import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.security.DigestInputStream;
import java.security.MessageDigest;
import java.util.Formatter;

public class HashFunctionTest {

public static String calculateHash(MessageDigest algorithm,
String fileName) throws Exception{

FileInputStream fis = new FileInputStream(fileName);
BufferedInputStream bis = new BufferedInputStream(fis);
DigestInputStream dis = new DigestInputStream(bis, algorithm);

// read the file and update the hash calculation
while (dis.read() != -1);

// get the hash value as byte array
byte[] hash = algorithm.digest();

return byteArray2Hex(hash);
}

private static String byteArray2Hex(byte[] hash) {
Formatter formatter = new Formatter();
for (byte b : hash) {
formatter.format(”%02x”, b);
}
return formatter.toString();
}

public static void main(String[] args) throws Exception {
String fileName = “javablogging.png”;

MessageDigest sha1 = MessageDigest.getInstance(”SHA1″);
MessageDigest md5 = MessageDigest.getInstance(”MD5″);

System.out.println(calculateHash(sha1, fileName));
System.out.println(calculateHash(md5, fileName));
}
}

gracias.. lo necesito con urgencia