My question is in two parts:
1-From applet point of view, does it differ to write an applet to work with mobile NFC? if so, what are the differences?
2-what changes are required (I mean Global Platform environment) to be done in order to communicate with the applet using mobile NFC?
My Target is to write an applet and access it using Single Wire Protocol (SWP) of mobile connected to NFC antenna. Is there any previously done project I can learn from? Where is the point to begin this?
Related
Is that possible for a javacard applet to download and install another applet?
Is that possible for an applet to send APDUs (information) to another applet?
If so, can anyone lead me to proper documentations to begin?
Is that possible for a javacard applet to download and install another applet?
No, that's not possible, there is simply no API for it. In all the examples from Global Platform - which is probably more relevant than the Java Card specifications - the applet data is loaded through APDU commands. There is an Applet.install method in the Java Card API of course, but it gets called by the system and cannot be used from another applet - not even a security domain, as far as I know.
Is that possible for an applet to send APDUs (information) to another applet?
Yes, you can have one class implement the Shareable interface and share it through the getShareableInterfaceObject method. All Java Card tutorials will include this.
The APDU buffer cannot be shared, but it doesn't need to, you can simply access it through the APDU methods. From the API:
The Java Card runtime environment designates the APDU object as a temporary Java Card runtime environment Entry Point Object (See Runtime Environment Specification, Java Card Platform, Classic Edition, section 6.2.1 for details). A temporary Java Card runtime environment Entry Point Object can be accessed from any applet context. References to these temporary objects cannot be stored in class variables or instance variables or array components.
Please do read tutorials or buy the old but still valid Java Card technology for Smart Cards. It's old, but the core principles are still completely valid, and most other basic things can be learned by studying the API.
We have a GWT application specifically designed to handle mobile clients and built with MGWT.
Now, we need to build a frontend for classical web clients, probably building it with GWT-Bootstrap and I'm wondering what's the best solution to achieve this.
How should we proceed with modules, gwt.xml configuration, client type detection, etc ...
What are your suggestions ?
Check this question for how to tell what platform the user is on.
Beyond that, GWT uses only HTML and Javascript, so unlike Flash applications, it actually works fine on mobile devices too; most events (such as clicks) are translated by the browser, so a touch becomes a click, you don't need a separate handler or anything.
Basically what I would suggest is you have a single GWT regardless of platform, and only for certain Widgets, add separate options for Mobile and Desktop, as necessary.
I don't know the architecture of your app and if you use the MVP pattern but GWTP with its Form-factors feature allows you to share almost all of your business logic (your presenters) across the different platforms. You have just to write the view depending on the platform you want to support.
We're planning on creating a feedreader as a windows desktop- and iPad application. As we want to be able to show Websites AND to run (our own) JavaScript in this application, we thought about delivering the application as HTML/CSS/JavaScript, just wrapped by some .NET control or a Cocoa Touch webbrowser component. So the task at hand is to find out which framework to use to create the HTML/CSS/JS files to embed in the application.
For the development of the HTML/CSS/JavaScript we would be happy to use Vaadin, GWT, or some other framework, as we're a lot better with Java than with JS. We favor Vaadin after a short brainstorming, as the UI components are very nice, but I fear that most of the heavy lifting will be on the server and not in the client (and that wouldn't be too nice). We would also like GWT, but the Java-to-JS compiling takes a lot of time and an extra step, and slowed down development time in the past when using it.
The question is: which development framework would you choose (given you wanted to implement this project and you mostly did Java so far) and why? If there are better framework options (List of Rich Client Frameworks), please let me know.
Edit: The application will need to talk to our server from time to time (sync what has been read for example), but mainly should get the xml feeds itself. Therefore I hope that most of the generated code can be embedded in the application and there doesn't need to be heavy activity with our server.
Edit2: We (realistically even if you doubt) expect at least 10000 users.
Based on my experience with Vaadin, I'd go for that, but your requirements are somewhat favoring pure-GWT instead.
Vaadin needs the server and server connection. If building mostly offline desktop application, this can be solved with an embedded Jetty for example. (synchronize with an online service only when needed), but for iPad you would need to connect online right away to start the Vaadin application.
GWT runs completely at the client-side and you can build a JavaScript browser application that only connects when needed.
Because Vaadin is much quicker to develop, you could build a small Vaadin version first and see if that is actually problem on the iPad.
