import java.io.*;

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

    String filename = "lena.png";

    try (BufferedInputStream in = new BufferedInputStream(new FileInputStream(filename));
      BufferedOutputStream out = new BufferedOutputStream(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);
      }
    } 
  }
}