Hi Daniele, just an idea:
@Override
protected byte[] getImageData() {
String basePath = "upload/images/";
Object name = logoModel.getObject();
File file = new File(".", basePath + name);
LoggerFactory.getLogger(getClass()).info("serving file: " + file);
try {
return IOUtils.toByteArray(new FileInputStream(file));
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
DefaultButtonImageResource img = new
DefaultButtonImageResource("Image not found");
InputStream defautImg =
img.getResourceStream().getInputStream();
byte[] bytes = new byte[defautImg.available()];
defautImg.read(bytes);
return bytes;
}
You can show an image with this message while not found an solution for the
null pointer exception.
On Wed, Sep 2, 2009 at 6:36 PM, Daniele Dellafiore <ilde...@gmail.com>wrote:
> Hi all, I use a DynamicWebResource to display images previously uploaded by
> user ion the context of my application. I have this DWR subclass:
>
> class LogoResource extends DynamicImageResource {
>
> private final IModel logoModel;
>
> public LogoResource(IModel model) {
> this.logoModel = model;
> }
>
> @Override
> protected byte[] getImageData() {
> String basePath = "upload/images/";
> Object name = logoModel.getObject();
> File file = new File(".", basePath + name);
> LoggerFactory.getLogger(getClass()).info("serving file: " + file);
> try {
> return IOUtils.toByteArray(new FileInputStream(file));
> } catch (FileNotFoundException e) {
> e.printStackTrace();
> } catch (IOException e) {
> e.printStackTrace();
> }
> return null;
> }
> }
>
> now, when the file is found, everything is ok.
> When it is not, I receive a NullPo9nterException, this is the output when
> you can see my log and then the begin of the trace:
>
> INFO - LogoResource - serving file: ./upload/images/null
> ERROR - RequestCycle -
> java.lang.NullPointerException
> at java.io.ByteArrayInputStream.<init>(ByteArrayInputStream.java:89)
> at
>
> org.apache.wicket.markup.html.DynamicWebResource$1.getInputStream(DynamicWebResource.java:221)
>
> at
>
> org.apache.wicket.request.target.resource.ResourceStreamRequestTarget.respond(ResourceStreamRequestTarget.java:160)
>
> at
>
> org.apache.wicket.request.AbstractRequestCycleProcessor.respond(AbstractRequestCycleProcessor.java:105)
>
> at org.apache.wicket.RequestCycle.respond(RequestCycle.java:1267)
>
> This is annoying and, more important, it seems to cause the page not to
> reload properly. In fact when after a submit I call a setResponse on the
> same page, the page is not reloaded.
>
> At the end of all the exceptions, I get:
>
> WARN - DataRequestCycle - Completed exception handling for
> request [requestcy...@1ec3ffd thread=10193...@qtp-28693170-2]
> INFO - DataRequestCycle - Request ended
> [requestcy...@1ec3ffdthread=10193106@qtp-28693170-2](time:
> 33
>
> And the page has the same URL as before, correclty, but not the new
> rendering: If I reload the page, I get the new stuff.
>
> In the same page I have other forms, with the same setResponse onSubmit,
> that work perfectly.
> Do you think that these exceptions could be the problem for the undone
> refresh? Or maybe is better to look elsewhere?
>
> And, in any case, there is a clean way to avoid the getImageData to be
> called if I do not have a file for the image?
>
> Thanks.
>
> --
> Daniele Dellafiore
> http://blog.ildella.net
> http://twitter.com/ildella
>
