Security comments, am I on track? Encryption using AES

Question

I have implemented a crypto, but I cant say that I fully understand every step and hence not how secure it is/isnt.
One thing I noticed was if I generated keys with a length other than 128/192/256 I got Exception in thread "main" java.security.InvalidKeyException: Key length not 128/192/256 bits
I also wonder about the ivBytes, should I generate them in some specific way?
Any other comments are also very appreciated.
I genereate a key like this    SecureRandom     random = new SecureRandom();
    javax.crypto.KeyGenerator generator = KeyGenerator.getInstance("AES", "BC");
    generator.init(256, random);
    Key encryptionKey = generator.generateKey();
//Save to fileEncode like this
byte[]        input = "SOME SECRET OF MINE".getBytes();
    //Read key from file
    byte[]          ivBytes = new byte[] {
      0x00, 0x00, 0x00, 0x01, 0x04, 0x05, 0x06, 0x07,
      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01 };
    Cipher          cipher = Cipher.getInstance("AES/CTS/NoPadding", "BC");
       cipher.init(Cipher.ENCRYPT_MODE, encryptionKey,
      new IvParameterSpec(ivBytes));
    byte[] cipherText = new byte[cipher.getOutputSize(input.length)];
    int ctLength = cipher.update(input, 0, input.length, cipherText, 0);
    ctLength += cipher.doFinal(cipherText, ctLength);
//Save ciphertext to fileDecode like this
byte[]          ivBytes = new byte[] {
      0x00, 0x00, 0x00, 0x01, 0x04, 0x05, 0x06, 0x07,
      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01 };
    //Read cipher from file
    //Read key from file
    Cipher          cipher = Cipher.getInstance("AES/CTS/NoPadding", "BC");
    cipher.init(Cipher.DECRYPT_MODE, decryptionKey,
      new IvParameterSpec(ivBytes));
    byte[] cipherBytes = Utils.fromHex(cipherText);
    byte[] plainText = new byte[cipher.getOutputSize(cipherBytes.length)];
    int ptLength = cipher.update(cipherBytes, 0, cipherBytes.length, plainText, 0);
    ptLength += cipher.doFinal(plainText, ptLength);
                                 System.out.println(ptLength);
    System.out.println("Hidden was:" + Utils.toString(plainText));

Answer 1

No.
I will repeat one of Tom Kytes' mantras here
1 when you can do it in 1 SQL statement, you should do it in SQL
2 When you can not do it in SQL, you should do it in PL/SQL
3 When you can not do in in PL/SQL, you should do it in Java
Which means: You should things non-procedurally as often as possible. Quite often people resort too early to 3GL strategies.
update inside a loop raises a red flag, especially if there would have been a commit inside this loop. This means you are not only into slow-by-slow prtogramming, but also increases the possibility of ora-15555 errors.
Sybrand Bakker
Senior Oracle DBA