Java - 如何从句子的 ArrayList 中获取每个单词

Question

例如，如何检查 listcontainsThese 中的单词是否存在于 listsentences 中以及有多少？

List<String> sentences = Arrays.asList("wish you a good day", "warm day", "sounds good");

List<String> containsThese = Arrays.asList("cool", "day", "good");

我在做什么：

for (int i = 0; i < sentences.size(); i++){

   String words = sentences.get(i);

   // so here I have each sentence separately
   // but how to iterate through it and add each word to another ArrayList or something?
   // so later can compare to it to 'containsThese' ?

}

欢迎提出建议，谢谢。

Answer 1

使用下面的函数，您可以在每个空格处拆分一个句子并将单词添加到一个新列表中。

private List<String> sentenceToList(String sentence) {
  return new ArrayList<>(Arrays.asList(sentence.split("\\s+")));
}

使用此函数，您将获得一个 Map，它以句子为键和一个列表，其中包含来自 containsThese 的所有单词。

private Map<String, List<String>> checkSentences() {
    Map<String, List<String>> containsMap = new HashMap<>();
    sentences.forEach(sentence -> {
        containsMap.put(sentence, sentenceToList(sentence).stream().distinct().filter(word -> containsThese.contains(word)).collect(Collectors.toList()));
    });
    return containsMap;
}

返回 -> {warm day=[day], sounds good=[good], wish you a good day=[good, day]}

Answer 2

为了获得最佳性能，首先构建句子中所有单词的Set，然后计算可以在集合中找到的单词。

List<String> sentences = Arrays.asList("wish you a good day", "warm day", "sounds good");
List<String> containsThese = Arrays.asList("cool", "day", "good");

Set<String> words = sentences.stream()
        .flatMap(Pattern.compile("\\s+")::splitAsStream)
        .collect(Collectors.toSet());
long wordsFound = containsThese.stream()
        .filter(words::contains)
        .count();

System.out.printf("Sentences contains %d of %d words%n", wordsFound, containsThese.size());

输出

Sentences contains 2 of 3 words

Answer 3

List<String> sentences = ArrayList<String>("wish you a good day", "warm day", "sounds good");
Iterator itr=sentences.iterator();
while(itr.hasNext()){
String s=itr.next();
}