Не могу понять в чем причина. Код свою функцию выполняет
package com.javarush.task.task19.task1923;
import java.io.*;
/*
Слова с цифрами
*/
public class Solution {
public static void main(String[] args) throws IOException {
StringBuilder stringBuilder = new StringBuilder();
for (String part : args) {
stringBuilder.append(" " + part);
}
String[] fileNames = stringBuilder.toString().split(".txt");
String fileName1 = fileNames[0].trim() + ".txt";
String fileName2 = fileNames[1].trim() + ".txt";
BufferedReader fileReader = new BufferedReader(new FileReader(fileName1));
BufferedWriter fileWriter = new BufferedWriter(new FileWriter(fileName2));
while (fileReader.ready()) {
String[] line = fileReader.readLine().split(" ");
for (int i = 0; i < line.length; i++) {
for (char c : line[i].toCharArray()) {
if (Character.isDigit(c)) {
if (!fileReader.ready() && i == line.length - 1) {
fileWriter.write(line[i]);
} else fileWriter.write(line[i] + " ");
}
}
}
}
fileReader.close();
fileWriter.close();
}
}