Utility class to findout Message Digest checksum for downloded file.

hi,

lot of time after downloading/uploading some file we required some utility to verify integrity of file. This class will be useful for that times. You can generate Message Digest checksum for different algorithem. eg. MD5,SHA1 etc.

package com.blogspot.pravingole;


import java.io.FileInputStream;
import java.security.MessageDigest;
 
public class TestCheckSum {
 
  public static void main(String args[]) throws Exception {
 
    String datafile = "D:/baretailpro.exe"; 
 /*
  * Supported Algorithms are 
  * 
  * MD2,MD5,SHA1,SHA256,SHA384,SHA512
  * 
  */
    MessageDigest md = MessageDigest.getInstance("SHA1");
    FileInputStream fis = new FileInputStream(datafile);
    byte[] dataBytes = new byte[1024];
 
    int nread = 0; 
 
    while ((nread = fis.read(dataBytes)) != -1) {
      md.update(dataBytes, 0, nread);
    };
 
    byte[] mdbytes = md.digest();
 
    //convert the byte to hex format
    StringBuffer sb = new StringBuffer("");
    for (int i = 0; i < mdbytes.length; i++) {
     sb.append(Integer.toString((mdbytes[i] & 0xff) + 0x100, 16).substring(1));
    }
 
    System.out.println("Digest(in hex format):: " + sb.toString());
 
  }
}