计算ArrayList中单词的出现次数

import java.util.ArrayList;
import java.util.HashMap;

public class WordCount {
    public static void main(String[] args) {
        ArrayList<String> words = new ArrayList<String>();
        words.add("hello");
        words.add("world");
        words.add("java");
        words.add("is");
        words.add("awesome");

        HashMap<String, Integer> wordCount = new HashMap<String, Integer>();

        for (String word : words) {
            if (wordCount.containsKey(word)) {
                wordCount.put(word, wordCount.get(word) + 1);
            } else {
                wordCount.put(word, 1);
            }
        }

        ArrayList<String> result = new ArrayList<String>();
        for (String word : wordCount.keySet()) {
            result.add(word + " : " + wordCount.get(word));
        }

        System.out.println(result);
    }
}

[hello : 1, world : 1, java : 1, is : 1, awesome : 1]