Ok, so this approach of writing to disk after reading the database is not working at all. I thought you were saying previously that was working up to a point, but then failing for new products.
I know its completely possible to add images the root of a Web-App folder after deployment and have Tomcat "see" them. Are you by chance running Tomcat behind Apache Httpd or some other server? On Wed, Jun 10, 2009 at 1:10 PM, Lyallex <lyal...@gmail.com> wrote: > Hi > > I'll try to explain in as few words as possible. > > When I upload a new product I store the image data and the text in the > database. I did this to try and separate the data from the application > with the intention of eventually having the data reside on a separate > device optimised for serving data ... well that was my original > thinking anyway. > > At the moment, when I load an image I use a proxy servlet and extract > the imageid from the 'Product' (p below) > > <img > src="ImageProxy?<%=WebConstants.IMAGE_ID%>=<%=p.calculateImageId()%>... > etc '/> > > This gets the image from the database and displays it in the page. > > This is clunky and slow and the image is not cached by the browser > > So, when a user views an item detail I do something like this > > getProductDetails?productId='whatever' > > In the GetProductDetails servlet I check the disk cache to see if the > image is there, if not I get it from the database an write it to the > cache, just one database access as opposed to many, the next time > anyone sees that item the images are already cached. > > now, in the jsp I can use <img > src="imagecache/<%=p.getProductId()%>_thumb.jpg" ...' etc/> > > In other words, as opposed to getting an anonymous byte stream and > displaying it in the browser I'm now accessing a named image and the > browser caches it. It all works beautifully apart from the fact that > it appears the DefaultServlet will not load resources that have been > written to disk after the server has been started. If I restart the > server I can see my images, but only the ones loaded thus far ... > > Anyway, I'm currently looking at the serveResource() method in the > DefaultServlet to try and figure out if it is possible to configure it > to load resoures that have appeared after the server has started ... > it doesn't look like it is possible which is slightly depressing ... > unless of course I am missing something. > > Surely this is not an unusual requirement, how do others deal with > serving up images that have been uploaded after the server has > started. > > Anyway > > Thanks for taking the time to reply > lyallex > > > 2009/6/10 Jonathan Mast <jhmast.develo...@gmail.com>: > > So you are actually storing the image data in the database, as opposed to > > the filepath? interesting... > > > > So your webapp accesses the image data as needed and writes it to > imagecache > > dir? Is this feature not working? i don't understand what exactly the > issue > > is that you are having. please explain. > > > > > > > > On Wed, Jun 10, 2009 at 9:41 AM, Lyallex <lyal...@gmail.com> wrote: > > > >> apache-tomcat-6.0.16 > >> jdk1.6.0_03 > >> > >> Dev box : Windows > >> Deployment box: Linux > >> > >> Hi > >> > >> I've read some other posts that seem to be asking similar questions > >> but I can't find the answer so far. > >> maybe someone here would be kind enough to give me a hint > >> > >> I have a retail application that stores the product images in a > database. > >> Each product can have many images and products are being uploaded all > the > >> time. > >> > >> Fetching images from the database every time results in a clunky page > >> load so I want to cache the images to disk > >> the first time an item is accessed my cache manager checks the disk > >> cache to see if images for that item are available. > >> If not it loads them onto the disk. > >> this happens in the servlet that serves the item details up so the > >> images are in the disk cache before the request is forwarded to the > >> view (jsp) > >> In the jsp I access the images from the disk cache. > >> > >> The problem is, the first time I access the item details the images > >> are written to the cache which resides directly under the > >> context root but they are not loaded in the view. > >> If I restart tomcat the images disply fine so I know all the caching > >> is working correctly. > >> > >> I can't restart tomcat everytime I upload a new product so how can I > >> force tomcat to recognise the new images 'on the fly' so as to speak? > >> The application is running as the ROOT application on the server and > >> is the only application being served. > >> > >> An example image might be > >> ../apache-tomcat-6.0.16/webapps/ROOT/imagecache/8000030_main.jpg > >> (example) > >> > >> I'm quite happy that the imagecache is deleted everytime I redeploy > >> the application because the application is starting to stabilise and > >> once I have this last problem ironed out > >> I will only be doing irregular maintenance. The faster loading of > >> images is more than enough compensation. > >> > >> I can't use symbolic links to place the imagecache outside the > >> application space because I develop on Windows and deploy to Linux > >> (historical, nothing I can do about it) > >> > >> Any ideas much appreciated. > >> > >> > >> Many thanks > >> lyallex > >> > >> --------------------------------------------------------------------- > >> To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org > >> For additional commands, e-mail: users-h...@tomcat.apache.org > >> > >> > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org > For additional commands, e-mail: users-h...@tomcat.apache.org > >
