文件下载servelt,乱码，取不到文件大小

文件下载servelt,乱码，取不到文件大小

public void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
   String   filename="测试";
   String client = request.getHeader("user-agent").toLowerCase();
   System.out.println(client);
   if (client.indexOf("msie") >= 0) {
    filename = java.net.URLEncoder.encode(filename, "utf-8");
    filename = javax.mail.internet.MimeUtility.encodeText(filename,"utf-8","B");
   } else {
    filename = javax.mail.internet.MimeUtility.encodeText(filename,"utf-8","B");
   }
   response.setContentType("APPLICATION/OCTET-STREAM");
   response.addHeader("Content-Disposition", "attachment; filename="+filename+".exe");
   OutputStream os = response.getOutputStream();
   File f = new File ("C:/Downloads/MyEclipse_5.5M2_E3.2.2_Installer.exe");
   FileInputStream isf = new FileInputStream(f);
   InputStreamReader isr = new InputStreamReader(isf);
   BufferedReader rb = new BufferedReader(isr);
   byte[] b = new byte[10240];
   int i = 0;
   while (isf.read(b) != -1) {
//    os.write(b);
   }
   for (int x = 0; x < 100000; x++) {
    os.write(("enum"+x+",\r\n").getBytes());
   }
   os.close();
}

</script>