java实现两个文本相似度 simHash 实现

java实现两个文本相似度 simHash 实现

// An highlighted block
package com.timefinance.admin.common.util;

import com.hankcs.hanlp.HanLP;
import org.jsoup.Jsoup;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.stream.Collectors;

public class SimilarityUtil {
    /**
     * 获得两个句子的相似度
     *
     * @param sentence1
     * @param sentence2
     * @return
     */
    public static double getSimilarity(String sentence1, String sentence2) {
        List<String> sent1Words = getSplitWords(sentence1);
        List<String> sent2Words = getSplitWords(sentence2);
    System.out.println(sent1Words);
    System.out.println(sent2Words);
    
        List<String> allWords = mergeList(sent1Words, sent2Words);

        int[] statistic1 = statistic(allWords, sent1Words);
        int[] statistic2 = statistic(allWords, sent2Words);

        double dividend = 0;
        double divisor1 = 0;
        double divisor2 = 0;
        for (int i = 0; i < statistic1.length; i++) {
            dividend += statistic1[i] * statistic2[i];
            divisor1 += Math.pow(statistic1[i], 2);
            divisor2 += Math.pow(statistic2[i], 2);
        }

        return dividend / (Math.sqrt(divisor1) * Math.sqrt(divisor2));
    }

    private static int[] statistic(List<String> allWords, List<String> sentWords) {
        int[] result = new int[allWords.size()];
        for (int i = 0; i < allWords.size(); i++) {
            result[i] = Collections.frequency(sentWords, allWords.get(i));
        }
        return result;
    }

    private static List<String> mergeList(List<String> list1, List<String> list2) {
        List<String> result = new ArrayList<>();
        result.addAll(list1);
        result.addAll(list2);
        return result.stream().distinct().collect(Collectors.toList());
        
    }

    private static List<String> getSplitWords(String sentence) {
        // 去除掉html标签
        sentence = Jsoup.parse(sentence.replace("&nbsp;","")).body().text();
        // 标点符号会被单独分为一个Term，去除之
        return HanLP.segment(sentence).stream().map(a -> a.word).filter(s -> !"`~!@#$^&*()=|{}':;',\\[\\].<>/?~！@#￥……&*（）——|{}【】‘；：”“'。，、？ ".contains(s)).collect(Collectors.toList());
    }

     
}