Md5 checksum in 9.2

Question

Hi,
I am generating some output for client in 9.2 database and sending this output file to client. Client want md5 checksum for whole file to be get added in a header of output file. In Oracle 9.2 is it possbile to get md5 value for complete query output ?
( I know it is not easy, may be store output as CLOB and then calculate md5 value ...etc ).
This question is for my learning.
thanks & regards
pjp

Answer 1

Here are a couple of methods you can use...
public static String md5(byte[] buffer) {
     StringBuffer md5Hash = new StringBuffer(32);
     try {
          byte[] b = java.security.MessageDigest.getInstance("MD5").digest(buffer);
          int len = b.length;
          for (int x=0; x<len; x++) {
               md5Hash.append(String.format("%02x",b[x]));
     catch (java.security.NoSuchAlgorithmException e) {
          e.printStackTrace();
     return(md5Hash.toString());
public static String md5File(String file) {
     String md5Hash = "";
     try {
          FileInputStream in = new FileInputStream(file);
          int bytes = in.available();
          byte[] buffer = new byte[bytes];
          in.read(buffer);
          in.close();
          md5Hash = md5(buffer);
     catch (Exception e) {
          e.printStackTrace();
     return md5Hash;
}