import java.io.*;

public class CopyBytes {
  public static void main(String[] args) throws IOException {

    String filename = "lena.png";

    try (FileInputStream in = new FileInputStream(filename);
      FileOutputStream out = new FileOutputStream("__"+filename)) {
      
      byte []array = new byte[512];
      int length;

      while ((length = in.read(array)) != -1) {
        System.out.println(length);
        out.write(array, 0, length);
      }
    } 
  }
}