B4J Question Hash on nonce

import android.text.TextUtils;

Sub Process_Globals
    Private fx As JFX
    Private MainForm As Form
    Dim nativeMe As JavaObject
End Sub

Sub AppStart (Form1 As Form, Args() As String)  
    nativeMe = Me
    Dim stringToConvert As String
    stringToConvert = "This is a Security Util"

    Dim logstring As String

    logstring = nativeMe.RunMethod("getMD5",Array(stringToConvert))
    Log(logstring)
  
    logstring = nativeMe.RunMethod("getSHA1",Array(stringToConvert))
    Log(logstring)

End Sub

'Return true to allow the default exceptions handler to handle the uncaught exception.
Sub Application_Error (Error As Exception, StackTrace As String) As Boolean
    Return True
End Sub

#If Java

import java.security.MessageDigest;
import java.util.Locale;

    public static String getMD5(String text) {
        String md5 = null;
        if (text=="") {
            return md5;
        }
        MessageDigest md5Digest = null;
        try {
            md5Digest = MessageDigest.getInstance("MD5");
        } catch (Exception e) {
            e.printStackTrace();
            return md5;
        }
        char[] charArray = text.toCharArray();
        byte[] byteArray = new byte[charArray.length];

        for (int index = 0; index < charArray.length; index++) {
            byteArray[index] = (byte) charArray[index];
        }

        byte[] md5Bytes = md5Digest.digest(byteArray);
        StringBuffer hexValue = new StringBuffer();

        for (int index = 0; index < md5Bytes.length; index++) {
            int val = ((int) md5Bytes[index]) & 0xff;
            if (val < 16) {
                hexValue.append("0");
            }
            hexValue.append(Integer.toHexString(val));
        }

        md5 = hexValue.toString();
        return md5;
    }

    public static String bytes2Hex(byte[] bytes) {
        String hs = "";
        String stmp = "";
        for (int n = 0; n < bytes.length; n++) {
            stmp = (Integer.toHexString(bytes[n] & 0XFF));
            if (stmp.length() == 1) {
                hs += "0" + stmp;
            } else {
                hs += stmp;
            }
        }
        return hs.toLowerCase(Locale.ENGLISH);
    }

    public static String getSHA1(String text) {
        String sha1 = null;
        if (text=="") {
            return sha1;
        }
        MessageDigest sha1Digest = null;
        try {
            sha1Digest = MessageDigest.getInstance("SHA-1");
        } catch (Exception e) {
            return sha1;
        }
        byte[] textBytes = text.getBytes();
        sha1Digest.update(textBytes, 0, text.length());
        byte[] sha1hash = sha1Digest.digest();
        return bytes2Hex(sha1hash);
    }
#End If

Sub GetSha1( Text As String) As String
    'Libs:
    'ByteConverter 1.10
    'Encryption    1.10    (from B4A, works with B4J)
    'https://www.b4x.com/android/forum/threads/base64-and-encryption-library.6839/#content

    Dim md As MessageDigest
    Dim ByteCon As ByteConverter

    Dim passwordhash() As Byte
    passwordhash = md.GetMessageDigest( Text.GetBytes("UTF8"), "SHA1")

    Dim sha1string As String
    sha1string = ByteCon.HexFromBytes( passwordhash)

    Return sha1string
End Sub

'Encryption    1.10    (from B4A, works with B4J)