import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.security.DigestInputStream;
import java.security.MessageDigest;
public class MainClass {
private static int BUFFER_SIZE = 32 * 1024;
public static void main(String[] args) throws Exception {
System.out.println("test.txt: " + md("test.txt"));
}
public static String md(String f) throws Exception {
BufferedInputStream file = new BufferedInputStream(new FileInputStream(f));
MessageDigest md = MessageDigest.getInstance("SHA-1");
DigestInputStream in = new DigestInputStream(file, md);
int i;
byte[] buffer = new byte[BUFFER_SIZE];
do {
i = in.read(buffer, 0, BUFFER_SIZE);
} while (i == BUFFER_SIZE);
md = in.getMessageDigest();
in.close();
return new String(md.digest());
}
}