It sounds like you have enough ways to do it and just asking what would be the best way or if there is another way to more efficiently handle your situation. Yes?
I cannot think of one personally. If your only means is HTTP, your only choice is evaluating the response to determine if something exists as far as I can tell. If the request cant be served, I assume you get a typical response code like a 404? Not sure what else there is. Nothing is real efficient when it comes to file io like functions via HTTP. We tried to have a standard once for serving up file like functions via HTTP but it becomes complex if you wanted to perform other file-io activities like list files, seeing if they exist, list directories, get file modified dates/times, delete files etc. Almost felt like putting a square peg in a round hole for us(Course I might be behind on the latest and greatest of HTTP). If I was concerned about managing unreliable sources, I probably would have attempted a proxy-like solution through a struts action at first crack to do as little coding as possible but it sounds like your past the first crack at it? I will offer up my solution for battering by the populous here. You could set up a specific action which serves the images for remote sites. Your JSP would have an action with a parameter passing in the remote URL of the remote site. Since you indicated that you semi-manage the reference of the image but cant guarantee that it actually exists since its elsewhere, this solution might work good(i.e. you are supplying the remote URL?). You could open a request to the remote site of your URL in a Struts Action instead, if you get a success, take the content of the response and shove it into your response, otherwise, shove the no-image found file(from your server) into the response(Make sure you return a null action mapping) since your writing off the content directly. Your JSP Might look like this: <img src="http://www.mysites.com/proxyRemoteImage.do?remoteURL=<bean:write name="thisForm" property="remoteURL"/>" width="300" height="300" border=0> Semi/Pseudo Code for proxyRemoteImage.do action: URL theRemoteImageURL = New URL(yourForm.getRemoteURL()); Open theRemoteImageURL Get Response If Response Code good shove content, content type and all the other stuff you need into your response of your users request(that might get rid of you having to handle file type conditions). If Response Code is bad, get the no image file data and shove that into the response instead Return null from execute method. I am sure you can gather upsides and downsides to the proxy-like solution. Just thought I would throw it into the pool of options. Not a great option but at least as simple I think. Not sure if you consider it more flexible or not. Hope you find what your looking for. -----Original Message----- From: CRANFORD, CHRIS [mailto:[EMAIL PROTECTED] Sent: Tuesday, June 15, 2004 4:44 PM To: '[EMAIL PROTECTED]' Subject: RE: Rendering Images Ken, That is what I'd like to do. Have an image which is rendered in the case when the defined image cannot be loaded. the problem I have is that our database record says that an image should exist, but the manufacturer/supplier didn't provide it to us... thus I need a way to check if that image does exist to test that condition. thanks, chris ps - these images are maintained by a second webapp that is on a different web server all together due to space requirements. so i have to do testing via a HTTP request or something i would think, no? -----Original Message----- From: Linck, Ken To: [EMAIL PROTECTED] Sent: 6/15/2004 2:32 PM Subject: RE: Rendering Images Just curious but why not just manually make this file once and return it when a real image is not found on disk? Why bother creating one on the fly every time? Is it different from request to request? We had done something similar. We created a static image file on disk and return that when a real one is not available. I think we used a struts condition if tag testing if a real one exists otherwise use the URL to not found image. -----Original Message----- From: CRANFORD, CHRIS [mailto:[EMAIL PROTECTED] Sent: Tuesday, June 15, 2004 1:21 PM To: '[EMAIL PROTECTED]' Subject: Rendering Images I'm curious if anyone has used or knows of an open-source image rendering servlet that permits rendering a "no image found" image file if the referenced image to be rendered does not exist on disk. Thanks _______________________________________________________ Chris Cranford Programmer/Developer SETECH Inc. & Companies 6302 Fairview Rd, Suite 201 Charlotte, NC 28210 Phone: (704) 362-9423, Fax: (704) 362-9409, Mobile: (704) 650-1042 Email: [EMAIL PROTECTED] --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
