how to solve InvalidKeyException problem?

Question

I encrypt my AES random key using RSA algorithm and public key, then I convert encoded bytes into secret key to encrypt my file, but an error occurred: Exception in thread "main" java.security.InvalidKeyException: Invalid AES key length: 256 bytes

this is my public key code:

public class keyGenerator {

KeyPairGenerator generator = KeyPairGenerator.getInstance("RSA");
KeyPair pair = generator.generateKeyPair();
PrivateKey privateKey = pair.getPrivate();
PublicKey publicKey = pair.getPublic();

public keyGenerator() throws NoSuchAlgorithmException, FileNotFoundException, IOException, InvalidKeySpecException {
    generator.initialize(2048);
    try ( FileOutputStream fos = new FileOutputStream("private.key")) {
        fos.write(privateKey.getEncoded());
    }
}

}

and this is my AESEncryption method (NOTICE THAT cipherTxt.init(Cipher.ENCRYPT_MODE, sk); occurred the problem):

 public static void AESEncryption(File in, File out) throws FileNotFoundException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException, IllegalArgumentException, IOException, InvalidKeySpecException, GeneralSecurityException {
    try {
        //create GenerateKey object to accsess publicKey
        private int KEY_SIZE = 128;
        keyGenerator Key = new keyGenerator();
        PublicKey pk = Key.publicKey;
        //create random key
        KeyGenerator g = KeyGenerator.getInstance("AES");
        //give it size
        g.init(KEY_SIZE);
        //assign g.generateKey() to secretKey Randomkey
        Randomkey = g.generateKey();
        // encrypt the random key with RSA and public key
        byte[] RandomByteKey = Randomkey.getEncoded();
        Cipher cipherKey = Cipher.getInstance("RSA");
        cipherKey.init(Cipher.ENCRYPT_MODE, pk);
        byte[] encryptedKey = cipherKey.doFinal(RandomByteKey);//RSA key
        SecretKey sk = new SecretKeySpec(encryptedKey, 0, encryptedKey.length, "AES");
        //after generating RSA key we will Encrypt file using RSA key
        Cipher cipherTxt = Cipher.getInstance("AES");
        cipherTxt.init(Cipher.ENCRYPT_MODE, sk);
        byte[] message = Files.readAllBytes(in.toPath());
        byte[] encryptedMessage = cipherTxt.doFinal(message);
        out.createNewFile();
        Files.write(out.toPath(), encryptedKey);
        Files.write(out.toPath(), encryptedMessage, StandardOpenOption.APPEND);
        BufferedReader br = new BufferedReader(new FileReader("bla.bin"));
        String line1;
        while ((line1 = br.readLine()) != null) {
            System.out.println(line1);
        }
    } catch (NoSuchAlgorithmException | NoSuchPaddingException | IllegalBlockSizeException e) {
        throw new RuntimeException("RSA or AES/GCM not available", e);
    } catch (BadPaddingException e) {
        throw new RuntimeException("Padding failed for NoPadding", e);
    }

}

what should I do?