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)
Related
I'm using IntelliJ IDEA, I have coded a frame which I want to put into an HTML file so I can run it in my browser, how do I do this now that I cannot use JApplet? I have found this documentation: http://docs.oracle.com/javase/tutorial/deployment/webstart/deploying.html and this http://docs.oracle.com/javase/tutorial/deployment/webstart/deploying.html but I am new to programming and find this difficult to follow. I don't know for instance how I would go about putting my class files and the image that I used in a separate directory nor do I know how I go about signing my application so that it will run in a browser.
I want to put into an HTML file so I can run it in my browser,
You can use the Desktop class. This class allows you to access default applications from your desktop.
Read the section from the Swing tutorial o How to Integrate With the Desktop class for more information and working examples.
See Java Plugin support deprecated and Moving to a Plugin-Free Web.
Note that is one of my 'copy/paste comments' that does not explicitly mention JFrame based apps., however the links are still relevant in that Oracle & browser makers would not be phasing out support for applets if they wanted programmers to keep trying to shove rich client apps (e.g. Swing GUIs) into thin client web pages.
OTOH you can offer a JFrame (or a JApplet) to be launched from a link in a web page to end up free floating on the desktop of the user by using Java Web Start.
Even then, it is not a simple matter for the programmer or the end user. The programmer needs to ensure the app is digitally signed using a code signing certificate issued by a CA (usually they are expensive). The end user used to just be able to click the link, 'OK' the prompts produced by the Java virtual machine, and see the app appear on-screen. But now most browsers will download the launch file to the local file system rather than directly hand it to the JVM to be launched. So the user faces an extra step in explicitly finding the downloaded launch file and double clicking it.
This is all due to security concerns related to bugs in the plug-ins that run things in web pages. So if you were to find a way around all these hoops, please let us know. It is a security bug that requires urgent fixing.
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."
How can I execute a desktop application from a browser?. I have a web page with a button, when user click this button a simple java desktop application must run. How can I do this using jsp or javascript?
Java Web Start might be your solution.
To start a Java Web Start application, you simply direct the browser to the location of the JNLP file. Basically, the browser detects that instead of simply downloading the file, it should run it in Web Start.
Most major browsers support Java Web Start. Java Web Start is cross platform (works on Mac and PC).
So, in Javascript, it's done simply like this:
window.location = "http://www.examples.com/myapp.jnlp";
You'll also need to sign your Java application, or the user will get a nasty warning.
You should take a look at the Java Web Start technology.
This would be the closest thing: Java Web Start
Managing this through Applets is another option though the underlying scheme is the same, the user needs to accept the generated certificate.
I was reading about java web start from wiki. Can someone please tell me
What is it used for?
A practical application of it; to make its use clearer.
Do other languages like C++ / C# have
anything similar?
Thanks,
Roger
Java Web Start is kind of like a successor to applets - it allows Java programs to be run from your browser (though unlike applets, they don't run within the browser). For a practical example, see the TopCoder Arena.
http://www.topcoder.com/contest/arena/ContestAppletProd.jnlp
Here, Java Network Launching Protocol (JNLP) is the protocol that defines how a Web Start application should be run (analogous to HTML telling a browser how a page should be rendered).
See the Oracle tutorials:
Lesson: Web Start
Deploying a Java Web Start Application
Java Network Launch Protocol
Java Web Start software provides the
power to launch full-featured
applications with a single click.
Users can download and launch
applications, such as a complete
spreadsheet program or an Internet
chat client, without going through
lengthy installation procedures.
With Java Web Start software, users
can launch a Java application by
clicking a link in a web page. The
link points to a Java Network Launch
Protocol (JNLP) file, which instructs
Java Web Start software to download,
cache, and run the application.
I'm quoting the Java Tutorial lesson on WebStart
For those of you who work with .Net something like Java Webstart is ClickOnce technology.
Java Web Start is used to write sandboxed desktop applications similar to Java Applets. Like applets they can be launched from a web browser, but they run in their own window - not inside the browser.
It runs just like a normal application, but started from clicking a web page instead of having to download and run an installer. An advantage is that it's very easy to get people who are afraid of all the security warnings to try your application. Another advantage is that you don't need to keep the browser open while you run your application. You can even install a shortcut to your application onto the user's desktop so they don't need to touch the browser at all once they have run it the first time.
The .NET equivalent is Click Once.
What is it used for?
To roll out and keep updated an application to clients. Clients need "only" a Java Runtime installed. This may be more interesting to read.
Java webstart is used to deploy/install Java applications over the network.
The alternative is to send an application (MyApp.jar) to the users who will run that directly. But if it is out-of-date, they could have collisions when the application talks to the server (for example, or other such badness).
It also allows you to package all of the required libraries. This is a HUGE benefit.
http://java.sun.com/javase/technologies/desktop/javawebstart/index.jsp
As mentioned above, it's a technology to allow you to 'push' an always up to date Java app to users. It's not often used on a consumer level, but has some adoption in a corporate atmosphere.
It's best used in somewhat controlled environments, and is especially useful to push a specific version of client software to control a server.
Do other languages like C++ / C# have anything similar?
Yes. Microsoft provides something called ClickOnce that provides a web-based installer.
Today i am looking for the same example about the Java web start...
I thing this link will work for you,i have used as a beginner.
Click Here
As mention With Java Web Start software, users can launch a Java application by clicking a link in a web page. The link points to a Java Network Launch Protocol (JNLP) file, which instructs Java Web Start software to download, cache, and run the application.
We had a project, a plugin for Protégé, which is an ontology editor.
Installing the plugin isn't that hard, but to give the user a quick impression how the plugin worked, we supplied a Java Web Start application on our site. The page is still active, the plugin may have some rough edges, since it hasn't been updated for a while ... http://dac.icore.at/one/solutions.
I'm currently not aware of similar products for C/++/#.
Java web start is the 0-install solution in the java world.
An application built to use Java web start (JWS) will be available as a link in a web site. This site will have the .jnlp extension.
When a user clicks this link (and clicks the "execute" button of his browser) , the javaws.exe runtime will be launched. This executable will download the application and dependencies (libraries, images, and so on) and launch the application using the provided main-class of the .jnlp file).
An extensive reference of JNLP content can be found at http://lopica.sourceforge.net/ref.html
Examples of Java web start applications can be found at Swing sightings.
Notice that, depending upon the chosen configuration, these applciations can also be automatically installed in start menu.
Is it feasible to launch an application via a browser / URL? What are the options for doing this?
I know the way to do it with IE and Windows (which usually doesn't work). Ideally, I would like this to be browser independent.
Our application is RCP, so in theory Java Web Start could work, we would just have to do some significant changes to how we deliver our application to users, which I would like to avoid. Our web server code is currently all Java if that makes a difference.
I pretty much gave up on this until I clicked a url on Apple's site, which in turn launched iTunes.
How does Apple do that?
iTunes registers itself as a protocol handler for custom itms:// and itmss:// protocols. When you hit a URL with that protocol - after a step of indirection on Apple's web servers, in this case - iTunes launches to handle it, much like your browser launches to handle http:// URLs or your email program launches to handle mailto: URLs.
This isn't "cross-platform", per se, but it does work on every platform out there, as URL handlers exist and do the same thing everywhere.
It has the disadvantage of only working if the application is already installed, which is why you may want to have a splash page that instructs people to install the application if necessary.
Silverlight 3 and Adobe Air will let you launch applications outside the browser.
If this is OS independent, then you can't rely on any specific program being available. What kind of program would you want to launch anyway?