import java.io.*;

public class M {

public static void main(String[] args) throws FileNotFoundException {

StopWatch stopWatch = new StopWatch();
 int bufferSize = 8192;

 String filename1 = "/Users/paul/Downloads/star1.zip";
 FileInputStream fileInputStream = new FileInputStream(new File(filename1));
 FileOutputStream fileOutputStream = new FileOutputStream(new File(filename1 + ".copy"));

 String filename3 = "/Users/paul/Downloads/star2.zip";
 BufferedInputStream bufferedInputStream = new BufferedInputStream(new FileInputStream(new File(filename3)), bufferSize);
 BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(new FileOutputStream(new File(filename3 + ".copy")));

 // 실제론 왜 이게 더 빠름?
 byte[] buffer = new byte[bufferSize];
 try {
stopWatch.start();

 while (true) {
if (fileInputStream.read(buffer) == -1) break;
 fileOutputStream.write(buffer);
 }
fileInputStream.close();
 fileInputStream.close();

 stopWatch.stop();
 System.out.println(stopWatch);
 } catch(IOException e) {}

// 이게 더 빠르다며
 try {
stopWatch.start();

 int data;
 int readCount = 0;
 byte[] buf = new byte[bufferSize];
 while (true) {
// data = bufferedInputStream.read(); 이렇게 하면 bufferedInputStream이 훨씬 느리
 data = bufferedInputStream.read(buf, 0, buf.length); // 이렇게 하면 둘다 속도 동일함
 if (data == -1) break;
// bufferedOutputStream.write(data);
 bufferedOutputStream.write(buf);
 readCount++;
 }
bufferedInputStream.close();
 bufferedOutputStream.close();

 stopWatch.stop();
 System.out.println(stopWatch);

 System.out.println(readCount);
 } catch (IOException e) {}


}
}

class StopWatch {
private long start;
 private long end;

 public void start() {
start = System.currentTimeMillis();
 }

public void stop() {
end = System.currentTimeMillis();
 }

public long getTime() {
return end - start;
 }

public String toString() {
return String.valueOf(getTime());
 }
}