Funkcja do wykorzystania w zadaniu drugim

static String readFile(String name, Charset charset){
   StringBuilder s = new StringBuilder();
   try( BufferedReader file = new BufferedReader(new InputStreamReader( new FileInputStream(name), charset))){
       for(;;){
           int c=file.read();
           if(c<0)break;
           s.append((char)c);
       }
       return s.toString();
   }
   catch (IOException ex) {
       ex.printStackTrace();
   }
   return "";
}