Ткните носом..
package com.javarush.task.task19.task1925;
/*
Длинные слова
*/
import java.io.*;
public class Solution {
public static void main(String[] args) throws IOException {
BufferedReader fileReader = new BufferedReader(new FileReader(args[0]));
BufferedWriter fileWriter = new BufferedWriter(new FileWriter(args[1]));
while (fileReader.ready()) {
String line = fileReader.readLine();
String newLine = "";
String[] temp = line.split(" ");
for (String word : temp) {
if (word.length() > 6) {
newLine += word + " ";
}
}
fileWriter.write(newLine.trim().replaceAll(" ", ","));
}
fileReader.close();
fileWriter.close();
}
}