how can I let an SWF file to retrieve values immediately from Java application that does live calculations (Speed is a necessity).
question in other form : how can I
give my website browser immediate data
- that are bean calculated now - as fast as i
can ?
I'm going to assume the calculations are being done in a Java applet in the same browser where the flash is running.
You can call Javascript from within the applet using the following code. This code could then update the values in the flash animation.
import netscape.javascript.JSObject;
JSObject win = JSObject.getWindow(applet);
win.eval("window.alert('Hello from Java')");
If my assumption is incorrect, then where is the Java application running? On the client or server?
If it's on the server then you need Flash remoting. I believe there are a few different Flash remoting techniques. Try searching for java flash remoting. You can make it call the server every 2 seconds or so to get the latest data.
If it's running on the client I doubt you can connect to it from Flash because of security. A signed Java applet could connect anywhere it wants to. You could retrieve the data using it, then push it into Flash using the method described above. Would be a crazy hack though. Can you do the same thing with Flex? (I've never used Flex before).
If the speed is crucial, you would probably want to do it via some kind of socket connection. Usually signed applet or a WebStart Java application is able to open a listening socket. Flash application then would be able to connect to this socket and as a result you will have very fast bidirectional communication.
There are some caveats however.
You should bear in mind that user might get suspicious about weird socket activity on his machine, or it would be just blocked by a firewall - so you'll need to warn user.
In order to be able to connect from Flash to Java, you must dispatch crossdomain policy file from the listening socket (or any other below 1024 - see documentation for details; keywords: crossdomain, policy-file-request, loadPolicyFile). Also your Flash application might need to request such file manually from the Java application.
Couple of useful links on how to get certificate for your Java application: how to get free code signing certificate (Russian), similar but less detailed description in English.
However, if you are able (read: the speed is sufficient) to use Java Applet <-> JavaScript <-> Flash combination I'd advice to take advantage of it.
Related
I'm facing a problem nowadays with my home router. I want to write a small application that will ensure the router will stop/switch off if no packets transmitted in last 30 minutes. Is there a way to do?
Precisely, I want to switch off my router/start it back through a Java program, desperately looking for some suggestion from some experienced coder.
Any help would be welcome.
Thanks
I guess the answer is that it depends on which router you have and what kind of interface it provides for controlling it.
My own router has no API that I know of which allows it to be directly accessed via a Java program (although yours might be different).
My router does have a web interface and can be accessed over HTTP. Conceivably by making the right post request I would be able to power off my router. I imagine you might find that yours is similar.
EDIT (added text)
To use the web interface you need to first find the IP of the webserver - probably 192.168.1.1 or 192.168.1.254 . Type this into your browser to get the control panel and find the button that turns off the router. Press this button with the network tab open in the developer tools (if you're not sure what this means use google) and capture the url it uses.
Now you have the IP and the request you can mimic this and send the same request directly using your Java code. Again to find out how look online. For example Sending HTTP POST Request In Java
END EDIT
The other problem you have is monitoring traffic to and from your router. You can do this a number of ways. Off the top of my head I would suggest using a raw socket to listen for all traffic and monitor everything that goes across the web interface of the device running your Java program. Alternatively you can use an existing solution like TCPDump which will do the same.
The question you have asked is very broad with a number of reasonable answers - it is also a kind of big question - so I have tried to provide some reasonable thoughts to get you started rather than actually write the code for you.
Hope this helps.
I am working in a web application using ASP.net and C#.
My target is to check on a desktop application on the client machine .. If it was exist then I should launch it. Else if it wasn't exist, we should download, install and then launch it.
I could develop this module using Java Applet but unfortunately, Google decided to disable NPAPI in September 2015, So the applet will not working on Chrome.
My question is about the Applet alternatives to help me implementing the above scenario ?
The only (semi) viable option as far as I can see, is to offer the Chrome user a link to a JNLP file for a desktop application. Then when/if the JWS desktop application starts, have it report back to the server 'loaded OK' and then 'target app. installed/not installed'.
