Re: [Wicket-user] best practice for uploading and using content (images) with wicket?
Well, thanks a lot, thats really much more simple then i figured =P. Maybe
any pointers why the stream from the file system doesnt work? ;)
igor.vaynberg wrote:
your problem is not retreiving the data from the db - it is the weird
stuff
you try to do when stream it back to the browser. why all the awt image
stuff? all you have to do is read the byte array from the db and stream it
back to the browser.
here is some pseudo code
add(new Image(myimage) {
Resource getResource() { return new ByteArrayResource(getBytesFromDb());
}
}
if you really want to resize the image to 200x200 before storing it in the
db or creating a thumbnail then i would look over that wiki example and
extract the resizing logic - but if all you want to do is stream it back
then the above will do.
-Igor
On 8/22/06, Sebastian Pflugbeil
[EMAIL PROTECTED] wrote:
Hi Wicket Team and Wicket Mailinglist!
As this is my first post on this list, I would like to introduce myself.
My name is Sebastian and I am working on a university project, comparing
Java web frameworks. As you might guess, my primary topic is the Wicket
framework ;). I am not what one would call a programmer or coder, I
guess.
Rather someone familiar with the underling concepts, but sometimes a bit
lots with the actual implementations of a certain language. So please
excuse
me, if my questions are stupid ;).
My problem at this moment is the following. I need to implement a feature
in wicket that lets me upload images to a webpage and then use those
images
to be displayed on certain pages. It doesn't really matter if the images
are
stored on the file system or in a database. I am not looking for a
solution
to an explicit problem but rather for a best practice that shows how the
wicket framework supports such a feature.
I have tried to read up on anything I could find addressing such a
feature. But everything I got so far is either way beyond my scope of
understanding, not offering enough to archive the goal or just not
working
as I understand it should.
I have tried to read the example in the wiki (
http://www.wicket-wiki.org.uk/wiki/index.php/*UploadDownload*http://www.wicket-wiki.org.uk/wiki/index.php/UploadDownload),
but I can not really follow it. Too many libraries used that are not
included and overall to confusing for a non professional like myself.
I did understand the example for the upload in the wikiexamples though.
No
problems writing files to disk or even to database, following that
example
code.
My attempt to store images in the Database is looking something like
this:
To write to the Database, I use this code sniped:
public final void onSubmit()
{
try
{
// get the content of the upload field
final FileUpload upload_image =
upload.getFileUpload();
// create a byte array of the uploaded item
byte[] bild = upload_image.getBytes();
if(upload_image != null)
{
**write byte[] to database**
}
}
catch (Exception e) { }
}
So far so good. Got my byte array stored. The source file is a jpeg
image.
I am not sure if I miss some kind cast here to let the system know what
*sort* of byte array it should use.
When I try to retrieve the image from the database, I use the following
code:
public ResourceReference getImage()
{
return new ResourceReference(some.class, bild)
{
public BufferedDynamicImageResource newResource()
{
try
{
// get the byte[] from DB
byte[] bild = a.getBild();
// create a buffered image template
BufferedDynamicImageResource resource = new
BufferedDynamicImageResource();
BufferedImage image = new BufferedImage(200,
200, BufferedImage.TYPE_INT_RGB);
// transform the byte[] back to an image (does it work that way? How does
// java know it was a jpeg before and not a gif for example?)
java.awt.Image i = Toolkit.getDefaultToolkit
().createImage(bild);
// convert image to buffered image
image.getGraphics().drawImage(i, 0, 0,
null);
Graphics g = image.getGraphics();
g.drawImage(i, 0, 0, null);
g.dispose();
// return the image
resource.setImage(image);
return resource;
}
catch
Re: [Wicket-user] best practice for uploading and using content (images) with wicket?
this is Java - we have no pointers :P
basically, if you want to get the data from a file you do it a bit different
as from a DB stream, if you look here, youll see the basic behind IO here:
http://www.physik.uni-muenchen.de/kurs/Computing/java/node36.html
(its german, so u will understand it easily)
Regards,
Korbinian
-Ursprüngliche Nachricht-
Von: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] Im Auftrag
von Sebastian Pflugbeil
Gesendet: Mittwoch, 23. August 2006 11:24
An: wicket-user@lists.sourceforge.net
Betreff: Re: [Wicket-user] best practice for uploading and
using content (images) with wicket?
