前言

业务中需要对一些接口进行限流处理，防止机器人调用或者保证服务质量；

实现方式

• 基于redis的lua脚本

引入依赖

<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-redis</artifactId>
</dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-aop</artifactId>
</dependency>

redis配置

package com.qiangesoft.wechat.config;import org.springframework.cache.annotation.CachingConfigurerSupport;
import org.springframework.cache.annotation.EnableCaching;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.data.redis.serializer.StringRedisSerializer;/*** redis配置** @author qiangesoft* @date 2024-03-19*/
@Configuration
@EnableCaching
public class RedisConfig extends CachingConfigurerSupport {@Bean@SuppressWarnings(value = {"unchecked", "rawtypes"})public RedisTemplate<Object, Object> redisTemplate(RedisConnectionFactory connectionFactory) {RedisTemplate<Object, Object> template = new RedisTemplate<>();template.setConnectionFactory(connectionFactory);FastJson2JsonRedisSerializer serializer = new FastJson2JsonRedisSerializer(Object.class);// 使用StringRedisSerializer来序列化和反序列化redis的key值template.setKeySerializer(new StringRedisSerializer());template.setValueSerializer(serializer);// Hash的key也采用StringRedisSerializer的序列化方式template.setHashKeySerializer(new StringRedisSerializer());template.setHashValueSerializer(serializer);template.afterPropertiesSet();return template;}@Beanpublic DefaultRedisScript<Long> limitScript() {DefaultRedisScript<Long> redisScript = new DefaultRedisScript<>();redisScript.setScriptText(limitScriptText());redisScript.setResultType(Long.class);return redisScript;}/*** 限流脚本*/private String limitScriptText() {return "local key = KEYS[1]\n" +"local count = tonumber(ARGV[1])\n" +"local time = tonumber(ARGV[2])\n" +"local current = redis.call('get', key);\n" +"if current and tonumber(current) > count then\n" +"    return tonumber(current);\n" +"end\n" +"current = redis.call('incr', key)\n" +"if tonumber(current) == 1 then\n" +"    redis.call('expire', key, time)\n" +"end\n" +"return tonumber(current);";}
}

限流注解

package com.qiangesoft.wechat.config;import java.lang.annotation.*;/*** 限流注解** @author qiangesoft* @date 2024-03-19*/
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface RateLimiter {/*** 限流类型*/LimitType limitType() default LimitType.IP;/*** 限流时间,单位秒*/int time() default 60;/*** 限流次数*/int count() default 10;}

限流实现

package com.qiangesoft.wechat.config;import com.qiangesoft.wechat.utils.IpUtil;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.script.RedisScript;
import org.springframework.stereotype.Component;import java.lang.reflect.Method;
import java.util.Collections;
import java.util.List;/*** 限流处理** @author qiangesoft* @date 2024-03-19*/
@RequiredArgsConstructor
@Slf4j
@Aspect
@Component
public class RateLimiterAspect {private final RedisTemplate<Object, Object> redisTemplate;private final RedisScript<Long> limitScript;@Before("@annotation(rateLimiter)")public void doBefore(JoinPoint point, RateLimiter rateLimiter) throws Throwable {int time = rateLimiter.time();int count = rateLimiter.count();String key = this.buildKey(rateLimiter, point);List<Object> keys = Collections.singletonList(key);try {Long number = redisTemplate.execute(limitScript, keys, count, time);if (number == null || number.intValue() > count) {throw new RuntimeException("访问过于频繁，请稍候再试");}} catch (RuntimeException e) {throw e;} catch (Exception e) {throw new RuntimeException("服务器限流异常，请稍候再试");}}/*** 缓存key** @param rateLimiter* @param point* @return*/public String buildKey(RateLimiter rateLimiter, JoinPoint point) {String limitId = "";if (rateLimiter.limitType() == LimitType.IP) {limitId = IpUtil.getIpAddr();}MethodSignature signature = (MethodSignature) point.getSignature();Method method = signature.getMethod();Class<?> targetClass = method.getDeclaringClass();String key = "rate_limit:" + limitId + "-" + targetClass.getName() + "-" + method.getName();return key;}
}

测试代码

package com.qiangesoft.wechat.controller;import com.qiangesoft.wechat.config.RateLimiter;
import com.qiangesoft.wechat.utils.ResultVO;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;/*** 测试接口** @author qiangesoft* @date 2024-03-19*/
@RestController
public class TestController {@RateLimiter@GetMapping("/test")public ResultVO test() {return ResultVO.ok("调用成功！");}}

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