code: @Deprecated
      public static synchronized String hash(String data) {
          return org.jivesoftware.smack.util.SHA1.hex(data);
      }
docs: Hashes a String using the SHA-1 algorithm and returns the result as a
  String of hexadecimal numbers. This method is synchronized to avoid
  excessive MessageDigest object creation. If calling this method becomes
  a bottleneck in your code, you may wish to maintain a pool of
  MessageDigest objects instead of using this method.
  <p>
  A hash is a one-way function -- that is, given an
  input, an output is easily computed. However, given the output, the
  input is almost impossible to compute. This is useful for passwords
  since we can store the hash and a hacker will then have a very hard time
  determining the original password.
  
  @param data the String to compute the hash of.
  @return a hashed version of the passed-in String
  @deprecated use {@link org.jivesoftware.smack.util.SHA1#hex(String)} instead.