我正试图从下面的代码打印这些密钥。当我使用string.join时，它不会用逗号和空格分隔它们，而是作为一个单词。不知道我做错了什么。

String[] words = scanner.nextLine().toLowerCase().split(" ");

LinkedHashMap<String, Integer> count = new LinkedHashMap<>();

for (int i = 0; i < words.length; i++) {

    Integer occurrences = count.get(words[i]);
    if (occurrences == null) {
        occurrences = 0;
    }
    count.put(words[i], occurrences + 1);
}
for (Map.Entry<String, Integer> entry : count.entrySet()) {
    if (entry.getValue() % 2 != 0) {
        System.out.print(String.join(", ", entry.getKey()));
    }
}

} }