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Thread: MD5 hash and MimeMessage problem

  1. #1
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    Default MD5 hash and MimeMessage problem

    Hello to all!I m new to forum so excuse me for any mistakes!!Iwan't to get MD5 hash from MimeMessage type!I use the following code to take MD5 :
    //MD5
          private static String convertToHex(byte[] data) {
            StringBuilder buf = new StringBuilder();
            for (int i = 0; i < data.length; i++) {
                int halfbyte = (data[i] >>> 4) & 0x0F;
                int two_halfs = 0;
                do {
                    if ((0 <= halfbyte) && (halfbyte <= 9))
                        buf.append((char) ('0' + halfbyte));
                    else
                        buf.append((char) ('a' + (halfbyte - 10)));
                    halfbyte = data[i] & 0x0F;
                } while(two_halfs++ < 1);
            }
            return buf.toString();
        }
     
     
           private static  String MD5(String text)    {
            MessageDigest md;
            md = MessageDigest.getInstance("MD5");
            byte[] md5hash = new byte[32];
            md.update(text.getBytes("iso-8859-1"), 0, text.length());
            md5hash = md.digest();
            return convertToHex(md5hash);

    As you understand i have to convert MimeMessage into String!My problem is when MimeMessage is type Multipart every time I close my programm the next time it gives me a different MD5 hash!!!But when MimeMessage is NOT Multipart it gives me always the same MD5 hash.The code i use to convert MimeMessage to String is the following:

    //This iis an example code
    MimeMessage message;
    String temp;
     
    //i use it like this
    temp=parseISToString(message.getInputStream());
     
     //Input stream to a string
        public static String parseISToString(java.io.InputStream is){
            java.io.DataInputStream din = new java.io.DataInputStream(is);
            StringBuilder sb = new StringBuilder();
            try{
            String line = null;
            while((line=din.readLine()) != null){
                    sb.append(line).append("\n");
            }
            }catch(Exception ex){
                ex.getMessage();
                }finally{
            try{
                    is.close();
            }catch(Exception ex){}
            }
            return sb.toString();
        }

    I would be grateful if someone gave a solution to this or give me a new way to compute MD5 hash from a MimeMessage type!!Thank you...


  2. #2
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    Default Re: MD5 hash and MimeMessage problem

    try this. hope it helps...

        public String toMD5Hash(String str) throws NoSuchAlgorithmException{
           MessageDigest md = MessageDigest.getInstance("MD5");
           md.update(str.getBytes()); 
           byte[] mdbytes = md.digest();
     
           //convert the byte to hex format method 1
           StringBuffer sb = new StringBuffer();
           for (int i = 0; i < mdbytes.length; i++) {
             sb.append(Integer.toString((mdbytes[i] & 0xff) + 0x100, 16).substring(1));
           }
     
           return sb.toString();
        }

  3. #3
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    Default Re: MD5 hash and MimeMessage problem

    Thank you for your answer and happy new year!!I've tried your code but i have the same results!!So i think the poblem is not with the code of MD5 but with the input String i give...The code i use to turn the MimeMessage into String is :

    //This iis an example code
    MimeMessage message;
    String temp;
     
    //I use method .getInputString an then i convert InputString into a String with parseISToString
    //Thats how i get the String for the MD5 
     
    temp=parseISToString(message.getInputStream());
     
     //Input stream to a string
        public static String parseISToString(java.io.InputStream is){
            java.io.DataInputStream din = new java.io.DataInputStream(is);
            StringBuilder sb = new StringBuilder();
            try{
            String line = null;
            while((line=din.readLine()) != null){
                    sb.append(line).append("\n");
            }
            }catch(Exception ex){
                ex.getMessage();
                }finally{
            try{
                    is.close();
            }catch(Exception ex){}
            }
            return sb.toString();
        }

    Somehow Multipart MimeMessage gives different String every time i close and reopen the program!!!Has anybody an idea why this happenning?? Thank you in advance!!

  4. #4
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    Default Re: MD5 hash and MimeMessage problem

    I found the problem!This is how you turn a MimeMessage to a String :

               int size;
               InputStream temp1 = null;
               String temp = new String();
                byte[] b;
               String value;
     
     
     
                size=message.getSize();
                temp1=message.getInputStream();
                b=new byte[size];
                temp1.read(b,0,size);
                value=new String(b);

    The value is the String you put in MD5(value) !!!!

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