We Keep Coding

Download file, open it locally, edit and then upload

I have a web application that let users download files normally, and then later they can upload them using a simple upload mechanism (choose the files from directory and stuff).
Here's what I want to do: to have and "EDIT" button on my app, that download the file and open it automatically from the user's local drive. Then I want to check if there are changes, to upload it back to the server. Or, provide a way to the user upload it easily.
The options I've come so far, are:
Signed Applets
I find applets slow and "ugly". But it's the winning choice so far. It could download and open the file easily and then have an upload button, to put the file back on the server.
HTML 5 (File API)
I started looking into this and liked what I saw. But a lot of things that I saw are for local uploads, drag and drop and this kind of stuff. I'm very new to this technology and I simple don't know if it's doable.
A desktop application
I don't like this one but it's still on the table. It could one that monitors a directory created by an applet (here it's again), check if there are changes and then upload it back to the server.
Can someone provide me some help? If a can do something like that with HTML 5 or if there's a better solution.

You can't upload files without user interaction in HTML even if you try HTML5. That's against web fundemantals. The user has to trigger the file upload in a way, drag&drop, browse and select file, etc.
Signed applets might be a better solution than a desktop application because of the pain of the deployment.
If this file that you want your users to edit is just text based, I suggesst using an HTML based editor like Google does it for Google Docs.

Preselect files in JUpload

I have a requirement to process an external request to populate a HTML form with the parameters mentioned in the URL. This part is working fine. However, the URL also contains paths to files present on the client machine and I want to upload those files from the client machine to the server without user interaction.
Since it is not possible with HTML/Javascript to programatically select files, I tried using the Applet approach using JUpload. However, I am not able to figure out, how to preselect a file on applet initialization. It is not necessary to upload the files right away, but I want atleast to select the files automatically. User can review the info and then submit the form. and files in the applet.
Is it possible with this library? Or direct me to some better path

OK, so I found my answer in a different library with similar name. With Smartwerkz JUpload we can pass a parameter preselectedFiles="filePath" and autostartUpload=true to preselect files and auto upload files without user interaction. I hope it will help someone someday.

Applet's .jar is messing up?

I'm trying to put an applet into a Google site (Because Domain hosting costs money). I've got that working, it is in the site. Now, I'm completely new to this, and my question is why doesn't my applet work?
The first thing I tried was uploading all the files to Google drive and accessing them there (My applet accesses multiple text files [ONLY READS, DOESN'T WRITE]) but that gave me a magic number error because FTP was ASCII which makes the class file all stupid, or so I've researched.
Okay, so I got a website that hosts files and it chooses the FTP (it automatically did Binary for my class files and ASCII for my text files) this made it better, but apparently unsigned applets can't access files other than the class file (I think).
So, I made a .jar for my applet using jar cvf [jar name].jar [blah blah blah, class files I need and text files I need]
I uploaded it to my file hosting site, and alas - Magic number error! 2 something something a lot of numbers. at this point, my HTML code looked like this:
<applet
codebase = "[URL for jar file]"
archive = "[jar file].jar"
code = "[class file].class"
width = ###
height = ###>
</applet>
paranoid that the site's FTP client was messing with my jar, I used FileZilla to upload to my server (an I selected the binary transfer type), which still resulted in a magic number error specifically 1347093252, which is the start of a zip file I believe (If it helps, when I click on the link for this file, it does in fact download).
I've probably done something stupid, but I would like to reiterate that I'm completely new at this.
If anyone could help, that would be awesome;
Thing's I already tried: Clearing my java cache and loading the applet (from here on, assume all the thing listed end with "and loading the applet"), clearing it again, closing my browser, clearing my java cache, clearing my cache - closing my browser - clearing my cache, reloading, changing computers, changing internet connections, changing computers and internet connections.

First of all, an unsigned applet can read files off of the server it came from. If you put dome text files in the same folder as your applet, the applet can grab then. I think the method is something like getDocumentBase to get the directory your applet wad loaded from. What you cannot do us access the local file system.
Making jar files with the command line is a pain. You might want to use an IDE like netbeans to build your project.

Multiple file uploader with previews

I'm trying to find something that will let users upload multiple files to a website. The requirements are that it let them easily select multiple files (preferably with something like check boxes) and that it displays a preview of the images they select.
I'd prefer to only use Javascript or Flash if possible, but Java is also an option (this needs to work on platforms where Silverlight isn't available).
So far all I've been able to find are things that use the native file selector (which doesn't show previews on Windows, and makes it unclear that you can select multiple by holding ctrl).
I'm not sure if the preview requirement is even possible, but it's the most important.

