Base64 UUID

import java.nio.ByteBuffer;
import java.util.Base64;
import java.util.UUID;

public class Base64ToUUID {

    // Method to convert UUID to base64 (without padding)
    public static String uuidToBase64(UUID uuid) {
        ByteBuffer byteBuffer = ByteBuffer.wrap(new byte[16]);
        byteBuffer.putLong(uuid.getMostSignificantBits());
        byteBuffer.putLong(uuid.getLeastSignificantBits());
        String base64 = Base64.getEncoder().encodeToString(byteBuffer.array());
        return base64.replaceAll("=+$", ""); // Remove padding
    }

    // Method to convert base64 back to UUID
    public static UUID base64ToUUID(String base64) {
        // Add padding back if necessary
        String base64WithPadding = base64;
        while (base64WithPadding.length() % 4 != 0) {
            base64WithPadding += "=";
        }

        // Decode base64 to bytes
        byte[] bytes = Base64.getDecoder().decode(base64WithPadding);

        // Convert bytes to most and least significant bits of UUID
        ByteBuffer byteBuffer = ByteBuffer.wrap(bytes);
        long mostSigBits = byteBuffer.getLong();
        long leastSigBits = byteBuffer.getLong();

        // Return the UUID
        return new UUID(mostSigBits, leastSigBits);
    }

    public static void main(String[] args) {
        // Generate a random UUID
        UUID uuid = UUID.randomUUID();
        System.out.println("Original UUID: " + uuid);

        // Convert to base64
        String base64UUID = uuidToBase64(uuid);
        System.out.println("Base64 UUID (without padding): " + base64UUID);

        // Convert back from base64 to UUID
        UUID decodedUUID = base64ToUUID(base64UUID);
        System.out.println("Decoded UUID: " + decodedUUID);

        // Display the decoded UUID in hexadecimal form
        String hexUUID = decodedUUID.toString().replace("-", "");
        System.out.println("UUID in Hexadecimal: " + hexUUID);
    }
}