Re: Output PDF
I'm assuming that your browser client is IE. If so, the reason your
Action is being called twice is because of a feature in IE 4.x+. If
your application returns data that is to be handled with an ActiveX
control (ie Adobe Acrobat Reader) the browser sends additional
requests to the server. In IE 4.x and 5 it actually sends three
requests. For IE 5.5+ it sends two.
Assuming that your using IE 5.5+, the first request is the original
request (duh), but then IE sends a second request to get the
content-type. Who knows why they can't figure this out on the first
request ;) This second request has it's userAgent header set to
contype. You can solve this problem and increase the performance of
your application by writing a Servlet filter that sits in front of
whatever Actions you have setup to serve PDF content. Have this
filter look at the userAgent header of each request. If it's set to
contype just send an an empty response back to the client with the
content type set to application/pdf. Simple as that.
Now, the reason your getting an exception in the second code snippet
you provided is because after you do your forward the JSP calls
response.getOutputStream(). This is done behind the scenes but you
can see it if you look at your generated Servlet code. This method
can only be called once during the lifestyle of the request, hence
your exception.
It's generally a bad idea to have a JSP produce binary content anyway.
They were designed for Text or HTML output.
I wrote a generic/reusable Servlet whose sole purpose in life is to
write binary content back to a client. I called it
BinaryOutputServlet. You put your binary data (byte[]) and the
content type of the data in the request scope and forward to it. It
gets the data and content type out of the request and writes it back
to the client. It can be used for any type of data this way. I would
recommend doing something similar since Actions are really for
control. By writing back to the client from an Action you are
violating the MVC model anyway.
I hope this helps. Oh, and you can read all about the feature of IE here:
http://support.microsoft.com/default.aspx?scid=kb;EN-US;q293792
Virtually,
Andre Van Klaveren, SCP
On Mon, 14 Mar 2005 14:01:48 -0600, Brad Balmer [EMAIL PROTECTED] wrote:
I'm using Jasper to create PDF's through my Actions and cannot figure out a
good way to export the resulting byte[] to the user.
Currently the tail end of my Action class looks like this:
byte[] reportBytes = null;
File jasperReport = new File(location);
try {
reportBytes = JasperRunManager.runReportToPdf(jasperReport.getPath(),
parameters, dataSource);
log.info(Found : + reportBytes.length);
} catch (JRException e) {
e.printStackTrace();
}
response.setContentType(application/pdf);
response.setContentLength(reportBytes.length);
ServletOutputStream ouputStream = response.getOutputStream();
ouputStream.write(reportBytes, 0, reportBytes.length);
ouputStream.flush();
ouputStream.close();
return(null);
This will display the pdf, but the action class itself somehow get called a
second time as the above log statement is displayed twice.
I also tried to set the byte[] on the request and forward onto another page
which does:
%
byte[] reportBytes =
(byte[])request.getAttribute(REPORT_BYTES);
response.setContentType(application/pdf);
response.setContentLength(reportBytes.length);
ServletOutputStream ouputStream = response.getOutputStream();
ouputStream.write(reportBytes, 0, reportBytes.length);
ouputStream.flush();
ouputStream.close();
%
But this complains about: getOutputStream() has already been called for this
response
Any ideas?
--
Virtually,
Andre Van Klaveren
SCP
-
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
Re: Output PDF
Why are you doing that in a jsp? You can do it in an action, but it
will not work that well (but it will work better tahn in a jsp, i
promise).
The other issue is that a URL ending in /foo.do?name=value will not be
seen by IE as a pdf. You should probably use a servlet for this
instead, then you can map the URL like the one above as this:
/foo/name/value/file.pdf, that will trick the browser into thinking
that it is just a static file.
Another problem you will have is that if you are using ssl, IE will
not allow acrobat to read from the cache. Your users will have to hack
the registry to make it work.
Larry
On Mon, 14 Mar 2005 14:01:48 -0600, Brad Balmer [EMAIL PROTECTED] wrote:
I'm using Jasper to create PDF's through my Actions and cannot figure out a
good way to export the resulting byte[] to the user.
