+1 to Ze's comment My reply assumed you had a reason why you *must* store images in DB. If you don't Ze is right that it is a very inefficient way to store and serve images.
On Mar 13, 9:04 am, Zé Vicente <josevicentec...@gmail.com> wrote: > Hi, > > I will give you my honestly opinion. It seems that you are new on the > subject and I can say that I have a lot of experience on that. > > First of all, don't store images on the database :) > > It is true that we can do it, but depending of what you are going to > do, the site of your database will be 90% images and 10% data. > > The images are always served by httpservers, even if you retrieve it > from the database. So if you store the images in the file system of > your httpserver, there is no need for network usage in case your > database is hosted in a different server. > > So, use the database just to store the path of your images. Then in > GWT, retrieve the object or list of objects that contains the path for > your images. Again in GWT, Create an Image object and set the src > property. > > That is all you need to do to display the image. > > What do you think? > > Regards, > José Vicente > > On Mar 13, 2:52 am, Itamar Ravid <itamar.ira...@gmail.com> wrote: > > > Don't forget however to set the content type on the response to an image of > > some type, otherwise the client's browser will try to download the picture > > rather than display it. > > > On Fri, Mar 13, 2009 at 2:28 AM, gregor <greg.power...@googlemail.com>wrote: > > > > I think Itamar is right, Jack, you should use a standard HttpServlet > > > for this, not GWT-RPC, because this sends the image over to the > > > browser as byte steam, and I don't think RPC can do that. > > > > First, I take it these are not images used in your UI (like icons > > > etc), 'cos those should go in an ImageBundle. I assume you know that & > > > these images are downloaded as user selections etc. > > > > 1) Consult your MySQL docs/forum to find out how to obtain an > > > InputStream for the image via JDBC. You want to pass an InputStream > > > back to your image download HttpServlet. You don't want to read out > > > the image bytes yet. > > > > 2) You write the HttpServlet something like this example (there are > > > lots of others around): > > > >http://snippets.dzone.com/posts/show/4629 > > > > Notice that the key is a looping read of the InputStream (which you > > > got from MySQL) that writes straight into the HttpServlet's response > > > OutputStream. Notice also it uses a buffer byte[] array. This is so > > > that your web server does not get it's memory clogged up with big > > > image byte arrays - the image bytes just get shunted from the DB > > > straight out to the browser via this buffer. Therefore set this buffer > > > small. Apache tend to use 2048 bytes. I think Oracle prefer 4096. That > > > sort of size for the buffer. Take care to set the response content > > > type so the browser knows what it's dealing with. > > > > 3) In your client you can set the Image widget's URL to your image > > > download HttpServlet adding a parameter for the image id. > > > > regards > > > gregor > > > > On Mar 12, 8:54 pm, "fatjack1...@googlemail.com" > > > <fatjack1...@googlemail.com> wrote: > > > > Hi, > > > > > I'm not too sure how to implement a HTTPServlet. Does anyone know how > > > > to use images using RPC? > > > > > Im really stuck on this. > > > > > On Mar 12, 8:43 pm, Itamar Ravid <itamar.ira...@gmail.com> wrote: > > > > > > The best way, IMO, is to not use GWT-RPC, but rather implement an > > > > > HttpServlet, that retrieves the data from the database and returns it > > > with > > > > > the appropriate Content-Type in response to a GET http request. Then, > > > you > > > > > simply place an image in your GWT code, with its source being the path > > > to > > > > > the servlet (defined in your web.xml), passing along any parameters > > > required > > > > > - such as the ID of the image in the database. > > > > > > On Thu, Mar 12, 2009 at 12:59 PM, fatjack1...@googlemail.com < > > > > > > fatjack1...@googlemail.com> wrote: > > > > > > > Hi, > > > > > > > I am new to loading images into GWT from MySQL and am abit lost on > > > the > > > > > > best way to do it. > > > > > > > I already have my image in the database. How do I retrieve it? I > > > > > > read > > > > > > somewhere that it can just be stored as a String. Is this correct? > > > > > > So > > > > > > my code on the server side would look like: > > > > > > > //Open database connection > > > > > > dc.openConnection(); > > > > > > resultSet = dc.statement.executeQuery(SELECT CategoryImage FROM > > > > > > itemcategory_table WHERE ItemType = 'Test'); > > > > > > > while(resultSet.next()) { > > > > > > String test = resultSet.getString(1); > > > > > > } > > > > > > > dc.closeConnection(); > > > > > > > Or have I got this completely wrong? > > > > > > > Next, I need to send this over to the client. What is the best way > > > > > > to > > > > > > send an image over from the server to the client and how should it > > > > > > be > > > > > > stored? > > > > > > > Any help on how to use images would be much appreciated! > > > > > > > Regards, > > > > > > Jack --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google Web Toolkit" group. 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