I have a web page where sometimes I need to communicate with a device.
This device is accessed with sockets, so I have a jar file with the support libraries.
When you want to get data from the device, you press a button, and a javascript method fetches the data using the library (no java code here)
The presence of the jar makes the java machine to start as soon as you load the page.
Since there is a lot of users that don't use this option (usually they don't even have the device, to begin with), they see that as a nuisance.
Is there a posibility to delay the java loading until the button is pressed ?
I don't want to redirect them to another page, that should be done in the same page.
You can load the jar file into a seperate div created dynamically via javascript, at the time you need it.
If you want to consider loading your application with java-webstart-technology, you can implement a button similiar to what oracle has on their page here
Basically what the button does is download the required jars specified in a jnlp-file and launch it.
Related
I'm trying to build a report-building tool (which has a UI written in JavaFX) that has the following features:
When the system (re-)boots, it should auto-start in the background (without showing the UI)
It should have an icon in the system tray
The UI should only show when the user clicks on the system tray icon
A report should be generated either once a day/week/month, at a specific time, automatically
It should "snooze/sleep" in the interim period and use minimal resources while it awaits the next trigger time
It should show a toast pop-up / Windows notification / whatever when a new report has been generated
(The bold ones are the real problems, the italics are maybe solvable--given some resources I found--and the un-formatted one I have a work-around for, namely to place it on in the Startup folder in the AppData folder of the users' machine.)
But the clincher is the following: due to my company's policies, I'm NOT allowed to build register it as a Windows service. Also, converting it into a web service, placing it on a server, and using Control-M (or a cron expression) are also off the table. (That's a long story for another day.) I'm not sure how to implement it and I've been stuck on this for a bit.
I've taken a look at Quartz, this other StackOverflow question, and some other resources on how to run the Java app in the background, but most resources tell me to add it as a Windows service and I keep hitting a brick wall. Also, I don't know how much of an effect the application would have on the users' machines if I ran the application in the background with the solutions mentioned in the other StackOverflow answer. I need to have a minimal processing footprint in the interim period.
I'm also unsure of how to package the application as an EXE. For now, I'm going to turn it into an executable JAR. (Any help on this would also be welcome.)
I'm open to any suggestions and ideas and even other resources to look at for further reading. Anything to help me out here is welcome.
In my web application I need to launch a Windows application installed on client machine when a button in the page is clicked.
I know there are security policies in browsers that avoid this by default, but I also know application that do this. An example could be online meeting, web conferencing applications like WebEx or GoToMeeting.
How they do that?
I'm working with Java, so I'm wondering if Java Applets are an option to achieve this.
Is there some other well known way to solve this issue?
NOTE application execution MUST be allowed by user
The best way to deploy a Java desktop application is using Java Web Start.
And forget applets. Soon Chrome won't be able to load them (along with a number of other plug-ins) at all.
you can achieve it with applet. but user must allow to run it. it is hard to run some extern application from button or link because this is potentially danger behaviour. Remember the applet can not get access to the files on user computer and other servers (unless it is digitally signed)
I've been pondering over this problem most the afternoon and haven't yet found the most ideal solution so thought I would see what others think..
There is a legacy Win16 application that has to be modified (with the least effort) in order to communicate with a web based application.
The idea is such that in the Win16 app, the user will want to look up a specific code, so they'll click a button which will then launch the browser and allow them to navigate a specific set of pages until they find the result they desire, then they have the option of either pressing Select or Cancel.
Pressing Select should pass back a small string back to the app (around 10 characters) and close the browser. Cancel will likewise send a Cancel message back to the app and again close the browser window.
I can't see many choices available in implementation as the Win16 app is not able to call webservices, so I'm looking at using the clipboard, however that is not without problems.
I hope there's some other alternative I haven't thought of,
As always - all advice appreciated.
Thanks,
I have blackberry app (java). My app stores some informations in files (file:///store/home/user/app_name/). When user removes app, these files don't delete.
I want to delete files when app is removed by user.
What is solution?
Don't store files this way - use Persistable for your app data instead: http://docs.blackberry.com/en/developers/deliverables/17952/Storing_objects_persistently_1219782_11.jsp
There are two "standard" ways to uninstall an application. The first, via Options - Applications menu. And the second, via javaloader -erase -f command.
Theoretically you can intercept the uninstall event for the first way (when you use "Options - Applications" menu), but you need additional application that receives this event and does the cleanup action.
To intercept and recognize an unknown event I do the following.
I write a simple BlackBerry app, that implements and uses GlobalEventListener and runs in background, and prints every intercepted global event guid to the system output and/or log with timestamps.
Now, uninstall your app from Options menu and inspect logged global event guids. After that install/uninstall another applications. And then inspect log/system output window to find out which events are related to uninstall action.
It does not guarantee 100% result, but at least you will get fun with coding, logging and exploring.
I have a simple java applet that retrieves an image from a server and prints it out. The only problem is that I get the following java security warning:
Researching on this site and all over the web, some people suggest that I sign the applet (I tried that to no avail) and others suggest that I Modify a local java security setting but that isn't feasible for my clients.
Not only do I get this warning at the start of my applet, but seemingly any time the code attempts to interact with the printer, the dialog re-appears. Also, note that there is no checkbox next to 'Always allow this applet to access the printer'. These symptoms show on any browser.
How do I get java to respect the users choice to allow it to send jobs to the printer?
You might use the JNLP API services in a sand-boxed applet in a plug-in 2 JRE. They will still prompt the user each first time they go to print, but should also put an 'always allow' check-box on the dialog (though it really only applies for that run). See a demo. of the PrintService.
See also the applet info. page that includes a link on the Next Generation in Applet Java Plug-in Technology which "..brings new abilities to applets: such as .. allowing embedded applets to gain full access to the services of Java Web Start."