my encode and decode program cant seem to work what am i doing wrong here?

So I have this as my main program and i also have a util program. when i use the program with a text file it will only rename it but i dont think its encrypting my file contents. When I tested it out it would rename the file and print out the new context but when i used decode in the parameters it wouldnt decrypt the new message am i doing something wrong?

import java.io.File;
import java.io.FileNotFoundException;   
import java.util.Scanner;
import java.io.PrintWriter;
public class Prog4 {
    public static void main(String[] args){
         if (args.length != 3){
         System.out.println("Enter the right amount of arguments!");
         System.exit(0);
    }

    String command=args[0];
    String key= args[1];
    String fileName = args[2];
    File file = new File(args[2]);
    String fileExtention="";
    if(args[0].equals("encode")){
        fileExtention=".crypt"; 

    }
    else if (args[0].equals("decode")){
        fileExtention=".decrypt";
    }
    else{
        System.out.println("Enter decode or encode!");
        Syst`enter code here`em.exit(0);
    }   
    File newName = new File(fileName.substring(0,args[2].lastIndexOf("."))+fileExtention);
    try{
        Scanner sc= new Scanner(file);
        PrintWriter out = new PrintWriter(newName);
        if(args[0].equals("encode")){
            while (sc.hasNextLine()){
                Util4.encrypt(sc, out, key);
            }
        }
        else if (args[0].equals("decode")){
            while (sc.hasNextLine()){
                Util4.decrypt(sc, out, key);
            }
        }
        while (sc.hasNextLine()){
            int i = sc.nextInt();
            System.out.println(i);
        }
        sc.close();
    }
    catch(FileNotFoundException e){
        e.printStackTrace();


    }

}

} and this is my util

import java.io.PrintWriter;
import java.util.Scanner;


public class Util4 {
public static final int NUM_LETTERS = 26;
public static void encrypt(Scanner sc, PrintWriter out, String key){
    while(sc.hasNext()){
        char c;
        int k;
        String temporary="";
        String line = sc.nextLine();
        for (int i= 0; i< line.length(); ++i){
            temporary += shiftUpByK(c= line.charAt(i),k=key.charAt(i%key.length())-'a');
        }
        System.out.println(temporary);
        temporary="";
    }
}
public static void decrypt(Scanner sc, PrintWriter out, String key){
    while(sc.hasNext()){
        char c;
        int k;
        String temporary="";
        String line = sc.nextLine();
        for(int i = 0; i < line.length(); ++i){
            temporary += shiftDownByK(c=line.charAt(i), k=key.charAt(i%key.length())-'a');
        }
        System.out.println(temporary);
        System.out.flush();
        temporary="";

    }
}
// shifting up for the encoding process
public static char shiftUpByK(char c, int k) {
    if ('a' <= c && c <= 'z')
        return (char) ('a' + (c-'a' + k) % NUM_LETTERS);
    if ('A' <= c && c <= 'Z')
        return (char) ('A' + (c-'A' +k) % NUM_LETTERS);
            return c; // don't encrypt if not an alphabetic character
    }
// shifting down for the decoding process
public static char shiftDownByK(char c, int k) {
    return shiftUpByK(c, NUM_LETTERS-k);
}

}