I am making Scouting Software (in Java) for my FRC robotics team. Scouting is like collecting data on other teams' robots during competition. It is absolutely critical that my program makes that process as simple and easy as possible. My program can save its data in two ways, one of which is by writing a .scout file to the user's hard drive. All this is working well, but as a finishing touch i would like to implement a way to associate .scout files with my program so that .scout files are opened with my program. It's like .docx for Microsoft Word. It associates .doc/.docx/...etc to itself such that when the user clicks on a file with those extensions, Word opens itself up and then opens the file the user clicked on. I want something like this for my application. Keep in mind, it is written in Java and meant to work on different operating systems (Windows, OSX, Ubuntu Linux, etc).
Does the program have a GUI? If so, launch it with Java Web Start.
JWS can associate a file-type with an application on Windows, OS X & *nix. Here is a demo. of the JNLP API file service that associates the .zzz file type with the demo. app.
Related
Need a program written in Java to close a .txt file as it opens (so that the user can, hopefully, not see it). How would I go about closing a .txt file as soon as it opens?
The alternatives to this way is to open the file on the secondary monitor or replace the text in the file instantly so the user cannot see this.
As I understand your question you want to intercept all requests, by any program running in a computer, to open any text file, and prevent that file from being accessed.
This is categorically beyond the capabilities of anything you can do in Java, or any "user-space" environment. Anything of this type would have to be done as part of the operating system, operating in privileged mode, and working with the filesystem drivers.
This could probably be done but would be operating-system specific and likely need to be written in C++ or assembler. Also it would require specific user action to be installed and would require superuser or administrator privileges.
This is not something within reach of a developer without significant OS kernel experience.
Sounds like you are trying to write ransomware?
Take notepad for example. You can open a file with notepad (right click and open with, or double clicking on the file if it is already associated with notepad) and it will display the contents of a file. I want to be able to open an xml file with the program that I am writing so that it can do some parsing and give a desired output. What sort of ways are there to do this in java? Do I have to ask for an argument to be passed into the program when it is opened? Would this be easier in C++ or some other language? If you need any further information please let me know -- this was the best way I could come up with to discribe my situation, which may be why my google searches have come up empty. Thank you in advance for your help!
You can associate an extension with a java jar and the file name will be passed as args[0] It doesn't get much simpler than that. I suggest you try it with a "hello world" program. ;)
display the contents of a file ..What sort of ways are there to do this in java?
Install/launch the app. using Java Web Start.
Java Web Start (JWS) is the Oracle Corporation technology used to launch rich client (Swing, AWT, SWT) desktop applications directly from a network or internet link. It offers 'one click' installation for platforms that support Java.
JWS provides many appealing features including, but not limited to, splash screens, desktop integration, file associations, automatic update (including lazy downloads and programmatic control of updates), partitioning of natives & other resource downloads by platform, architecture or Java version, configuration of run-time environment (minimum J2SE version, run-time options, RAM etc.), easy management of common resources using extensions..
Here is a demo. of the JNLP API file services (an API available to JWS apps.) that registers an interest (claims an association with) in the .zzz file-type in the launch file. Associations can also be done programmatically using the IntegrationService of the JNLP API.
I coded a Java program to read and modify a file on the computer. The program is based only on 1 class.
At the moment who want to use it has to run it from terminal, I'm looking on how to insert it on a webpage and make it run on the visitor's computer. It would be fine to have a file chooser (the user will want this modification).
I searched on internet and found Java applets, but I read that they aren't downloaded and executed locally so the program won't work.
How to provide a Java class file from a webpage, for use on the computer of the end-user?
If you really want to download a Java program and run it locally, you should check out Java Web Start.
Briefly, it allows the user to download and run a Java program locally on their machine. It does clever stuff like identify if an updated version is available for download, and will run the cached version if that's the current version.
Here's a tutorial.
..it would be fine to have a file chooser ..
In that case, there are basically the two options as I've outlined in comments throughout this question & the answers. I'll collect them together here:
Digitally sign the applet, get the user to accept the digitally signed code when prompted (before the applet is loaded), then offer a JFileChooser to browse to the file.
If the user has a plugin 2 JRE (chase the links in the JWS info. page for more details), it is possible to deliver the applet to the user unprompted, then leverage the JNLP API to produce a file chooser. The user will be prompted before the dialog appears, this time with a more specific warning.
JWS
For an example, see my applet based GIF animation tool which uses the JNLP API when the user goes to load image frames or save the animated GIF.
That applet is not open source (mostly because of my laziness in not wanting to revisit & tidy the code) but there is a much better example of using the JNLP file services that comes complete with source.
