如何遍历哈希映射并放入数组/列表结构？

Question

Thank you for reading my post. Currently I am doing a school project and am unfortunately stuck. I have a hashmap of types that I would like to be able to iterate through and put into an array/list structure. Instead of using Map.Entry I have a helper class to make the code a little less tricky (im still tricked).

Helper Class:

    class WordCount {

        String word;
        Integer count;

        WordCount(String word, Integer count) {
            this.word = word;
            this.count = count;
        }
    }

and I have tried this:

WordCount[] wc = new WordCount[hm.size()];
Iterator it = hm.entrySet().iterator();
int i = 0;
while (it.hasNext()) {
    Map.Entry pair = (Map.Entry) it.next();
    wc[i].word = (String) pair.getKey();
    wc[i].count = (Integer) pair.getValue();
    i++;
}

I get errors with that code however. I have a feeling there is a much easier way to go about this...

Answer 1

If you want to shift the values of Hashmap to an array the easiest way i can think off is

ArrayList<Elements> list =
    new ArrayList<Elements>(myHashMap.values());

Answer 2

In java 8 :

 List<WordCount> words = hm.entrySet().stream()
                            .map(e -> new WordCount(e.getKey(), e.getValue()))
                            .collect(Collectors.toList());

Answer 3

List<WordCount> wordcounts = new ArrayList<>();  

for (String s : hm.keySet()) {
    int count = hm.get(s);
    WordCount w = new WordCount(s,count);
    wordcounts.add(w);
}