Well, thanks a lot, thats really much more simple then i
figured =P. Maybe any pointers why the stream from the file
system doesnt work? ;)
igor.vaynberg wrote:
your problem is not retreiving the data from the db - it is
the weird
stuff you try to do when stream it back to the browser. why all the
awt image stuff? all you have to do is read the byte array
from the db
and stream it back to the browser.
here is some pseudo code
add(new Image(myimage) {
Resource getResource() { return new
ByteArrayResource(getBytesFromDb());
}
}
if you really want to resize the image to 200x200 before
storing it in
the db or creating a thumbnail then i would look over that wiki
example and extract the resizing logic - but if all you
want to do is
stream it back then the above will do.
-Igor
On 8/22/06, Sebastian Pflugbeil
[EMAIL PROTECTED] wrote:
Hi Wicket Team and Wicket Mailinglist!
As this is my first post on this list, I would like to
introduce myself.
My name is Sebastian and I am working on a university project,
comparing Java web frameworks. As you might guess, my
primary topic
is the Wicket framework ;). I am not what one would call a
programmer
or coder, I guess.
Rather someone familiar with the underling concepts, but
sometimes a
bit lots with the actual implementations of a certain language. So
please excuse me, if my questions are stupid ;).
My problem at this moment is the following. I need to implement a
feature in wicket that lets me upload images to a webpage and then
use those images to be displayed on certain pages. It
doesn't really
matter if the images are stored on the file system or in a
database.
I am not looking for a solution to an explicit problem but
rather for
a best practice that shows how the wicket framework
supports such a
feature.
I have tried to read up on anything I could find addressing such a
feature. But everything I got so far is either way beyond
my scope of
understanding, not offering enough to archive the goal or just not
working as I understand it should.
I have tried to read the example in the wiki (
http://www.wicket-wiki.org.uk/wiki/index.php/*UploadDownload*http://
www.wicket-wiki.org.uk/wiki/index.php/UploadDownload),
but I can not really follow it. Too many libraries used
that are not
included and overall to confusing for a non professional
like myself.
I did understand the example for the upload in the
wikiexamples though.
No
problems writing files to disk or even to database, following that
example code.
My attempt to store images in the Database is looking
something like
this:
To write to the Database, I use this code sniped:
public final void onSubmit()
{
try
{
// get the content of the upload field
final FileUpload upload_image =
upload.getFileUpload();
// create a byte array of the uploaded item
byte[] bild = upload_image.getBytes();
if(upload_image != null)
{
**write byte[] to database**
}
}
catch (Exception e) { }
}
So far so good. Got my byte array stored. The source file
is a jpeg
image.
I am not sure if I miss some kind cast here to let the system know
what
*sort* of byte array it should use.
When I try to retrieve the image from the database, I use the
following
code:
public ResourceReference getImage()
{
return new ResourceReference(some.class, bild)
{
public BufferedDynamicImageResource newResource()
{
try
{
// get the byte[] from DB
byte[] bild = a.getBild();
// create a buffered image template
BufferedDynamicImageResource
resource =
new BufferedDynamicImageResource
Re: [Wicket-user] best practice for uploading and using content (images) with wicket?
or look at the source of DownloadLink as it streams a file from disk-IgorOn 8/23/06, Korbinian Bachl
[EMAIL PROTECTED] wrote:this is Java - we have no pointers :Pbasically, if you want to get the data from a file you do it a bit different
as from a DB stream, if you look here, youll see the basic behind IO here:http://www.physik.uni-muenchen.de/kurs/Computing/java/node36.html
(its german, so u will understand it easily)Regards,Korbinian -Ursprüngliche Nachricht- Von: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]] Im Auftrag von Sebastian Pflugbeil Gesendet: Mittwoch, 23. August 2006 11:24
An: wicket-user@lists.sourceforge.net Betreff: Re: [Wicket-user] best practice for uploading and using content (images) with wicket?