Digital signatures
I don't have any great links about the process of digitally signing code, but note that the 'example of using the JNLP file services' listed above provides one set of signed Jars for 2 different security environments. It also (hopefully obviously) demonstrates how to digitally sign code using Ant (it all happens by invoking the default task in the build.xml).
Applets can modify files locally, if they are signed and the user allows them to.
Read up on signed applets.
I read that they aren't downloaded and excuted locally
Whereever you read that, it is 100% incorrect. Applets are downloaded into the browser and executed at the client host.
I'm looking at all possible languages to solve a particular business case problem.
Basically need a way to allow user to browse for an excel file locally, then using Microsoft Excel COM automation, read in the cell contents and from this point on perform some actions.
I have no experience with Java, but I know this type of thing is "almost" possible using Silverlight 4.0. Here is a line of code that demonstates how you begin automation in silverlight using c#:
dynamic objExcel = AutomationFactory.CreateObject("Excel.Application");
Problem is Silverlight only opens files from "My Documents", and it seems there is nothing you can do to allow the app full access to the file system to read in any file. So I'm investigating if Java is capable of this task?
I don't need a big explanation on how to do it, mainly I just need your experience as a Java developer to say - Yes in principle its certainly possible, or not. I need to open this xls file from any location the user specifies.
So 2 things really:
Can you browse and open any file using a trusted java applet? And get access to the files path from the open dialog?
Can you automate MS Word / Excel from a Java applet.
Thanks
..Silverlight only opens files from "My Documents", ..
Java will not be able to break that security restriction.
It is for the benefit of the end user, in that if they truly want to edit the Excel file, they will save or move it to My Documents. If they cannot do that, then perhaps they should not be altering the file.
I need assistance finding a delivery method that best fulfills the following requirements:
We wish to deliver a single file to my clients.
Clients should be able to launch this file from the operating system shell - much like running an '.exe' on Windows.
After being launched, the program/script should be able to display a window with HTML content. this may be done using a stand alone program, a runtime or by running within a browser.
We need the ability to embed a resource within the delivered file, such as an mp3 file, which i can later extract programmatically.
Optimally, the solution should run on Windows, Mac and Linux machines. Less than perfect cross-platform interoperability is acceptable, but we want as broad a penetration as possible.
Clients should not need to pre-install anything (unless it is done transparently), pre-configure anything, or approve any thing for this to happen.
For example:
We could use a regular executable file, written in C++ to do this, but it will not be cross-platform.
We could use a sliverlight XAP file, an adobe Flex file or a Java JAR, but internet explorer warns users when local content is launched. In addition these approaches mean that we have less than perfect penetration, even though it is acceptable in these cases.
We could use a python (or equivalent) script, but the installed-base (penetration) of the python interpreter is not good enough.
Using a standard HTML is not enough because of the difficulty of embedding resources in it. Embedding Silverlight XAML or uuencoded content in HTML causes IE to display a warning.
Using something along the lines of a jpeg as a delivery method is not rich enough since we need to display HTML.
..but internet explorer warns users when local content is launched..
I don't get it, what's the problem with IE saying "Hey this app is trying to run your files!"
I don't mean you don't have a good reason for this, it is just, I don't get it.
IE will only warn the user if the app has not been downloaded and try to access local resources, for instance if running from an applet or a JNLP like this one:(click on the first orange button you see )
But if the users download the jar and run it from the computer ( double click on it ) the app is local and can run without problems.
The jar file is a zip file after all, so you can attach your mp3 file with it. Double click is supported in the desired platform, and the HTML content could be either a local file ( un-packed along with the mp3 file ) or an internet web page.
Java is preinstalled on those OS already.
"internet explorer warns users when local content is launched"
There's a reason for this. How can they distinguish your excellent, well-behaved, polite application from a virus?
Since the line between your app and a virus is very, very blurry, go with any of Silverlight XAP file, an adobe Flex file or a Java JAR.
The IE business is a good thing, not a bad thing.
You could try using the 'Jetty' application server.
This supposes there is a working java environment on the target machine.
Jetty is java servlet container but it is possible to configure
everything (web server, html templates, applications, etc.) in a
single executable jar, which launches the web server and opens a default page.
Exactly how the jar file is launched will vary from platform to platform
but otherwise the user interface will be identicle, and, as its a java application
you can do pretty much anything one it has started.
Sounds like MIME HTML does exactly what you want - unfortunately, it is not supported by many browsers other than IE.
I'd investigate Adobe AIR. It can display both HTML and Flex content in a desktop application without using a web browser. However this will require installation of the AIR runtime, also I'm not sure if the Linux version is out of the beta stage.
http://www.adobe.com/products/air/
You can also use a binary for each platform.
As per your description the app is very simple, and porting from one platf to another sounds like just matter of re-compile and offer binary based on the dist.
Is this an option?