Low speed downloading when uses URL class.

Question

In normal downloading(such as "right click -> save as" in ie), my connection speed can reach up to 1.8MBytes/s, but when I use URL to download a file, the speed is obviously lower than the normal one, each read procedure gets 4KBytes ~ 5KBytes
pseudo code here:
URL url = new URL("...");
URLConnection conn = url.openConnection();
conn.connect();
BufferedInputStream bis = new BufferedInputStream(conn.getInputStream(), 1024*1024);
while ((len = bis.read(buf, 0, buf.length)) > 0) {
System.out.println(len);
}

Answer 1

sorry for my mistake.
the above pseudo code is the logical outline of my method, here is my code, thx for helping me :)
     public void doDownload() {
          System.out.println("Download started...");
          try {
               URL url = new URL(vdLink);
               URLConnection connection = url.openConnection();
               int len, sum = 0;
               byte[] buf = new byte[DOWNLOAD_BUFFER_SIZE];
               connection.connect();
               System.out.println("File size: " + connection.getContentLength() + " bytes.");
               BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream( appDir + downloadDir + "\\" + vdFileName), DOWNLOAD_BUFFER_SIZE);
               BufferedInputStream bis = new BufferedInputStream(connection.getInputStream(), DOWNLOAD_BUFFER_SIZE);
               while ((len = bis.read(buf, 0, buf.length)) > 0) {
                    bos.write(buf, 0, len);
                    sum += len;
                    System.out.println(len/1024 + " Kbytes has been downloaded.");
               bis.close();
               bos.close();
          }catch (MalformedURLException urlExcept) {
               urlExcept.printStackTrace();
          }catch (IOException ioe) {
               ioe.printStackTrace();
          System.out.println("Download finished.");
     }