I don't see what's wrong.
package com.codegym.task.task19.task1925;
/*
Long words
*/
import java.io.*;
import java.util.ArrayList;
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]));
ArrayList<String> list = new ArrayList<>();
while (fileReader.ready()) {
String[] array = fileReader.readLine().split("\\n");
fileReader.close();
for(String s : array)
{
if(s.length() > 6)
{
list.add(s);
}
}
fileWriter.write(list.get(0));
for(int i = 1; i < list.size(); i++)
{
fileWriter.write("," + list.get(i));
}
}
fileWriter.close();
}
}