Develop Reference

Device finger print not getting recorded in Jmeter script

I face error while scripting Credit card transaction in jmeter.
Issue seems device finger print is not getting capture (which is dynamic ) .this dynamic parameter is not generated hence script fails .signature generation algorithm generates signature but jmeter fail to capture it .

As per JMeter project main page:
JMeter is not a browser, it works at protocol level. As far as web-services and remote services are concerned, JMeter looks like a browser (or rather, multiple browsers); however JMeter does not perform all the actions supported by browsers. In particular, JMeter does not execute the Javascript found in HTML pages. Nor does it render the HTML pages as a browser does (it's possible to view the response as HTML etc., but the timings are not included in any samples, and only one sample in one thread is ever displayed at a time).
So if your fingerprint checking or signature generation algos rely on JavaScript execution in the client (browser) you won't be able to record and replay your scenario in JMeter.
The options are in:
Use a real browser, there is WebDriver Sampler which provides JMeter integration with Selenium browser automation framework, this way each thread (virtual user) will kick off a real browser and real browsers are normally capable of executing JavaScript
Replicate the logic of JavaScript in terms of fingerprint reporting or signature generation using JSR223 Test Elements and Groovy language

how to create web pages in which network requests cannot be captured by browser's debugger

This doesn't involve coding. I am just curious on how to make a page like the one described below.
I came across a website where we can attend quiz/tests.
I tried to debug the browser so that I can see if I could hack through the codes by getting the values that are getting passed in debugger.
But to my surprise the debugger is not coming up when I click F12 in that page.
Somehow I opened debugger for that page and I clicked on the Network tab to capture requests that are sent.
But as I was proceeding through the test, not even one request is getting captured in the debugger but the answers are getting validated and scores are getting updated !! I was not even able to do inspect element
I guess its a java applet as i saw the below line in the the launch button
flagPlayerCourse = true;launchApplet(secureSessionId,courseName, courseType,winParams, use508);disablePlayButton(1, 0);
the url had SinglePassUserCmd.cfm?sessionid=3xxxxx
So my question is how can we create such a webpage in which the requests are not captured in the debugger!? I would be happy if someone could tell me how do the same in asp.net. In which language can we develop such web pages!?

Applets are completely different world. Its almost as good as running a .net application on your client machine.
What you see in the debugger are ajax requests and resources loading. If a site doesn't make them, you won't see any network requests in the browser.
That doesn't mean that you can't capture the data being send. You can always use a debugging proxy like fiddler to see what traffic is going across. Ofcourse a secure site would secure their traffic over https.
Applets require a java plugin in your browser. There are similar plugins like Silverlight, flash/shockwave(swf) that too can make network requests.

how are javascript based websites different?

I am trying to scrape the content of a website which seems to be working on javascript or some other technology. I am using xpath to find the content on the page. I can see the content using firebug in the browser but if i save the source or download the source code via curl/wget, content is missing from the page. How is this possible ?
thanks in advance

Some content are loaded via JS dynamically. You need to run the JS somehow, like in a headless browser like PhantomJS for several seconds in order to load dynamic content. Then run through the DOM, similar to how .html() in jQuery does it, to get the rendered content.
As far as I know, this is similar to how Opera Mini does it in their proxies before they re-encode and send it to your device:
The server sends the response back as normal — when this is received by the Opera transcoding servers, they parse the markup and styles, execute the JavaScript, and transcode the data into Opera Binary Markup Language (OBML). This OBML data is progressively loaded by Opera Mini on the user's device.
Opera Mini's entry from Wikipedia:
JavaScript will only run for a couple of seconds on the Mini server before pausing, due to resource constraints.
According to the documentation for Opera Mini 4, before the page is sent to the mobile device, its onLoad events are fired and all scripts are allowed a maximum of two seconds to execute. The setInterval and setTimeout functions are disabled, so scripts designed to wait a certain amount of time before executing will not execute at all. After the scripts have finished or the timeout is reached, all scripts are stopped and the page is compressed and sent to the mobile device.

Typically the page loads and then requests the content (ajax) which is returned as json or jsonp. This is usually pretty handy for scraping because json is even easier to parse than html.
But if you haven't done it before, it can be a challenge to figure out how to make the right ajax request.

Open client side program using Javascript

I have created a Java program which takes some command line arguments to run. I need to make a browser extension to the program so that the program can be opened with data from the browser.
I know Javascript does not allow any local file access, but there are programs which doing the task I needed.
Examples are Internet Download Manager which has the browser extension for running it receiving command line arguments from the browser. Obviously extensions for most of the browsers including Chrome and Firefox are made using Javascript? Is there any way to do local program execution via JavaScript (I think there's a way surely)?

You can't directly run anything from your JS sandbox on client PC (just think about security risks!) There's other method however: Make your application register itself as protocol handler when it installs and use links with this protocol on your pages (think how e-mail clients serve mailto: or torrent clients serve magnet: links). Since you control both sending and receiving side, you can pass pretty much any information in those. You can find Windows example for registering a handle at MSDN. Should you need it for any other system, I'm pretty sure searching for "system_or_gui_name register protocol handler" will show you desired result among the first.

How to execute shell scripts from a web page via javascript/jquery and get its results in a string?

in a simple html file opened locally via firefox I need some javascript code to execute a command (maybe "ls") and get it's result in a string I can use in js/jquery to alter the page contents.
I already know this is a generally bad idea, but I have to make this little local html file capable of running several scripts without a server and without cgi.
In the past I've used to install a plugin in TiddlyWiki (www.tiddlywiki.com) to execute external commands (firefox requested authorization for every operation), so javascript can do it, but how to get command result in js after execution?

I don't believe there's any way to do this without a cooperating browser plug-in. The browser plug-in would be told what command to execute via javascript, it would go execute that command and then call you back with a callback when the results were available. This could be very dangerous as giving the browser access to your local system in almost anyway opens you up to lots of types of attacks (which is why browsers don't offer this capability).