java - 将多个值添加到 HashMap 中的一个键

Question

我正在开发一个项目，我将获得两个文件；一个是杂乱的单词，另一个是真实的单词。然后，我需要按字母顺序打印出困惑的单词列表，并在其旁边显示匹配的真实单词。问题是每个困惑的单词可能有多个真实的单词。

例如:

cta猫

ezrba 斑马

psot 帖子停止

我完成了该程序，没有考虑每个困惑单词的多个单词，因此在我的 HashMap 中我必须将 更改为 < String , List < String >> ，但这样做后我遇到了一些错误在 .get 和 .put 方法中。如何为每个困惑的单词的每个键存储多个单词？感谢您的帮助。

我的代码如下:

import java.io.*;
import java.util.*;

public class Project5
{
    public static void main (String[] args) throws Exception
    {

        BufferedReader dictionaryList = new BufferedReader( new FileReader( args[0] ) );
        BufferedReader scrambleList = new BufferedReader( new FileReader( args[1] ) );

        HashMap<String, List<String>> dWordMap = new HashMap<String, List<String>>(); 

        ArrayList<String> scrambled = new ArrayList<String>();

        while (dictionaryList.ready())
        {
            String word = dictionaryList.readLine();

            //throw in an if statement to account for multiple words
            dWordMap.put(createKey(word), word);
        }
        dictionaryList.close();

        ArrayList<String> scrambledList = new ArrayList<String>();

        while (scrambleList.ready())
        {
            String scrambledWord = scrambleList.readLine();

            scrambledList.add(scrambledWord);
        }
        scrambleList.close();

        Collections.sort(scrambledList);

        for (String words : scrambledList)
        {
            String dictionaryWord = dWordMap.get(createKey(words));
            System.out.println(words + " " + dictionaryWord);
        }

    }   

    private static String createKey(String word)
    {
        char[] characterWord = word.toCharArray(); 
        Arrays.sort(characterWord);
        return new String(characterWord);
    }  
}

Answer 1

你可以这样做:

替换行:

dWordMap.put(createKey(word), word);

与:

String key = createKey(word);
List<String> scrambled = dWordMap.get(key);

//make sure that scrambled words list is initialized in the map for the sorted key.
if(scrambled == null){
    scrambled = new ArrayList<String>();
    dWordMap.put(key, scrambled);
}

//add the word to the list
scrambled.add(word);