package tsdemo;
/*
 * amHashFile.java
 *
 * Created on 2007. March 22
 *
 */

import java.security.MessageDigest;

import java.io.InputStream;

import oracle.sql.BLOB;

public class amHashFile 
{   
    /** Creates a new instance of HashFile */
    public amHashFile() {
    }
    
    public static byte[] getHash(oracle.sql.BLOB blobFile, String Algorithm) {
        try {
            MessageDigest d = MessageDigest.getInstance(Algorithm);     // Get a hash handler
            //FileInputStream f = new FileInputStream(Filename);          // open file for hashing
            /* get the blob from the documents table as a binary input stream */
            //oracle.sql.BLOB blob = blobFile;
            InputStream f = blobFile.getBinaryStream ();
            //
            byte[] b = new byte[1];                                     
            while ( -1 != f.read(b, 0, 1))                              // feed the message digester
                d.update(b);
            f.close();
            return d.digest();                                          // get the final hash and return it
        } catch (Exception e) {
        System.out.println("Hashing Error " + e.getMessage());
            return null;
        }
    }
    
}