Convert MD5 into String in java

Can anyone know how to convert the MD5 to String. In my case I have saved the password in MD5 in database. I am trying to retreive the password and display it in string for the editing purpose.

This is what I have done for converting the string into encrypt format:

public static String encrypt(String source) {
   String md5 = null;
   try {
         MessageDigest mdEnc = MessageDigest.getInstance("MD5"); //Encryption algorithm
         mdEnc.update(source.getBytes(), 0, source.length());
         md5 = new BigInteger(1, mdEnc.digest()).toString(16); // Encrypted string
        } 
    catch (Exception ex) {
         return null;
    }
    return md5;
}

I don't know how convert the encrypt format into string for editing the password.