result = joinPoint.proceed();
        } catch (Throwable e) {
            throw new RuntimeException(e);
        }

        return result;
    }

}

rateLimiter.lua：

--获取KEY,针对那个接口进行限流，Lua脚本中的数组索引默认是从1开始的而不是从零开始。
local key = KEYS[1]
--获取注解上标注的限流次数
local limit = tonumber(ARGV[1])

local curentLimit = tonumber(redis.call('get', key) or "0")

--超过限流次数直接返回零，否则再走else分支
if curentLimit + 1 > limit
then return 0
-- 首次直接进入
else
    -- 自增长 1
    redis.call('INCRBY', key, 1)
    -- 设置过期时间
    redis.call('EXPIRE', key, ARGV[2])
    return curentLimit + 1
end

--@RedisLimitAnnotation(key = "redisLimit", permitsPerSecond = 2, expire = 1, msg = "当前排队人数较多，请稍后再试！")

编写完成后，启动服务，访问http://localhost:8081/redis/limit/test，我的自定义注解配置为@RedisLimitAnnotation(key = “redisLimit”, permitsPerSecond = 3, expire = 10, msg = “当前访问人数较多，请稍后再试，自定义提示！”)
即10秒内最多访问3次，浏览器快速访问这个接口三次，浏览器出现错误提示，成功！
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