Creating cipher key from random text on Android

Question

I'm having a little problem. In my app I need to create a key for AES encryption from String written by a user, and I have no idea how to do it. For example: user writes: "abscde" and I need to some how change it to an AES key. Here is my code. It works but only with key provided in hex, like "000102030405060708090A0B0C0D0E0F".

   public static String encrypt(String text, String key){
        String mess="error";
        try{

            byte[] encodedText=text.getBytes(Charset.forName("UTF-8"));
            byte[] keyData=hexStringToByte(key);

            SecretKeySpec sKey=new SecretKeySpec(keyData, "AES");

            Cipher encryptionCypher=Cipher.getInstance("AES/CBC/PKCS5Padding");

            final int blocks=encryptionCypher.getBlockSize();

            final byte[] ivData=new byte[blocks];

            final SecureRandom rnd=new SecureRandom();

            rnd.nextBytes(ivData);

            final IvParameterSpec iv=new IvParameterSpec(ivData);
            encryptionCypher.init(Cipher.ENCRYPT_MODE, sKey,iv);

            final byte[] encryptedMessage=encryptionCypher.doFinal(encodedText);
            final byte[] ivAndMessage=new byte[ivData.length+encryptedMessage.length];
            System.arraycopy(ivData, 0, ivAndMessage, 0, blocks);
            System.arraycopy(encryptedMessage, 0, ivAndMessage, blocks, encryptedMessage.length);
            final String finalMessage=Base64.encodeToString(ivAndMessage, 0);

            mess=finalMessage;  


            } catch (IllegalBlockSizeException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (BadPaddingException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (InvalidKeyException e) {
                e.printStackTrace();

            } catch (InvalidAlgorithmParameterException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (NoSuchAlgorithmException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (NoSuchPaddingException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        return mess;
    }