Currently the tail end of my Action class looks like this:
byte[] reportBytes = null;
File jasperReport = new File(location);
try {
reportBytes = JasperRunManager.runReportToPdf(jasperReport.getPath(),
parameters, dataSource);
log.info(Found : + reportBytes.length);
} catch (JRException e) {
e.printStackTrace();
}
response.setContentType(application/pdf);
response.setContentLength(reportBytes.length);
ServletOutputStream ouputStream = response.getOutputStream();
ouputStream.write(reportBytes, 0, reportBytes.length);
ouputStream.flush();
ouputStream.close();
return(null);
This will display the pdf, but the action class itself somehow get called a
second time as the above log statement is displayed twice.
I also tried to set the byte[] on the request and forward onto another page
which does:
%
byte[] reportBytes =
(byte[])request.getAttribute(REPORT_BYTES);
response.setContentType(application/pdf);
response.setContentLength(reportBytes.length);
ServletOutputStream ouputStream = response.getOutputStream();
ouputStream.write(reportBytes, 0, reportBytes.length);
ouputStream.flush();
ouputStream.close();
%
But this complains about: getOutputStream() has already been called for this
response
Any ideas?
-
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
RE: Output PDF
Thanks for the great response. This should take care of all my issues.
-Original Message-
From: Andre Van Klaveren [mailto:[EMAIL PROTECTED]
Sent: Monday, March 14, 2005 2:39 PM
To: Struts Users Mailing List; [EMAIL PROTECTED]
Subject: Re: Output PDF
I'm assuming that your browser client is IE. If so, the reason your
Action is being called twice is because of a feature in IE 4.x+. If
your application returns data that is to be handled with an ActiveX
control (ie Adobe Acrobat Reader) the browser sends additional
requests to the server. In IE 4.x and 5 it actually sends three
requests. For IE 5.5+ it sends two.
Assuming that your using IE 5.5+, the first request is the original
request (duh), but then IE sends a second request to get the
content-type. Who knows why they can't figure this out on the first
request ;) This second request has it's userAgent header set to
contype. You can solve this problem and increase the performance of
your application by writing a Servlet filter that sits in front of
whatever Actions you have setup to serve PDF content. Have this
filter look at the userAgent header of each request. If it's set to
contype just send an an empty response back to the client with the
content type set to application/pdf. Simple as that.
Now, the reason your getting an exception in the second code snippet
you provided is because after you do your forward the JSP calls
response.getOutputStream(). This is done behind the scenes but you
can see it if you look at your generated Servlet code. This method
can only be called once during the lifestyle of the request, hence
your exception.
It's generally a bad idea to have a JSP produce binary content anyway.
They were designed for Text or HTML output.
I wrote a generic/reusable Servlet whose sole purpose in life is to
write binary content back to a client. I called it
BinaryOutputServlet. You put your binary data (byte[]) and the
content type of the data in the request scope and forward to it. It
gets the data and content type out of the request and writes it back
to the client. It can be used for any type of data this way. I would
recommend doing something similar since Actions are really for
control. By writing back to the client from an Action you are
violating the MVC model anyway.
I hope this helps. Oh, and you can read all about the feature of IE here:
http://support.microsoft.com/default.aspx?scid=kb;EN-US;q293792
Virtually,
Andre Van Klaveren, SCP
On Mon, 14 Mar 2005 14:01:48 -0600, Brad Balmer [EMAIL PROTECTED] wrote:
I'm using Jasper to create PDF's through my Actions and cannot figure out
a
good way to export the resulting byte[] to the user.