On the other hand, if you can assume going online right away, you can skip the local server installation altogether. Just run the application online and implement the desktop version using operating systems default browser control (i.e. the .NET control you suggested). Then Vaadin is easier.
Vaadin is just framework base on GWT but have two very important features:
don't need to run GWT compiler. It is pure java. Of course if not add addons because then gwt compiler must run.
you don't need to write communication code. So you don't need to solve DTO problems, non-serializable object mappings and dont need to write servlets.
I use Vaadin in my work for one year and we haven't performance problems yet (desktop like application with ~500 users). IMO very good solution is to use Vaadin just for UI, logic move to independent beans and connect this two elements using Spring or Guice.
In this case you should use MVP pattern and Domain Driven Development.
Bussines beans is domain objects and logic that use view interfaces to send responses.
Custom Vaadin components (could extends standard components) implements view interfaces.
That way is good when you decide to change UI engine if Vaadin is not for you. Just rewrite guice/spring mappings and write new implementations of view interfaces.
My 3 cents:
If you decide to use vaadin, You will benefit from already GOOD LOOKING components. Since you dont want to write (alot of) CSS , vaadin is already good looking out of the box. How ever, Vaadin is a SERVERSIDE framework. User interface interactions will hit the back end even if they dont involve getting any data (e.g moving from one tab to the other) .
If you decide to use GWT, you will have to atleast style the application (this is not hard) . There is also the problem of long compilation time (but you can test and debug on hosted mode which allows you to run the application without compiling , then you compile only when deploying). The main advantage of gwt is that you control what gets sent to the wire, For UI interactions that dont require getting data from the backend, it will work purely on the client side. You the developer will determine when to send a request to the back end. (Doing RPC requests in GWT is very easy)
Hope this will help you make the decision.
I am working on a GWT app that needs to serve a different layout to mobile device users. I can easily determine if a user is using a mobile browser; however, I'm not sure about the best pattern for handling them.
I am currently using the MVP pattern - would it be best to simply pass a browser-specific view to the Presenter or is there a more appropriate method?
You could set up GWT to detect the web browser used, as described in this question. Then, via Deferred Binding, let the compiler "slip" the correct view into place for the, say, mobilesafari user agent. That way, you won't have to litter your Java code with browser detection, etc.
The way I've done it is to have different GWT modules (with their own entrypoint, Gin modules, even different CssResources) and then on the myapp.html page you just have to check out what browser is requesting the content and based on it (javascript checks) the appropriate module
<script src="myapp/myapp.nocache.js"/>
or
<script src="mymobileapp/mymobileapp.nocache.js"/>
is loaded.
If you are working with GIN and an MVP framework (gwt-platform is my platform of choice) you can then reuse the code that was already written for the presenters and only implement different views.
I am developing an application in GWT which needs to call a native C++ code in Directshow to do some multimedia processing.I am guessing that I cant use JNI because GWT converts code to javascript.I did have a look at similar posts on the forum(and on GWT site about JSNI) but cant find a example that specifically talks about calling C++ code from GWT(its mostly about calling Java code from Javascript).Can anyone throw some light on this or direct me to a tutorial?
Where exactly is this code supposed run? Surely not on the client-side. Client-side native code is nowhere near mass adoption.
GWT can either interface with JSNI in order to write native JS code inside your GWT Java code, or to interface with Java back-ends, whilst the framework handles the RPC. Even without GWT you have no way to run native code from within the browser (at least in the near future).
Bottom line - if you can't do it in plain vanilla Javascript on the client side, you can't do it in GWT.
What you can do is use this native code in the back-end, and call it via classic JNI from your Java back-end classes (and then what difference does it make if it's part of a GWT project or not?), but it sounds like this is not the case.
First of all, have a clear separation of Client (HTML / Javascript running in the browser) and server components (java service servlets).
If I understood your problem statement right, You need the UI to collect parameters for your transcoders and your transcoders need to run on a Windows box.
You can look up any simple GWT application to figure out how to serve a GWT application in any container (perhaps jetty for the time being) and process basic HTML form inputs. Once you have all the parameters on the server, you need to figure out how to delegate these parameters posted from the browser (your GWT application) from the service servlet (running within a web server) to your DirectShow application. This point onwards its a java application talking to a native process problem.
You can use various ways to communicate parameters to your native directshow application. Simplest solution is to initiate the application with the exec method passing command parameters inline. Otherwise you can communicate to a running native application via TCP sockets or integrate the native app using JNI. It all depends on your architectural design, which approach you wish to take.