Core Java 书中讲集合的一段代码，有些疑问

[口香糖先森]

package execise.coreJava;

import java.util.HashSet;
import java.util.Iterator;
import java.util.Scanner;
import java.util.Set;

public class SetTest {
	public static void main(String[] args) {
		Set<String> words = new HashSet<>();
		
		long totalTime = 0;
		
		Scanner in = new Scanner(System.in);
		
		while(in.hasNext()) {
			
			String word = in.next();
			
			long callTime = System.currentTimeMillis();
			
			words.add(word);
			
			callTime = System.currentTimeMillis() - callTime;
			
			totalTime += callTime;
			
		}
		
		Iterator<String> iter = words.iterator();
		
		for(int i = 1; i <= 20 && iter.hasNext(); i++) 
			System.out.println(iter.next());
		System.out.println(". . .");
		System.out.println(words.size() + " distinct words." + totalTime + " milliseconds.");
	}
}

英文版的书中说：The program reads all words from the input and adds them to the hash set. It
then iterates through the unique words in the set and finally prints out a count.
(Alice in Wonderlandhas 5,909 unique words, including the copyright notice at the
beginning.) The words appear in random order.

但是我执行完这个代码 怎么都执行不到 30 行之后的输出，求解 是不是程序就是这样的啊，还是我没看明白？

[sleeplacker]

你需要按ctrl+z来结束输入，这样才能跳出while循环 (但是你的程序意思我不怎么明白)

[口香糖先森]

引用 1 楼 lg1544650023 的回复:

你需要按ctrl+z来结束输入，这样才能跳出while循环 (但是你的程序意思我不怎么明白)

感谢，就是你说的这个情况。