This is a firefox solution:
It uses the FileReader javascript object to load, display and upload images.
http://hacks.mozilla.org/2011/01/how-to-develop-a-html5-image-uploader/
It still doesnt show previews in the FileSelection dialog but at least allows you to preview the images before uploading.
And here is a ready made java applet solution:
http://jumploader.com/doc_overview.html

To upload multiple files I use RichFaces rich:fileUpload component.
Concerning the preview, I've got the similar problem and the best I found after couple of days of googling is following.
Alfresco has the same problem and resolved it with :
An open office which runs in server mode (socket) and all the office documents are sent by alfresco to open office in order to convert them in PDF
Those PDF are converted to .swf viewer thanks to SWFTOOLS
This .swf is integrated in the HTML
For images, it uses ImageMagick to create small version of the file I suppose
Personnaly, I will try to implement it this way :
Converting office documents to PDF thanks to open office in socket mode
Transform the first page of the PDF into a PNG thanks to JPedal library
Diplay that PNG to the end user
For images I would perhaps use ImageMagick too ... but for now, I'm using Seam Image.scaleToFit API

I am assuming 2 things here:
1) Some kind of client/enduser will be doing the file upload
2) You get some kind of say on what the client installs on their computer to help make this happen.
If this is the case, my first suggestion would be:
Give them FTP or SFTP client software to upload files. The php page you make can have a link to Filezilla, along with instructions on how to use it. ftp and sftp are THE protocols to use for transferring files. HTTP is just not designed(well) for it, nor are browsers.
Once the user has the (S)FTP client software installed, you can give them URL's to upload files to that are specific to their user account, and you can have a backend script process and load/move files that they upload. It's pretty easy to create a local temporary directory using a server side script, have the client upload files via ftp, then go back to the web browser and click a button that says "Done uploading, please process my stuff".
The browser can even give back confirmations on everything that gets uploaded/processed.

How to preview a file on the server in JBoss

I need some ideas on how I can best solve this problem.
I have a JBoss Seam application running on JBoss 4.3.3
What a small portion of this application does is generate an html and a pdf document based on an Open Office template.
The files that are generated I put inside /tmp/ on the filesystem.
I have tried with System.getProperties("tmp.dir") and some other options, and they always return $JBOSS_HOME/bin
I would like to choose the path $JBOSS_HOME/$DEPLOY/myEAR.ear/myWAR.war/WhateverLocationHere/
However, I don't know how I can programatically choose path without giving an absolute path, or setting $JBOSS_HOME and $DEPLOY.
Anybody know how I can do this?
The second question;
I want to easily preview these generated files. Either through JavaScript, or whatever is the easiest way. However, JavaScript cannot access the filesystem on the server, so I cannot open the file through JavaScript.
Any easy solutions out there?

Not sure how you are generating your PDFs, but if possible, skip the disk IO all together, stash the PDF content in a byte[] and flush it out to the user in a servlet setting the mime type to application/pdf* that responds to a URL which is specified by a link in your client or dynamically set in a <div> by javascript. You're probably taking the memory hit anyways, and in addition to skipping the IO, you don't have to worry about deleting the tmp files when you're done with the preview.
*****I think this is right. Need to look it up.

Not sure I have a complete grasp of what you are trying to achieve, but I'll give it a try anyway:
My assumption is that your final goal is to make some files (PDF, HTML) available to end users via a web application.
In that case, why not have Apache serve those file to the end users, so you only need your JBOSS application to know the path of a directory that is mapped to an Apache virtual host.
So basically, create a file and save it as /var/www/html/myappfiles/tempfile.pdf (the folder your application knows), and then provide http://mydomain.com/myappfiles (an Apache virtual host) to your users. The rest will be done by the web server.
You will have to set an environment variable or system property to let your application know where your folder resides (/var/www/html/myappfiles/ in this example).
Hopefully I was not way off :)

I agree with Peter (yo Pete!). Put the directory outside of your WAR and setup an environment variable pointing to this. Have a read of this post by Jacob Orshalick about how to configure environment variables in Seam :
As for previewing PDFs, have a look at how Google Docs handles previewing PDFs - it displays them as an image. To do this with Java check out the Sun PDF Renderer.

I'm not sure if this works in JBoss, given that you want a path inside a WAR archive, but you could try using ServletContext.getRealPath(String).
However, I personally would not want generated files to be inside my deployed application; instead I would configure an external data directory somewhere like $JBOSS_HOME/server/default/data/myapp

First, most platforms use java.io.tmpdir to set a temporary directory. Some servlet containers redefine this property to be something underneath their tree. Why do you care where the file gets written?
Second, I agree with Nicholas: After generating the PDF on the server side, you can generate a URL that, when clicked, sends the file to the browser. If you use MIME type application/pdf, the browser should do the right thing with it.