Java Utililty Methods Key Create

StringBuffer uid = new StringBuffer(32);
long currentTimeMillis = System.currentTimeMillis();
uid.append(toHex((int) (currentTimeMillis & -1L), 8));
uid.append(midValueStatic);
uid.append(toHex(System.identityHashCode(new Date()), 8));
uid.append(toHex(getRandom(), 8));
return uid.toString();

byte[] bytes = hexStringToByteArray(keyString);
DESKeySpec keySpec = new DESKeySpec(bytes);
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(ALGORITHM);
SecretKey key = keyFactory.generateSecret(keySpec);
return key;

try {
    byte[] bytes = getBytes(keyString);
    DESKeySpec pass = new DESKeySpec(bytes);
    SecretKeyFactory skf = SecretKeyFactory.getInstance("DES");
    SecretKey s = skf.generateSecret(pass);
    return s;
} catch (Exception e) {
    e.printStackTrace();
...

try {
    SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
    KeySpec spec = new PBEKeySpec(password.toCharArray(), salt.getBytes(), 1000, 256);
    SecretKey tmp = factory.generateSecret(spec);
    return new SecretKeySpec(tmp.getEncoded(), "AES");
} catch (NoSuchAlgorithmException | InvalidKeySpecException e) {
    throw new IllegalStateException("cannot create key: " + e.getMessage(), e);

try {
    byte[] key = siteSecret.getBytes("UTF-8");
    key = Arrays.copyOf(MessageDigest.getInstance("SHA").digest(key), 16);
    return new SecretKeySpec(key, "AES");
} catch (NoSuchAlgorithmException | UnsupportedEncodingException e) {
    e.printStackTrace();
return null;
...

try {
    MessageDigest md5 = MessageDigest.getInstance("MD5");
    md5.update(strSrc.getBytes("UTF8"));
    String result = "";
    byte[] temp;
    temp = md5.digest(key.getBytes("UTF8"));
    for (int i = 0; i < temp.length; i++) {
        result += Integer.toHexString((0x000000ff & temp[i]) | 0xffffff00).substring(6);
...

try {
    return Cipher.getInstance(getKeyExchangeCiperName());
} catch (NoSuchAlgorithmException ex) {
    return null;
} catch (NoSuchPaddingException ex) {
    return null;

KeyFactory keyFactory = null;
try {
    keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
} catch (NoSuchAlgorithmException nsae) {
return keyFactory;

KeyFactory keyFactory = KeyFactory.getInstance("RSA");
return keyFactory;

return KeyFactory.getInstance(ALGORITHM_SIGNATURE);