BloomFilter.java

import java.util.BitSet;

/*
 * @author: Ankit.Maurya
 */

public class BloomFilter {

	BitSet bitset = null;
	int numOfHashFun;
	int bfSize;
	int hash1, hash2;
	int collisionCount;
	CustomHashFunction chf;

	public BloomFilter(int _bitset, int _numOfHashFun) {
		chf = new CustomHashFunction();
		this.bitset = new BitSet(_bitset);
		bitset.clear();
		this.numOfHashFun = _numOfHashFun;
		bfSize = bitset.size();
		collisionCount = 0;
	}

	public boolean isPresent(String x) {
		hash1 = chf.getHash(x);
		hash2 = chf.getHash2(x);
		for (int i = 1; i <= numOfHashFun; i++) {
			if (bitset.get(Math.abs((hash1 + i * hash2) % bfSize)))
				continue;
			else
				return false;
		}
		return true;
	}

	public void add(String x) {

		if (isPresent(x)){
			collisionCount++;
		System.out.println(collisionCount);	
		}
		hash1 = chf.getHash(x);
		hash2 = chf.getHash2(x);
		for (int i = 1; i < numOfHashFun; i++) {
			bitset.set(Math.abs((hash1 + i * hash2) % bfSize));
		}
	}
}

CustomHashFunction.java

package bloomfilter;

/*
 * @author: Ankit.Maurya
 */
public class CustomHashFunction {

	public int getHash(String x) {
		int prime = 31;
		String s = "upgrad";
		int _tempHashCode = 1;
		int hash = x.hashCode();
		for (int i = 0; i < s.length(); i++)
			_tempHashCode = (prime * _tempHashCode) + s.charAt(i) + hash;
		return _tempHashCode;
	}

	public int getHash2(String x) {
		int prime = 73;
		String s = "blooming";
		int _tempHashCode = 1;
		int hash = x.hashCode();
		for (int i = 0; i < s.length(); i++)
			_tempHashCode = (prime * _tempHashCode) + s.charAt(i) + hash;
		return _tempHashCode;
	}
}

Main.java

import java.io.BufferedReader;
import java.io.FileReader;

/*
 * @author: Ankit.Maurya
 */

public class Main {

	public static void main(String[] args) {
		String name = "src/resources/top10milliondomains.csv";
		String domain = null;
		try {
			BufferedReader brObj = new BufferedReader(new FileReader(name));
			BloomFilter bloomFilter = new BloomFilter(45227937, 30);

			while ((domain = brObj.readLine()) != null) {
				// System.out.println(domain.replaceAll("\"",
				// "").split(",")[1]);
				bloomFilter.add(domain.replaceAll("\"", "").split(",")[1]);
			}
			System.out.println("Done Adding");
			String newUrl = "abc1236.com";
			if (bloomFilter.isPresent(newUrl))
				System.out.println("Already Present");
			else
				System.out.println("Yeahhhh, You can use this.");
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

}