在 ArrayList 中搜索单词<String>并将结果保存到 Map<String, Integer>

Question

I have some words in a List<String> and I want to iterate inside an ArrayList<String> , searching for matches and putting each of them (with their occurrences) in a Map<String, Integer> . I write this method:

public Map<String, Integer> findTheWords(ArrayList<String> textInFiles, List<String> words) {


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

            Map<String, Integer> mapResult = new HashMap<>();

            for (int j = 0; j < words.size(); j++) {

                    int count = 0;

                    Pattern regexp = Pattern.compile("\\b" + words.get(j) + "\\b");
                    Matcher matcher = regexp.matcher(textInFiles.get(i));

                     if(matcher.find()) {
                         while (matcher.find()) {
                            count++;
                        }

                        mapResult.put(textInFiles.get(i), count);
                     }

            }
        }

    return mapResult;               
    }

Problem is with count variable and inserting right value in the map

Answer 1

When you do matcher.find() , you're consuming an occurrence.

You have two solutions:

1) adding one when inserting, which isn't really clean and readable

2) test before you insert

int count = 0;
while (matcher.find()) {
     count++;
}
if (n>0) mapResult.put(textInFiles.get(i), count);