CODEWITHSUNDEEP
javaimage
jacekn
jacekn

Reputation: 1541

Displaying images from outside of java application context.

This was a question about testing file upload functionality using a local java server on Windows 7 platform. Since the question evolved with Marko's input, I have edited it, so that those who run into the same challenge do not waste time on evolution details and reach conclusions sooner.

The challenge was to direct uploaded file to a folder outside of the WAR structure and successfully read it from there. For example: upload an image into c:/tmp/ and then redirect to a confirmation page that displays the image <img src="c:/tmp/test.jpg" />. The upload worked but image would not be displayed. And based on Marko's input, this makes sense because browser sitting at localhost will refuse to load anything from local disk structure using c:. Maybe these are security considerations similar to those with file input control where we cannot set a default path...

The following tag will work in a locally created .html file but when pasted into a jsp, it won't work. And the difference is that browser uses localhost to get to the jsp.

<img src="c:/tmp/test.jpg" />

Solutions

I think that Marko's answer pretty much defines what needs to be done. While I didn't go with that approach, it clearly is the better way to do it and I will accept that as the answer. Thanks, Marko!

For those who don't want to bother installing a Web server and are willing to live with a bit of a hack, here's what I have done. Again, I didn't want to upload files into my WAR structure because I would then need to remember about clearing that folder before deploying to the server. But that upload folder still needs to be accessible, so I simply created another dummy project and put that upload folder under its WebContent. This works for the purposes of my local testing. The only nuisance is that after uploading a file, I need to refresh the dummy project's WebContent in Eclipse. 

config.properties

#for uploading files
fileUploadDirectory=C:/javawork/modelsite/tmp/WebContent

#for building html links
publicFileServicePrefix=http://localhost:8080/tmp

<img src="http://localhost:8080/tmp/test.jpg" />  // this works - tmp is the name of my dummy project.

Upvotes: 0

Views: 2875

Answers (1)

Marko Topolnik
Marko Topolnik

Reputation: 200226

If you are citing literally the HTML that goes to the browser (the one that you access via "vieew source") then this has nothing to do with Java. The browser is the one who interprets these links. If they fail to load, the problem is in the browser/file system.

UPDATE

According to the results of your additional diagnostics, I conclude that the browser (sensibly!) refuses to load anything from your local disk if it is referenced from an HTML file coming from an internet URL, even when that URL is localhost.

UPDATE 2

(Deleted, irrelevant)

UPDATE 3

However you handle the files uploaded to the server, it's definitely not going to look like your solution -- the file is on the server's local filesystem, not client's. This sort of thing can be handled at the Apache HTTP server level -- reserve an URL section for static content and configure Apache with a base directory from which to serve the static content. Even if you run the server locally, on the same machine where you test it, you still need to go through the network interface.

Upvotes: 1

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