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ServletOutputStream is not working?

Maruli Lee

Joined: Dec 09, 2004
Posts: 11
I had a previous program which is working fine so I just copied the chunk of code and paste it on the new program which I am building. Basically my program will generate a report using JExcel API and then I will try to display it on the web so that user can Open/Save/Cancel it (the normal IE notification window). Furthermore, there is no error message on the tomcat log.

[ November 27, 2007: Message edited by: Maruli Lee ]
[ November 27, 2007: Message edited by: Bear Bibeault ]
Ben Souther

Joined: Dec 11, 2004
Posts: 13410

Is this code in a servlet or a JSP?

Java API J2EE API Servlet Spec JSP Spec How to ask a question... Simple Servlet Examples jsonf
Maruli Lee

Joined: Dec 09, 2004
Posts: 11
Hi Ben,

It's in JSP, that's why I posted it under the JSP forum.

Additional info, this chunck of codes are embedded within

<form name="frm" method="POST">
//Code goes here
[ November 27, 2007: Message edited by: Maruli Lee ]
Bear Bibeault
Author and ninkuma

Joined: Jan 10, 2002
Posts: 61973

So you are embedding the output in the middle of some HTML? Of course that won't work. What are you really trying to do?

[Asking smart questions] [Bear's FrontMan] [About Bear] [Books by Bear]
Maruli Lee

Joined: Dec 09, 2004
Posts: 11
No no no. The codes are within the JSP tags <% %>

Actually my JSP will be calling a Java program which will generate a report in Excel (Using JExcel API). After the report is created it will be stored in C:\tomcat\webapps\SnetReport\REPORT

What I am trying to do is to pop up a save file dialog box so that the user can retrieve the file from the web instead of having to go into the folder to get it manually.
Ulf Dittmer

Joined: Mar 22, 2005
Posts: 42952
A good rule of thumb is to not use the servlet output stream in a JSP, ever. As Bear said, it won't work. Theoretically, it might, but practically, it won't. Moving the code into a servlet will help.
William Brogden
Author and all-around good cowpoke

Joined: Mar 22, 2000
Posts: 12868

Of course it won't - JSP has automagically already gotten the output stream for character output - thats what JSP do. You are undoubtedly getting a thrown at that point. See the JavaDocs.

Maruli Lee

Joined: Dec 09, 2004
Posts: 11
I have modified my code to avoid using OutputStream since it will cause a lot of problem. Now my modified code looks like this:

After I ran through this code my JSP page will refresh and show me this screen:

In addition, Tomcat shows following message:

Nov 29, 2007 10:44:38 AM org.apache.jasper.runtime.PageContextImpl release
WARNING: Internal error flushing the buffer in release()
Stefan Evans

Joined: Jul 06, 2005
Posts: 1085
As has been mentioned, JSPs are designed for output of text.
Sending a binary file via JSP is tricky for a number of reasons.

I would recommend you read Bear's excellent article on this subject: The Secret Life of JavaServer Pages where he answers the question "Why does everyone tell me to use a servlet to send binary data to the browser? I wanna use a JSP!"

You've written it all in java code anyway - it SHOULD be a servlet.
I agree. Here's the link:
subject: ServletOutputStream is not working?