Well, thanks a lot, thats really much more simple then i figured =P. Maybe any pointers why the stream from the file system doesnt work? ;) igor.vaynberg wrote:
your problem is not retreiving the data from the db - it is the weird stuff you try to do when stream it back to the browser. why all the awt image stuff? all you have to do is read the byte array
from the db and stream it back to the browser. here is some pseudo code add(new Image(myimage) { Resource getResource() { return new
ByteArrayResource(getBytesFromDb()); } } if you really want to resize the image to 200x200 before storing it in the db or creating a thumbnail then i would look over that wiki
example and extract the resizing logic - but if all you want to do is stream it back then the above will do. -IgorOn 8/22/06, Sebastian Pflugbeil
[EMAIL PROTECTED] wrote: Hi Wicket Team and Wicket Mailinglist!
As this is my first post on this list, I would like to introduce myself. My name is Sebastian and I am working on a university project, comparing Java web frameworks. As you might guess, my
primary topic is the Wicket framework ;). I am not what one would call a programmer or coder, I guess. Rather someone familiar with the underling concepts, but
sometimes a bit lots with the actual implementations of a certain language. So please excuse me, if my questions are stupid ;).
My problem at this moment is the following. I need to implement a feature in wicket that lets me upload images to a webpage and then use those images to be displayed on certain pages. It
doesn't really matter if the images are stored on the file system or in a database. I am not looking for a solution to an explicit problem but rather for a best practice that shows how the wicket framework
supports such a feature. I have tried to read up on anything I could find addressing such a feature. But everything I got so far is either way beyond
my scope of understanding, not offering enough to archive the goal or just not working as I understand it should. I have tried to read the example in the wiki (
http://www.wicket-wiki.org.uk/wiki/index.php/*UploadDownload*http://
www.wicket-wiki.org.uk/wiki/index.php/UploadDownload), but I can not really follow it. Too many libraries used that are not included and overall to confusing for a non professional
like myself. I did understand the example for the upload in the wikiexamples though. No problems writing files to disk or even to database, following that
example code. My attempt to store images in the Database is looking something like this:
To write to the Database, I use this code sniped: public final void onSubmit() {
try { // get the content of the upload field
final FileUpload upload_image = upload.getFileUpload(); // create a byte array of the uploaded item
byte[] bild = upload_image.getBytes(); if(upload_image != null)
{ **write byte[] to database** } }
catch (Exception e) { } } So far so good. Got my byte array stored. The source file
is a jpeg image. I am not sure if I miss some kind cast here to let the system know what *sort* of byte array it should use.
When I try to retrieve the image from the database, I use the following code: public ResourceReference getImage()
{ return new ResourceReference(some.class, bild) { public BufferedDynamicImageResource newResource()
{ try { // get the byte[] from DB
byte[] bild = a.getBild(); // create a buffered image template BufferedDynamicImageResource
resource = new BufferedDynamicImageResource(); BufferedImage image = new BufferedImage(200, 200, BufferedImage.TYPE_INT_RGB
); // transform the byte[] back to an image (does it work that way? How does // java know it was a jpeg before and not a gif for example?)
java.awt.Image i = Toolkit.getDefaultToolkit ().createImage(bild);// convert image to buffered image
image.getGraphics().drawImage(i, 0, 0, null);Graphics g = image.getGraphics
(); g.drawImage(i, 0, 0, null); g.dispose();
// return the image resource.setImage(image); return resource;
} catch (Exception e) { } } };
} This leads
Re: [Wicket-user] best practice for uploading and using content (images) with wicket?
Hi, I haven't read through your whole email, but the cdapp example in wicket-contrib-examples which you can find in the wicket-stuff repository has functionality for uploading an image (edit details of a cd), which is then stored in the database. That image is then displayed as a thumbnail and the full image is displayed in a popup when you click on the image. I suggest you check that example out and see whether that helps you. Rgds, Eelco - Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnkkid=120709bid=263057dat=121642 ___ Wicket-user mailing list Wicket-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/wicket-user
Re: [Wicket-user] best practice for uploading and using content (images) with wicket?
your problem is not retreiving the data from the db - it is the weird stuff you try to do when stream it back to the browser. why all the awt image stuff? all you have to do is read the byte array from the db and stream it back to the browser.
here is some pseudo codeadd(new Image(myimage) { Resource getResource() { return new ByteArrayResource(getBytesFromDb()); }}img wicket:id=myimage width=200 height=200/
if you really want to resize the image to 200x200 before storing it in the db or creating a thumbnail then i would look over that wiki example and extract the resizing logic - but if all you want to do is stream it back then the above will do.
