Oh, sorry, mean to include that if you add this to a quickstart, you can test with URL:
http://localhost:8080/foo http://localhost:8080/foo?text=fff&width=200 -- Jeremy Thomerson http://www.wickettraining.com On Fri, Dec 26, 2008 at 12:48 AM, Jeremy Thomerson < jer...@wickettraining.com> wrote: > I spent a while playing with this, and indeed - it is much more difficult > than it should be (or I missed something that one of the core devs can point > out. I really hope one of them can review this and point me to an easier > way. But in the meantime, this should work for you. > > First, let's start with the basics. In your web application class, you'll > add a shared resource and mount it to whatever path you want: > > public static final String IMAGE_KEY = "jrtimage".intern(); > > @Override > protected void init() { > super.init(); > getSharedResources().add(IMAGE_KEY, new MyImage()); > mountSharedResource("foo", new > ResourceReference(IMAGE_KEY).getSharedResourceKey()); > } > > Then, you can include it in your page: > JAVA: add(new Image("img", new > ResourceReference(WicketApplication.IMAGE_KEY))); > HTML: <img wicket:id="img" /> > > Okay, so what was that "MyImage"? It is the class that creates your > dynamic image. Read the long comments in the class explaining the nuances > of doing it this way. > private static class MyImage extends DynamicImageResource { > private static final long serialVersionUID = 1L; > ThreadLocal<String> mText = new ThreadLocal<String>(); > ThreadLocal<Integer> mWidth = new ThreadLocal<Integer>(); > @Override > public IResourceStream getResourceStream() { > // see note below on why we get parameters in this method > int width = 300; > String text = "Hello World!"; > String w = ((String[]) getParameters().get("width"))[0]; > if (w != null && "".equals(w.trim()) == false) { > try { > width = Integer.parseInt(w); > } catch(NumberFormatException nfe) { > //no-op > } > } > String t = ((String[]) getParameters().get("text"))[0]; > if (t != null && "".equals(t.trim()) == false) { > text = t; > } > mText.set(text); > mWidth.set(width); > return super.getResourceStream(); > } > @Override > protected byte[] getImageData() { > /* > Unfortunately by the time we get here, the request target has already > been switched, and is no longer an instance of > ISharedResourceRequestTarget > and the getParameters() method no longer returns any parameters, > presumably > because the request target has been switched to a > ResourceStreamRequestTarget > > Therefore, we must override getResourceStream above (while params > still available) > so that we can get the parameters there and store them in a > ThreadLocal > > NOTE: I haven't tested the ThreadLocal here at all. Presumably it > will be okay. > I don't think you could use regular member fields because multiple > requests > could be operating on this object at the same time - I'm pretty sure, > but haven't > double checked. > */ > BufferedImage img = new BufferedImage(mWidth.get(), 100, > BufferedImage.TYPE_INT_RGB); > Graphics gr = img.createGraphics(); > gr.setColor(Color.BLACK); > gr.fillRect(0, 0, mWidth.get(), 100); > gr.setFont(new Font("Arial", Font.PLAIN, 16)); > gr.setColor(Color.WHITE); > gr.drawString(mText.get(), 25, 25); > gr.drawString("Width: " + mWidth.get(), 25, 45); > mText.set(null); > mWidth.set(null); > return toImageData(img); > } > } > -- > Jeremy Thomerson > http://www.wickettraining.com > > > On Thu, Dec 25, 2008 at 11:03 PM, smallufo <small...@gmail.com> wrote: > >> Well , >> What I need is parsing URL and generating a corresponding image from >> BufferedImage , >> not a bookmarkable link to internal file resource... >> >> for example : >> http://localhost/app/myImage/text/Hello/width/500 >> >> This will generate a 500x500 png , containing a "Hello" String. >> > > > >
