Redis BloomFilter实例讲解

<dependency>
   <groupId>com.google.guava</groupId>
   <artifactId>guava</artifactId>
   <version>30.1.1-jre</version>
</dependency>

import com.google.common.hash.BloomFilter;
import com.google.common.hash.Funnels;
import lombok.extern.slf4j.Slf4j;

/**
 * 布隆过滤器简单实现
 * @author ludangxin
 * @date 2021/8/16
 */
@Slf4j
public class BloomFilterTest {
   /**
    * 预计要插入元素个数
    */
   private static final int SIZE = 1000000;
   /**
    * 误判率
    */
   private static final double FPP = 0.01;
   /**
    * 布隆过滤器
    */
   private static final BloomFilter<Integer> BLOOMFILTER = BloomFilter.create(Funnels.integerFunnel(), SIZE, FPP);

   public static void main(String[] args) {
      //插入数据
      for (int i = 0; i < 1000000; i++) {
         BLOOMFILTER.put(i);
      }
      int count = 0;
      // 过滤判断
      for (int i = 1000000; i < 3000000; i++) {
         if (BLOOMFILTER.mightContain(i)) {
            count++;
            log.info(i + "误判了");
         }
      }
      log.info("总共的误判数:" + count);
   }
}

<dependency>
   <groupId>org.redisson</groupId>
   <artifactId>redisson-spring-boot-starter</artifactId>
   <version>3.16.1</version>
</dependency>

import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RBloomFilter;
import org.redisson.api.RedissonClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * redisson 布隆过滤器实现
 *
 * @author ludangxin
 * @date 2021/8/16
 */
@Slf4j
@RestController
@RequestMapping("bloomFilter")
@RequiredArgsConstructor
public class BloomFilterWithRedisson {
   private final RedissonClient redissonClient;

   /**
    * 预计要插入元素个数
    */
   private static final long SIZE = 1000000L;
   /**
    * 误判率
    */
    private static final double FPP = 0.01;

   /**
    * 自定义布隆过滤器的 key
    */
   private static final String BLOOM_FILTER_KEY = "bloomFilter";

   /**
    * 向布隆过滤器中添加数据, 模拟向布隆过滤器中添加10亿个数据
    */
   @GetMapping
   public void filter() {
     // 获取布隆过滤器
      RBloomFilter<Integer> bloomFilter = redissonClient.getBloomFilter(BLOOM_FILTER_KEY);
      // 初始化，容量为100万， 误判率为0.01
      bloomFilter.tryInit(SIZE, FPP);
      // 模拟向布隆过滤器中添加100万个数据
      for (int i = 0; i < SIZE; i++) {
          bloomFilter.add(i);
      }
      int count = 0;
      // 过滤判断
      for (int i = 1000000; i < 3000000; i++) {
         if (bloomFilter.contains(i)) {
            count++;
            log.info(i + "误判了");
         }
      }
      log.info("size:" + bloomFilter.getSize());
      log.info("总共的误判数:" + count);
   }
}