-IgorOn 8/22/06, Sebastian Pflugbeil [EMAIL PROTECTED]
wrote:
Hi Wicket Team and Wicket Mailinglist!
As this is my first post on this list, I would like
to introduce myself. My name is Sebastian and I am working on a university
project, comparing Java web frameworks. As you might guess, my primary topic is
the Wicket framework ;). I am not what one would call a programmer or coder, I guess.
Rather someone familiar with the underling concepts, but sometimes a bit lots
with the actual implementations of a certain language. So please excuse me, if
my questions are stupid ;).
My problem at this moment is the following. I need to
implement a feature in wicket that lets me upload images to a webpage and then
use those images to be displayed on certain pages. It doesn't really
matter if the images are stored on the file system or in a database. I am not looking
for a solution to an explicit problem but rather for a best practice that shows
how the wicket framework supports such a feature.
I have tried to read up on anything I could find addressing
such a feature. But everything I got so far is either way beyond my scope of
understanding, not offering enough to archive the goal or just not working as I
understand it should.
I have tried to read the example in the wiki (
http://www.wicket-wiki.org.uk/wiki/index.php/
UploadDownload),
but I can not really follow it. Too many libraries used that are not included
and overall to confusing for a non professional like myself.
I did understand the example for the upload in the
wikiexamples though. No problems writing files to disk or even to database,
following that example code.
My attempt to store images in the Database is looking
something like this:
To write to the Database, I use this code sniped:
public
final void onSubmit()
{
try
{
//
get the content of the upload field
final
FileUpload upload_image = upload.getFileUpload();
//
create a byte array of the uploaded item
byte[]
bild = upload_image.getBytes();
if(upload_image
!= null)
{
*write byte[] to database*
}
}
catch
(Exception e) { }
}
So far so good. Got my byte array stored. The source
file is a jpeg image. I am not sure if I miss some kind cast here to let the
system know what *sort* of byte array it should use.
When I try to retrieve the image from the database, I
use the following code:
public
ResourceReference getImage()
{
return
new ResourceReference(some.class, bild)
{
public
BufferedDynamicImageResource newResource()
{
try
{
// get
the byte[] from DB
byte[]
bild = a.getBild();
// create
a buffered image template
BufferedDynamicImageResource resource = new
BufferedDynamicImageResource();
BufferedImage
image = new BufferedImage(200, 200, BufferedImage.TYPE_INT_RGB);
//
transform the byte[] back to an image (does it work that way? How does
//
java know it was a jpeg before and not a gif for example?)
java.awt.Image
i = Toolkit.getDefaultToolkit().createImage(bild);
//
convert image to buffered image
image.getGraphics().drawImage(i,
0, 0, null);
Graphics
g = image.getGraphics();
g.drawImage(i,
0, 0, null);
g.dispose();
//
return the image
resource.setImage(image);
return
resource;
}
catch
(Exception e) { }
}
};
}
This leads to a black box in the place my image is
supposed to be. So I guess somewhere along the way I lose my image information.
My best guess is, that the problem lies in the image conversion. Jpeg isn't
a java.awt.image, I suppose.
But still leaves the question, does wicket offer
anything more to me to help me here? To make things (even) simpler for me?
The next attempt I took was storing images on the
file system. This went pretty well, as it pretty much is covered by the upload
example from the wicket examples. I was able to put the files in pretty much
any directory I liked, following that code. The problems started once again,
when I tried to retrieve and reuse the stored data. In the past I did a bit of PHP
programming and was used to just store my things anywhere on the web server as
a file and access them again via URL. This doesn't really work for me in the
java world (using jboss application server, ejb3, wicket), as the resources are
stored in archives and not easily written to
