Подскажите,как написать графический интерфейс!

import java.util.Random;
import java.util.Scanner;
 
public class Vernem {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("Input text: ");
        String text = scanner.nextLine();
        char[] achText = text.toCharArray();
        char[] achKey = new char[achText.length];
        char[] achResult = new char[achText.length];
        Random random = new Random();
        for (int i = 0; i < achText.length; i++) {
            achKey[i] = (char) random.nextInt(Character.MAX_VALUE);
            achResult[i] = (char) (achText[i] ^ achKey[i]);
        }
 
        System.out.println("Text: " + String.valueOf(achText));
        System.out.println("Key: " + String.valueOf(achKey));
        System.out.println("Result: " + String.valueOf(achResult));
        
        char[] achDecrypt = new char[achText.length];
        for (int i = 0; i < achText.length; i++) {
            achDecrypt[i] = (char) (achResult[i] ^ achKey[i]);
        }
        
        System.out.println("Decrypt: " + String.valueOf(achDecrypt));
    }
}

interface Vernem {
char [] encrypt(char [] src, char [] key);
char [] decrypt(char [] src, char [] key);
}