Springboot 在 redis 中使用 BloomFilter 布隆过滤器机制

一、导入SpringBoot依赖

在pom.xml文件中，引入Spring Boot和Redis相关依赖

<!-- Google Guava 使用google的guava布隆过滤器实现--><dependency><groupId>com.google.guava</groupId><artifactId>guava</artifactId><version>30.1-jre</version></dependency>

二、配置布隆过滤器

创建一个布隆过滤器配置类BloomFilterConfig:

import com.google.common.hash.BloomFilter;
import com.google.common.hash.Funnels;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;@Configuration
public class BloomFilterConfig {@Beanpublic BloomFilter<String> bloomFilter() {return BloomFilter.create(Funnels.stringFunnel(Charset.defaultCharset()), 1000000, 0.01);}
}

三、实现缓存服务

创建一个BloomFilterController。使用布隆过滤器判断数据是否存在，从而避免缓存穿透：

package com.springboot3.test;import com.google.common.hash.BloomFilter;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;@RestController
@Controller
public class BloomFilterController {@Autowiredprivate BloomFilter bloomFilter;@Autowiredprivate RedisTemplate redisTemplate;@GetMapping("/cache/{key}")public String getCacheValue(@PathVariable String key) {boolean result = bloomFilter.mightContain(key);if(result==true){Object obj = redisTemplate.opsForValue().get(key);return obj.toString();}return "Cache miss, and the key does not exist in database.";}@GetMapping("/cache/{key}/{value}")public String setCacheValue(@PathVariable String key, @PathVariable String value) {bloomFilter.put(key);return "Cache set successfully.";}}

四、测试

向里面添加元素

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