如何在Java中同时对两个列表排序？

Question

我有两个列表：1.带单词2.带有各自的频率计数

现在，我想对两个列表进行降序排序，以使第一个列表中的单词索引与包含频率计数的第二个列表的索引匹配。

添加功能：

    public String[] process() throws Exception
   {

    String[] ret = new String[20];
    int c=0;

    BufferedReader br = new BufferedReader(new FileReader(inputFileName));
    String line = br.readLine();
    List<String> result  = new ArrayList<String>();
    List<Integer> sorted = new ArrayList<Integer>();
    List<String> key= new ArrayList<String>();
    List<String> new_list = new ArrayList<String>();
    int x=0;
    while(line!=null){
        StringTokenizer st = new StringTokenizer(line,delimiters);
        String token = "";
        while (st.hasMoreTokens()) {
            token = st.nextToken();
            //System.out.println(token);
            if(token!=null)
            {
            //System.out.println(token);
                result.add( x,token.toLowerCase());

            //System.out.println("Key is" + x + "\t" + result.get(x));
                x++;
            }
        }
        line=br.readLine();
    }
            for(int w =0;w<x;w++){
        c=0;
        String copy=result.get(w);
        int i;
        for(i =0;i<stopWordsArray.length;i++){
            if(copy.compareTo(stopWordsArray[i])==0){
      c=1;
      break;
      }
      }
     if(c==0){
      new_list.add(copy);
      }
      }
      if(c==0){

    Map<String, Integer> map = new HashMap<String, Integer>();
    for (String temp : new_list) {
    Integer count = map.get(temp);
    map.put(temp, (count == null) ? 1 : count + 1);
   }

int i=0;
int  sort = 0;
String key1 = "";
for (Map.Entry<String, Integer> entry : map.entrySet()) {
 sort = entry.getValue();
 key1 = entry.getKey();
 sorted.add(i,sort);
 key.add(i,key1);

 i++;
  }
   Integer maxi= Collections.max(sorted);
   System.out.println(maxi);
   Integer value = sorted.indexOf(maxi);
   System.out.println(value);
   System.out.println("Word is:"  + key.get(value));

   }
  return ret; }

这里排序的是包含单词频率的列表，而键是包含单词的列表。

Answer 1

一种选择是创建一个具有两个成员的类：单词和频率。 创建一个Comparator或实现Comparable以便根据频率进行排序，然后实现toString()来按您喜欢的方式进行打印。

Answer 2

我不完全了解这种情况，但是把它扔在那里。

您可以使用Map<String,Integer>将数据与映射Word-> Frequency一起存储。 现在，如果您使用TreeMap，它将根据关键字（您所用的单词）自动排序。 现在，如果要按值（频率）排序，请遵循此SOF Post- TreeMap按值排序

Answer 3

如果单词重复，地图将无法正常工作。 同一密钥的最后一个值将替换先前的那个。 因此，我想到的解决方案如下：

SortingWordAndCounts.java

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;

public class SortingWordAndCounts {

    public static void main(String args[]) {
        ArrayList<WordFreq> wordFreqList = new ArrayList<WordFreq>();

        for (int i = 10; i >= 0; i--) {
            WordFreq wf = new WordFreq();
            wf.setWord("Word" + (i + 1));
            wf.setFrequency(i + 10);
            wordFreqList.add(wf);
        }

        System.out.println("===== Unsorted Result=====");

        for (WordFreq wf : wordFreqList) {
            System.out.println(wf.word + "=" + wf.frequency);
        }

        System.out.println("===== sort by Word=====");
        // Now Sort list and print
        for (WordFreq wf : new SortingWordSAndCounts().sortByWord(wordFreqList,"DESC")) {

            System.out.println(wf.word + "=" + wf.frequency);

        }
System.out.println("===== sort by Frequency=====");

        // Now Sort list and print
        for (WordFreq wf : new SortingWordSAndCounts().sortByFrequency(wordFreqList,"DESC")) {

            System.out.println(wf.word + "=" + wf.frequency);

        }


    }

    public ArrayList<WordFreq> sortByWord(ArrayList<WordFreq> wordFreqList, String sortOrder) {
        Comparator<WordFreq> comparator = new Comparator<WordFreq>() {

            @Override
            public int compare(WordFreq o1, WordFreq o2) {

                if (sortOrder.equalsIgnoreCase("DESC"))
                    return o2.word.compareTo(o1.word);
                else
                    return o1.word.compareTo(o2.word);

            }
        };

        Collections.sort(wordFreqList, comparator);
        return wordFreqList;
    }

    public ArrayList<WordFreq> sortByFrequency(ArrayList<WordFreq> wordFreqList, String sortOrder) {
        Comparator<WordFreq> comparator = new Comparator<WordFreq>() {

            @Override
            public int compare(WordFreq o1, WordFreq o2) {

                if (sortOrder.equalsIgnoreCase("DESC"))

                    return o2.frequency - o1.frequency;
                else
                    return o1.frequency - o2.frequency;

            }
        };

        Collections.sort(wordFreqList, comparator);
        return wordFreqList;
    }

}

创建pojo：

WordFreq.java


public class WordFreq {

    String word;
    int frequency;
    public String getWord() {
        return word;
    }
    public void setWord(String word) {
        this.word = word;
    }
    public int getFrequency() {
        return frequency;
    }
    public void setFrequency(int frequency) {
        this.frequency = frequency;
    }

}

希望能帮助到你。