Currently the tail end of my Action class looks like this:
byte[] reportBytes = null;
File jasperReport = new File(location);
try {
reportBytes = JasperRunManager.runReportToPdf(jasperReport.getPath(),
parameters, dataSource);
log.info(Found : + reportBytes.length);
} catch (JRException e) {
e.printStackTrace();
}
response.setContentType(application/pdf);
response.setContentLength(reportBytes.length);
ServletOutputStream ouputStream = response.getOutputStream();
ouputStream.write(reportBytes, 0, reportBytes.length);
ouputStream.flush();
ouputStream.close();
return(null);
This will display the pdf, but the action class itself somehow get called
a
second time as the above log statement is displayed twice.
I also tried to set the byte[] on the request and forward onto another
page
which does:
%
byte[] reportBytes =
(byte[])request.getAttribute(REPORT_BYTES);
response.setContentType(application/pdf);
response.setContentLength(reportBytes.length);
ServletOutputStream ouputStream = response.getOutputStream();
ouputStream.write(reportBytes, 0, reportBytes.length);
ouputStream.flush();
ouputStream.close();
%
But this complains about: getOutputStream() has already been called for
this
response
Any ideas?
--
Virtually,
Andre Van Klaveren
SCP
-
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
Re: Output PDF
Woh! IE *does not* use the URL to determine content type. It's
determined by the MIME type sent back with the response from the
server.
And, by default, the option to have IE save encrypted data to disk is
turned on, so there won't be an issue with PDFs and SSL unless
Micro$oft has changed this is XPSP2. I'm running XPSP2 at home and
have no problem viewing PDFs over an encrypted connection. Micro$oft
would be breaking a lot of clients if they chose to change that
setting.
Virtually,
Andre Van Klaveren, SCP
On Mon, 14 Mar 2005 13:43:51 -0700, Larry Meadors
[EMAIL PROTECTED] wrote:
Why are you doing that in a jsp? You can do it in an action, but it
will not work that well (but it will work better tahn in a jsp, i
promise).
The other issue is that a URL ending in /foo.do?name=value will not be
seen by IE as a pdf. You should probably use a servlet for this
instead, then you can map the URL like the one above as this:
/foo/name/value/file.pdf, that will trick the browser into thinking
that it is just a static file.
Another problem you will have is that if you are using ssl, IE will
not allow acrobat to read from the cache. Your users will have to hack
the registry to make it work.
Larry
On Mon, 14 Mar 2005 14:01:48 -0600, Brad Balmer [EMAIL PROTECTED] wrote:
I'm using Jasper to create PDF's through my Actions and cannot figure out a
good way to export the resulting byte[] to the user.
Currently the tail end of my Action class looks like this:
byte[] reportBytes = null;
File jasperReport = new File(location);
try {
reportBytes = JasperRunManager.runReportToPdf(jasperReport.getPath(),
parameters, dataSource);
log.info(Found : + reportBytes.length);
} catch (JRException e) {
e.printStackTrace();
}
response.setContentType(application/pdf);
response.setContentLength(reportBytes.length);
ServletOutputStream ouputStream = response.getOutputStream();
ouputStream.write(reportBytes, 0, reportBytes.length);
ouputStream.flush();
ouputStream.close();
return(null);
This will display the pdf, but the action class itself somehow get called a
second time as the above log statement is displayed twice.
I also tried to set the byte[] on the request and forward onto another page
which does:
%
byte[] reportBytes =
(byte[])request.getAttribute(REPORT_BYTES);
response.setContentType(application/pdf);
response.setContentLength(reportBytes.length);
ServletOutputStream ouputStream = response.getOutputStream();
ouputStream.write(reportBytes, 0, reportBytes.length);
ouputStream.flush();
ouputStream.close();
%
But this complains about: getOutputStream() has already been called for this
response
Any ideas?
-
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
--
Virtually,
Andre Van Klaveren
SCP
-
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
Re: Output PDF
Any time!
Virtually,
Andre Van Klaveren, SCP
On Mon, 14 Mar 2005 14:51:37 -0600, Brad Balmer [EMAIL PROTECTED] wrote:
Thanks for the great response. This should take care of all my issues.
