что не так то?
package com.javarush.task.task22.task2211;
import java.io.*;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Paths;
/*
Смена кодировки
*/
public class Solution {
public static void main(String[] args) throws IOException {
// Files.write(Paths.get(args[0]), Files.readAllLines(Paths.get(args[1])), StandardCharsets.UTF_8);
FileInputStream fis = new FileInputStream(args[0]);
FileOutputStream fos = new FileOutputStream(args[1]);
byte [] buff = new byte[fis.available()];
while (fis.available()>0) {
fis.read(buff);
}
fos.write(new String(buff).getBytes(StandardCharsets.UTF_8));
fis.close();
fos.close();
}
}