布隆过滤器使用举例

 

import com.google.common.collect.Lists;
import com.google.common.hash.BloomFilter;
import com.google.common.hash.Funnels;
import lombok.extern.slf4j.Slf4j;
import org.junit.Test;

import java.nio.charset.Charset;
import java.util.Arrays;
import java.util.List;
import java.util.stream.Collectors;

@Slf4j
public class TestBloomFilter {
    // 定义布隆过滤器
    BloomFilter<String> bloomFilter = BloomFilter.create(Funnels.stringFunnel(Charset.defaultCharset()), 100, 0.01);

    @Test
    public void test() {
        // 生成样本
        for (int i = 1; i <= 100; i++) {
            bloomFilter.put("" + i);
        }

        // 待测数据
        List<String> list = Arrays.asList("90", "100", "101", "200");

        // 筛选出样本中已存在的数据
        List<String> containList = Lists.newArrayList();
        containList = list.stream().filter(x -> bloomFilter.mightContain(x)).collect(Collectors.toList());

        // containList:[90, 100]
        log.info("containList:{}", containList.toString());
    }
}