-Original Message-
From: Andre Van Klaveren [mailto:[EMAIL PROTECTED]
Sent: Monday, March 14, 2005 2:39 PM
To: Struts Users Mailing List; [EMAIL PROTECTED]
Subject: Re: Output PDF
I'm assuming that your browser client is IE. If so, the reason your
Action is being called twice is because of a feature in IE 4.x+. If
your application returns data that is to be handled with an ActiveX
control (ie Adobe Acrobat Reader) the browser sends additional
requests to the server. In IE 4.x and 5 it actually sends three
requests. For IE 5.5+ it sends two.
Assuming that your using IE 5.5+, the first request is the original
request (duh), but then IE sends a second request to get the
content-type. Who knows why they can't figure this out on the first
request ;) This second request has it's userAgent header set to
contype. You can solve this problem and increase the performance of
your application by writing a Servlet filter that sits in front of
whatever Actions you have setup to serve PDF content. Have this
filter look at the userAgent header of each request. If it's set to
contype just send an an empty response back to the client with the
content type set to application/pdf. Simple as that.
Now, the reason your getting an exception in the second code snippet
you provided is because after you do your forward the JSP calls
response.getOutputStream(). This is done behind the scenes but you
can see it if you look at your generated Servlet code. This method
can only be called once during the lifestyle of the request, hence
your exception.
It's generally a bad idea to have a JSP produce binary content anyway.
They were designed for Text or HTML output.
I wrote a generic/reusable Servlet whose sole purpose in life is to
write binary content back to a client. I called it
BinaryOutputServlet. You put your binary data (byte[]) and the
content type of the data in the request scope and forward to it. It
gets the data and content type out of the request and writes it back
to the client. It can be used for any type of data this way. I would
recommend doing something similar since Actions are really for
control. By writing back to the client from an Action you are
violating the MVC model anyway.
I hope this helps. Oh, and you can read all about the feature of IE here:
http://support.microsoft.com/default.aspx?scid=kb;EN-US;q293792
Virtually,
Andre Van Klaveren, SCP
On Mon, 14 Mar 2005 14:01:48 -0600, Brad Balmer [EMAIL PROTECTED] wrote:
I'm using Jasper to create PDF's through my Actions and cannot figure out
a
good way to export the resulting byte[] to the user.
Currently the tail end of my Action class looks like this:
byte[] reportBytes = null;
File jasperReport = new File(location);
try {
reportBytes = JasperRunManager.runReportToPdf(jasperReport.getPath(),
parameters, dataSource);
log.info(Found : + reportBytes.length);
} catch (JRException e) {
e.printStackTrace();
}
response.setContentType(application/pdf);
response.setContentLength(reportBytes.length);
ServletOutputStream ouputStream = response.getOutputStream();
ouputStream.write(reportBytes, 0, reportBytes.length);
ouputStream.flush();
ouputStream.close();
return(null);
This will display the pdf, but the action class itself somehow get called
a
second time as the above log statement is displayed twice.
I also tried to set the byte[] on the request and forward onto another
page
which does:
%
byte[] reportBytes =
(byte[])request.getAttribute(REPORT_BYTES);
response.setContentType(application/pdf);
response.setContentLength(reportBytes.length);
ServletOutputStream ouputStream = response.getOutputStream();
ouputStream.write(reportBytes, 0, reportBytes.length);
ouputStream.flush();
ouputStream.close();
%
But this complains about: getOutputStream() has already been called for
this
response
Any ideas?
--
Virtually,
Andre Van Klaveren
SCP
-
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
--
Virtually,
Andre Van Klaveren
SCP
-
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
RE: Output PDF
This intrigued me, since our app also has some generated PDFs. Sure
enough, there's a double-get occurring w/ our IE clients (IE 6.0).
Problem is that the USER_AGENT header for get #1 #2 are identical.
In fact, the only difference I can see in all headers is that get #1 has
an ACCEPT-LANGUAGE header, whereas get #2 does not. Everything else
is the same
So what gives? Did MS fix the wrong end of this bug in IE6? Is it
safe to just look for the existence of the ACCEPT-LANGUAGE header?
