使用正则表达式提取所有唯一词

/*
 from nowjava - 时  代  Java 
*/

     

import java.util.Arrays;

import java.util.Scanner;

import java.util.TreeSet;


public class ExtractAllUniqueWords {


    public static void main(String[] args) {



            Scanner input = new Scanner(System.in);


            String[] words = input.nextLine().toLowerCase().split("[\\W\\d]+");


            TreeSet<String> uniqueWords = new TreeSet<>(Arrays.asList(words));


            for (String word : uniqueWords) {/