On your server, have a time out for waiting on the client to report back. If it passes that time, presume the client machine does not support Java at all and the user is checking some web service to try and figure out what app. opens a JNLP!
After searching about the most suitable way to achieve my goal, I think using custom protocols will be a nice solution to access my client applications from the web page.
This solution is used by many companies such as Microsoft (using mailto: to open Outlook application) and Apple (using itms: to open iTunes application).
The following link is a very good link which talk about a custom protocols:
https://support.shotgunsoftware.com/entries/86754-How-to-launch-external-applications-using-custom-protocols-rock-instead-of-http-
Once Google Chrome was the first to announce that they won’t be supporting NPAPI anymore, they were also the first to provide a new architecture in order to rewrite your code to work on their browser. You can take a look on Native Messaging, which “can exchange messages with native applications using an API that is similar to the other message passing APIs”. The problem is that this approach only works on Chrome, is not something that you can adapt to other browsers.
A more useful approach is FireBreath, a browser plugin in a post NPAPI world. Check the words below from one buddy of the project:
“FireBreath 2 will allow you to write a plugin that works in NPAPI, ActiveX, or through Native Messaging; it’s getting close to ready to go into beta. It doesn’t have any kind of real drawing support, but would work for what you describe. The install process is a bit of a pain, but it works. The FireWyrm protocol that the native messaging component uses could be used with any connection that allows passing text data; it should be possible to make it work with js-ctypes on firefox or plausibly WEB-RTC or even CORS AJAX in some way. For now the only thing we needed to solve was Chrome, but we did it in a way that should be pretty portable to other technologies.”
Now, I have some problems here:
I looked several times in Google and so on, but I can't find an "easy" way to get this done. And currently having a migraine... not helping me... though
I have a java eclipse program (Swing application to be a "controller" for production-machines).
I need to design an Android app, which needs to take data from the eclipse program in a wireless network (and also send them back).
Just found solutions like JPARSON or setting up a real server, but that is way too complicated... i don´t need?! (or want :D ) to set up a whole website with php or something...
Can someone of you help me out with a better solution? It doesn't need to be code-specific, I just want to exchange like 10 strings for these machines.
If you want to exchange data you need a communication medium. The easiest way to do this is via TCP/IP protocol suite. If you decide on having a Server-Client architecture, your serwer has to listen for what phones have to say. He can do this by listening on specified port and you would have to handle "protocol", or you can use somewhat easier approach which is to write php script, or Java Servlet. PHP script is easier becaouse there is like a gazzilion php hosting providers and it's cheap. If you would like to write your own serwer, you wold need some sort of Virtual Private Server, and deploy your app there. Plus it would be helpfull if you explained a little more your environment and what you are trying to achive.
There's built in httpserver http://docs.oracle.com/javase/6/docs/jre/api/net/httpserver/spec/index.html so you can easily implement a simple webservice in standalone java. Then just use URLConnection from android to post/get data, probably in json or your own format.
I want to make a multiplayer Android game and am an absolute novice at anything and everything networking. I have some knowledge of socket programming in C and Java, however from what I understand, it is not that simple when communicating from an Android device to a remote server. Basically, I am just unsure of how to go about setting up server-side components of this project. I've been told to look into frameworks, but am not really sure exactly how they would be used in my particular case.
Here is a breakdown of how my application works and how I want it to communicate to the server. The client application will send a request to the server whenever a user wants to login, create game, make a move, check statistics, etc. The server will update or retrieve information from a database(somehow) and send it to the client. If the player is to make a move, the server is responsible for doing all calculations, storing the gamestate, and pushing the updated game to both players.