Thanks,
- Scott
-Original Message-
From: Andre Van Klaveren [mailto:[EMAIL PROTECTED]
Sent: Monday, March 14, 2005 3:39 PM
To: Struts Users Mailing List; [EMAIL PROTECTED]
Subject: Re: Output PDF
I'm assuming that your browser client is IE. If so, the reason your
Action is being called twice is because of a feature in IE 4.x+. If
your application returns data that is to be handled with an ActiveX
control (ie Adobe Acrobat Reader) the browser sends additional requests
to the server. In IE 4.x and 5 it actually sends three requests. For
IE 5.5+ it sends two.
Assuming that your using IE 5.5+, the first request is the original
request (duh), but then IE sends a second request to get the
content-type. Who knows why they can't figure this out on the first
request ;) This second request has it's userAgent header set to
contype. You can solve this problem and increase the performance of
your application by writing a Servlet filter that sits in front of
whatever Actions you have setup to serve PDF content. Have this filter
look at the userAgent header of each request. If it's set to contype
just send an an empty response back to the client with the content type
set to application/pdf. Simple as that.
Now, the reason your getting an exception in the second code snippet you
provided is because after you do your forward the JSP calls
response.getOutputStream(). This is done behind the scenes but you can
see it if you look at your generated Servlet code. This method can only
be called once during the lifestyle of the request, hence your
exception.
It's generally a bad idea to have a JSP produce binary content anyway.
They were designed for Text or HTML output.
I wrote a generic/reusable Servlet whose sole purpose in life is to
write binary content back to a client. I called it BinaryOutputServlet.
You put your binary data (byte[]) and the content type of the data in
the request scope and forward to it. It gets the data and content type
out of the request and writes it back to the client. It can be used for
any type of data this way. I would recommend doing something similar
since Actions are really for control. By writing back to the client
from an Action you are violating the MVC model anyway.
I hope this helps. Oh, and you can read all about the feature of IE
here:
http://support.microsoft.com/default.aspx?scid=kb;EN-US;q293792
Virtually,
Andre Van Klaveren, SCP
On Mon, 14 Mar 2005 14:01:48 -0600, Brad Balmer [EMAIL PROTECTED]
wrote:
I'm using Jasper to create PDF's through my Actions and cannot figure
out a good way to export the resulting byte[] to the user.
Currently the tail end of my Action class looks like this:
byte[] reportBytes = null;
File jasperReport = new File(location);
try {
reportBytes = JasperRunManager.runReportToPdf(jasperReport.getPath(),
parameters, dataSource);
log.info(Found : + reportBytes.length);
} catch (JRException e) {
e.printStackTrace();
}
response.setContentType(application/pdf);
response.setContentLength(reportBytes.length);
ServletOutputStream ouputStream = response.getOutputStream();
ouputStream.write(reportBytes, 0, reportBytes.length);
ouputStream.flush();
ouputStream.close();
return(null);
This will display the pdf, but the action class itself somehow get
called a second time as the above log statement is displayed twice.
I also tried to set the byte[] on the request and forward onto another
page which does:
%
byte[] reportBytes =
(byte[])request.getAttribute(REPORT_BYTES);
response.setContentType(application/pdf);
response.setContentLength(reportBytes.length);
ServletOutputStream ouputStream =
response.getOutputStream();
ouputStream.write(reportBytes, 0, reportBytes.length);
ouputStream.flush();
ouputStream.close();
%
But this complains about: getOutputStream() has already been called
for this response
Any ideas?
--
Virtually,
Andre Van Klaveren
SCP
-
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
-
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
Re: Output PDF
Sounds like in 6.0 they went back to sending two extra requests
instead of one extra. I'm assuming this from your statement. I
haven't verified this with our application. The first request (the
one generated by the user to get the PDF) should still have a valid
userAgent (MSIE). The subsequent requests should have the conType
userAgent. Can you verify this?
