import java.io.FileInputStream;
import java.io.ObjectInputStream;
import java.security.DigestInputStream;
import java.security.MessageDigest;
public class Main {
public static void main(String args[]) throws Exception {
FileInputStream fis = new FileInputStream("test");
MessageDigest md = MessageDigest.getInstance("SHA");
DigestInputStream dis = new DigestInputStream(fis, md);
ObjectInputStream ois = new ObjectInputStream(dis);
Object o = ois.readObject();
if (!(o instanceof String)) {
System.out.println("Unexpected data in file");
System.exit(-1);
}
String data = (String) o;
System.out.println("Got message " + data);
dis.on(false);
o = ois.readObject();
if (!(o instanceof byte[])) {
System.out.println("Unexpected data in file");
System.exit(-1);
}
byte origDigest[] = (byte[]) o;
System.out.println(MessageDigest.isEqual(md.digest(), origDigest));
}
}