testhash.java

a Big Java source Code Exemples

// Updates: 2004.03.24


import java.security.*;
import java.math.*;
import java.io.*;


/** 
 * Permet de faire un hash (SHA ou MD5) d'un fichier fourni en param鑤re.
 */
public class TestHash {
  final static String ALGO = "SHA";  // SHA or MD5
  
  
  public static void main(String[] args) {
    try {
      byte[] data = readFile(args[0]);
      MessageDigest md = MessageDigest.getInstance(ALGO);
      md.update(data);
      byte[] digest = md.digest();
      System.out.println("Algo: " + ALGO + " (" + digest.length + " bytes)");
      for (int i = 0; i < digest.length; i++) {
        System.out.print(digest[i] + " ");
      }
      System.out.println("\nDecimal: " + new BigInteger(digest));
      System.out.println("Hexadecimal: " + new BigInteger(digest).toString(16));
    }
    catch (Exception e) {
      System.out.println(e);  
    }    
  }
  
  
  private static byte[] readFile(String filename) {
    try {
      RandomAccessFile raf = new RandomAccessFile(filename, "r");
      byte[] data = new byte[(int)raf.length()];
      raf.readFully(data);
      raf.close();
      return data;
    }
    catch (FileNotFoundException e) {}
    catch (IOException e) {}
    return null;
  }  
}