Re: Problem to download a file from 2 browsers at the time

From:
KiLVaiDeN <kilvaiden@free.fr>
Newsgroups:
comp.lang.java.help
Date:
Wed, 21 Jun 2006 01:19:47 +0200
Message-ID:
<44988247$0$1602$636a55ce@news.free.fr>
prado wrote:

I have this JSP that download an excel file.

It works fine if I use only one browser at the same time.

The problem is when I try to do this but from 2 browsers at the same
time. From each browser I can download a part of the file but not the
complete file.
It seems the browsers are sharing the bandwidth and when it starts to
download a file the other stops.

I have look the logs, and I saw the file has downloaded to the computer

and while the the jsp is working.
I don't undestand why the file has finished to download and while the
jsp is still executing.

Can you help me please?

do anybody try this JSP and tell me if the result is the same as me?

------------------------------------------JSP
-----------------------------------------------------------------------------------

<%@page contentType="application/vnd.ms-excel"%>

<%@ page language="java" import="java.io.*"%>
<%@ page language="java" import="java.util.*"%>

<%

Date fecha = new Date();

java.sql.Date fechaSQL = new java.sql.Date(fecha.getTime());

Calendar calendario = Calendar.getInstance();
calendario.setTime(fecha); // fecha es el Date de antes.
String strHour = String.valueOf( calendario.get(Calendar.HOUR) );
String strMinute = String.valueOf( calendario.get(Calendar.MINUTE) );
String strSecond = String.valueOf( calendario.get(Calendar.SECOND) );

String nombre = "FILE" + strHour + strMinute + strSecond + ".xls";

 System.out.println( " IN OF " + nombre );

     response.setContentType( "application/x-download" );

     response.setHeader("Content-type","application/vnd.ms-excel");

     response.setHeader("Content-Disposition","attachment; filename=\""
+ nombre + "\"");

 System.out.println( nombre + " START" );

for (int l=0;l<30000;l++){
 System.out.println( nombre + " " + l );

  for (int k=0;k<250;k++){

        out.write(nombre + " : ("+ l + "," + k + ")" + "\t" );

  }
        out.write("\n");

}

 System.out.println( nombre + " END" );

%>


Hi,

I think it's much more efficient to implement the file downloading
mechanism in a Servlet, I don't think it's a good idea to put that kind
of code in a JSP.

Then, I'm wondering about that code you posted. Is it really generating
a valid XLS file ? And where is your "download" script ?

I'd advice you to read this tutorial :
http://www.onjava.com/pub/a/onjava/excerpt/jebp_3/index1.html?page=1

I think it'll give you a good hint on how to make your download Servlet.

K

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