Почему может не проходить валидатор? С моим тестовым файлом работает.
package com.javarush.task.task19.task1923;
/*
Слова с цифрами
*/
import java.io.*;
public class Solution {
public static void main(String[] args) throws IOException {
FileReader fileReader = new FileReader(args[0]);
FileWriter fileWriter = new FileWriter(args[1]);
//BufferedReader bufferedReader = new BufferedReader(new FileReader("C:/tst/1.txt"));
//BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter("C:/tst/2.txt"));
BufferedReader bufferedReader = new BufferedReader(fileReader);
BufferedWriter bufferedWriter = new BufferedWriter(fileWriter);
boolean firstWrite = true;
while (bufferedReader.ready()){
String[] temp = bufferedReader.readLine().split(" ");
for (String s: temp){
if (!s.matches("\\D+")){
if (!firstWrite) bufferedWriter.write(" ");
bufferedWriter.write(s);
firstWrite=false;
}
}
}
fileReader.close();
fileWriter.close();
}
}