10 lines - write to file most frequent words from .txt

printMostFrequentWords.java

public static void printMostFrequentWords() throws Exception {
    PrintWriter fileWriter = new PrintWriter("output.txt");
    List<String> words = Arrays.asList(new String(Files.readAllBytes(Paths.get("input.txt"))).split("\\s+"));
    words.stream().distinct()
            .map((word) -> String.join("", Arrays.asList(word.split("")).stream()
                            .filter((character) -> Character.isLetter(character.charAt(0)))
                            .collect(Collectors.toList())))
            .map((word) -> new AbstractMap.SimpleEntry<>(word, Collections.frequency(words, word)))
            .sorted(Collections.reverseOrder(Map.Entry.comparingByValue()))
            .forEach((entry) -> fileWriter.println(entry.getValue() + " - " + entry.getKey()));
    fileWriter.close();
}