What is "java web start" used for? - java

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.

Related

Java GUI unable to automatically run on website

I have a Java program that runs a GUI that receives required information from the user/displays information. There is a button in the GUI that generates a Proposal in the form of a PDF that I wish the user to be able to download. I am having trouble having the GUI automatically run when the web page is opened, instead it just displays the icon of the JNLP file being referenced within the HTML.
Java Web Start does not run a GUI within a web page. Java Web Start is a technology for downloading and launching a local Java app on a JVM already present on the user’s machine.
Java Web Start has been phased out by Oracle, as Oracle no longer expects user machines to have a JVM pre-installed. See Oracle white paper, Java Client Roadmap Update.
OpenWebStart is an alternative open-source implementation of Java Web Start technology.
If you want to build a web app GUI using pure Java without having to learn HTML, JavaScript, DOM, WebSockets, etc., I suggest Vaadin Flow.

Java - Make a java program run on a webpage

Does anyone know how I can make a java program run on a webpage? I know many browsers now days do not support Java for security risk, but say I was using an older Java version like Java 6.
What would I have to do to get it to run on a webpage? Of course saying "Allow" or "Run Program" whenever the user clicks a button is alright. I cannot use Javascript for this.
Thank you
Another option, apart from Applets, is Java Web Start:
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.
If you are planning to do something very CPU consuming is better to use Java Web Start. But if you need some JavaScript And Java interaction it would be better to use the old Applets.
If you are worried about browsers blocking or not supporting Java Applets, then Java Web Start is again a better option.
The following links may be of interest to you:
Java Web Start (Jnlp) Hello World Example
Java SE 6: Migrating Applets to Java Web Start Applications
These things are called Applets. They are considered to be a bit old technology but they are still used at some places.
You can find a tutorial here

Launch an application on button click from a web page

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)

how to provide update services to java application?

I am working on a java application, my requirement is to provide online product update services to application. What should I do?
Take a look at Java Web Start - the software gets updated automatically, and that's handled by the web start client. You just have to provide the update.
With Java Web Start, you launch applications simply by clicking on a Web page link. If the application is not present on your computer, Java Web Start automatically downloads all necessary files. It then caches the files on your computer so the application is always ready to be relaunched anytime you want—either from an icon on your desktop or from the browser link. And no matter which method you use to launch the application, the most current version of the application is always presented to you.

Execute application from web browser?

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.

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