I was hoping somebody could shed some light on how I would go about starting this. Any information would be greatly appreciated. Thanks
Essentially you want to set up a Socket Server program listening on your server for connections from the client. You can achieve this through any number of ways, but it seems like you are going to want to tap into a database (such as MySQL) running server side in order to handle authentication of users logging in, etc. Since you say you have familiarity with Java already, and Android is Java based, I would suggest you go with Java for the server application. A few things to look into to get started would be:
Socket Programming in Java:
http://docs.oracle.com/javase/tutorial/networking/sockets/index.html
Chat Client/Server Examples in Java here:
http://pirate.shu.edu/~wachsmut/Teaching/CSAS2214/Virtual/Lectures/chat-client-server.html
Also look into Java JDBC tutorials on Oracle's website (for interfacing Java with a MySQL server), and you will likely find that Android AsyncTask class will come in handy when you implement your Android client. It might be better to start with a pure Java client to get the server aspect working first and then move to an Android-based client. Once you establish some code you can make more refined posts here and gather more specific answers. Hope that helps and good luck.
I wish to control my computer (and usb devices attached to the computer) at home with any computer that is connected to the internet. The computer at home must have a program installed that receives commands from any other computer that is connected to the internet. I thought it would be best if I do this with a web interface as it would not be necessary to install software on that computer. For obvious reasons it would require log in details.
Extra details: The main part of the project is actually a device that I will develop that connects to the computer's usb port. Sorry if it was a bit vague in my original question. This device will perform simple functions such as turning lights on etc. At first I will just attempt to switch the lights remotely using the internet. Later on I will add commands that can control certain aspects of the computer such as the music player. I think doing a full remote desktop connection to control my device is therefore not quite necessary. Does anybody know of any open source projects that can perform these functions?
So basically the problem is sending encrypted commands from a web interface to my computer at home. What would be the best method to achieve this and what programming languages should I use? I know Java, Python and C quite well, but have very little experience with web applications, such as Javascript and PHP.
I have looked at web chat examples as it is sort of similar concept to what I wish to achieve, except the text can be replaced with commands. Is this a viable solution or are there better alternatives?
Thank you
VNC
SSH
Remote Desktop (Windows)
You can write a WEB APPLICATION. The encryption part is solved by simple HTTPS usage. On the server side (your home computer with USB devices attached to it) you should use Python (since you're quite experienced with it) and a Python Web Framework you want (I.E. Django).
While it is an interesting programming question, perhaps you should ask it on ServerFault instead? There you can probably get a lot of nice input on web-based administration / control tools.
Unless this is a "for fun" project for you, there are about a jillion things out there that already do this. And if you want to control a computer from a web browser, be prepared to require installing some kind of custom plugin - since browsers can't touch arbitrary files on the local filesystem, execute local applications, or do other things that are flagrant security risks.
I've been using VNC for over a decade - free and easy.
http://en.wikipedia.org/wiki/Virtual_Network_Computing
Well, I think that java can work well, in fact you have to deal with system calls to manage usb devices and things like that (and as far as I know, PHP is not the best language to do this). Also shouldn't be so hard to create a basic server/client program, just use good encryption mechanism to not show commands around web.
I you are looking for solution you could use from any computer anywhere in the worls without the need to install any software on client pc, try logmein.com (http://secure.logmein.com).
It is free, reliable, works in any modern browser, you don't have to remmeber IPs and hope they won't change, ...
Or if this is a "for fun project" why not write a php script, open port 80 in your router so you can access you script from outside, possibly dynamically link some domain to your IP (http://www.dyndns.com/). In the script you would just login and then for example type the orders in textfield in some form in your script. Lets just say you want to do some command prompt stuf, so you will basically remotely construst a *.bat file for example. Then the script stores this a fromtheinternets.bat to a folder on your desktop that is being constantly monitored for changes. And when such a change is found you just activate the bat file.
Insecure? Yes (It could be made secureER)
Fun to write? Definitely
PS: I am new here, hope it's not "illegal" to post link to actual services, instead of wiki lists. This is by no means and advertisement, I am just a happy user. :)