SpringBoot +Redis/Guava 实现布隆过滤器
import com.google.common.hash.BloomFilter;
import com.google.common.hash.Funnels;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.ValueOperations;
import org.springframework.stereotype.Component;
import javax.annotation.PostConstruct;
@Component
public class BloomFilterHelper {
@Autowired
private StringRedisTemplate redisTemplate;
private ValueOperations<String, String> opsForValue;
private BloomFilter<Integer> bloomFilter;
@PostConstruct
private void init() {
opsForValue = redisTemplate.opsForValue();
bloomFilter = BloomFilter.create(Funnels.integerFunnel(), 1000000, 0.01);
// 如果已有布隆过滤器数据,则重新构建布隆过滤器
String bloomFilterData = opsForValue.get("bloomFilterData");
if (bloomFilterData != null) {
bloomFilterData.split(",").forEach(number -> bloomFilter.put(Integer.parseInt(number)));
}
}
public boolean mightContain(int value) {
return bloomFilter.mightContain(value);
}
public void put(int value) {
bloomFilter.put(value);
opsForValue.set("bloomFilterData", String.join(",", bloomFilter.asSet().stream().map(Object::toString).collect(Collectors.toList())));
}
}
这个代码示例使用了Guava的BloomFilter类来创建布隆过滤器,并且将其存储在Redis中。mightContain
方法用于检查元素是否可能存在于布隆过滤器中,而put
方法用于将元素添加到布隆过滤器中并更新Redis中的数据。这个示例展示了如何在Spring Boot应用中使用布隆过滤器,并且如何通过Redis来持久化布隆过滤器的数据。
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