Virtually,
Andre Van Klaveren, SCP
On Mon, 14 Mar 2005 13:21:25 -0800, Scott Piker [EMAIL PROTECTED] wrote:
This intrigued me, since our app also has some generated PDFs. Sure
enough, there's a double-get occurring w/ our IE clients (IE 6.0).
Problem is that the USER_AGENT header for get #1 #2 are identical.
In fact, the only difference I can see in all headers is that get #1 has
an ACCEPT-LANGUAGE header, whereas get #2 does not. Everything else
is the same
So what gives? Did MS fix the wrong end of this bug in IE6? Is it
safe to just look for the existence of the ACCEPT-LANGUAGE header?
Thanks,
- Scott
-Original Message-
From: Andre Van Klaveren [mailto:[EMAIL PROTECTED]
Sent: Monday, March 14, 2005 3:39 PM
To: Struts Users Mailing List; [EMAIL PROTECTED]
Subject: Re: Output PDF
I'm assuming that your browser client is IE. If so, the reason your
Action is being called twice is because of a feature in IE 4.x+. If
your application returns data that is to be handled with an ActiveX
control (ie Adobe Acrobat Reader) the browser sends additional requests
to the server. In IE 4.x and 5 it actually sends three requests. For
IE 5.5+ it sends two.
Assuming that your using IE 5.5+, the first request is the original
request (duh), but then IE sends a second request to get the
content-type. Who knows why they can't figure this out on the first
request ;) This second request has it's userAgent header set to
contype. You can solve this problem and increase the performance of
your application by writing a Servlet filter that sits in front of
whatever Actions you have setup to serve PDF content. Have this filter
look at the userAgent header of each request. If it's set to contype
just send an an empty response back to the client with the content type
set to application/pdf. Simple as that.
Now, the reason your getting an exception in the second code snippet you
provided is because after you do your forward the JSP calls
response.getOutputStream(). This is done behind the scenes but you can
see it if you look at your generated Servlet code. This method can only
be called once during the lifestyle of the request, hence your
exception.
It's generally a bad idea to have a JSP produce binary content anyway.
They were designed for Text or HTML output.
I wrote a generic/reusable Servlet whose sole purpose in life is to
write binary content back to a client. I called it BinaryOutputServlet.
You put your binary data (byte[]) and the content type of the data in
the request scope and forward to it. It gets the data and content type
out of the request and writes it back to the client. It can be used for
any type of data this way. I would recommend doing something similar
since Actions are really for control. By writing back to the client
from an Action you are violating the MVC model anyway.
I hope this helps. Oh, and you can read all about the feature of IE
here:
http://support.microsoft.com/default.aspx?scid=kb;EN-US;q293792
Virtually,
Andre Van Klaveren, SCP
On Mon, 14 Mar 2005 14:01:48 -0600, Brad Balmer [EMAIL PROTECTED]
wrote:
I'm using Jasper to create PDF's through my Actions and cannot figure
out a good way to export the resulting byte[] to the user.
Currently the tail end of my Action class looks like this:
byte[] reportBytes = null;
File jasperReport = new File(location);
try {
reportBytes = JasperRunManager.runReportToPdf(jasperReport.getPath(),
parameters, dataSource);
log.info(Found : + reportBytes.length);
} catch (JRException e) {
e.printStackTrace();
}
response.setContentType(application/pdf);
response.setContentLength(reportBytes.length);
ServletOutputStream ouputStream = response.getOutputStream();
ouputStream.write(reportBytes, 0, reportBytes.length);
ouputStream.flush();
ouputStream.close();
return(null);
This will display the pdf, but the action class itself somehow get
called a second time as the above log statement is displayed twice.
I also tried to set the byte[] on the request and forward onto another
page which does:
%
byte[] reportBytes =
(byte[])request.getAttribute(REPORT_BYTES);
response.setContentType(application/pdf);
response.setContentLength(reportBytes.length);
ServletOutputStream ouputStream =
response.getOutputStream();
ouputStream.write(reportBytes, 0, reportBytes.length);
ouputStream.flush();
ouputStream.close
