I am learning to build Chrome extension and I have an idea to build something which requires complex computation (using many java libraries) which seems hard to be implemented by JavaScript.
A general architecture I have in mind is:
Chrome Extension (GE) extracts HTML elements and feeds HTML elements to Java application as input. Java application does the complex computation, and then feedback the results to GE. GE finally renders the results into the browser.
Does anyone know is this feasible? Does this have to involve a server architecture? Could you also refer me to some further information?
Note: It is a Java application, hopefully you can give me some Java specific answers.
Thanks in advance.
You would need to create java web application running on server (which can be accessed via URL) which you will be communicating with through ajax requests. Chrome extension (or any other js app) doesn't care what's running on server - java, php, or something else. It just sends HTTP POST/GET request to provided url and receives response back.
If you are asking if you can pack some java into your extension then the answer is no. You can pack some C++ though.
Related
I have developed a Chrome extension and it captures some data in a webpage.
My ultimate goal is to pass this final result to my Java Application.
I have following few options in my mind, but I was not able to find any resources for them yet.
Access the localStorage externally.
Run Chrome browser through the Java app, So I guess we have the control of its data.
If no API found, write the result to a file and access it from the
Java App.
Is there any API to achieve any of the first 2 options? Or any other interface other than the file system?
I checked with berkelium and The Chromium Embedded Framework. But they are just chrome wrappers, and we cannot run a chrome instance from it.
Edit
For the 2nd option I tried with Selenium Webdriver, but I think it hasn't any method to access the localStorage.
It sounds like you are looking for Native Messaging, which allows communication between a Chrome Extension and a native application (e.g. a Java Desktop Application).
There are plenty of question here on SO regarding the implementation of Native Messaging and there is, also, the "official" example.
I suggest the above solution, but if your application will heavily interact with the extension (and you feel like reverse engineering) there is the open-source **[NetBeans Connector Chrome Extension][3]**, which uses a different approach (Sockets or WebSockets - I am not sure).
Take a look at **[this answer][4]** for info on how to get at the sources.
Is there a limitation preventing you from exposing a REST API with your java application?
I would like to replace Java Applet which currently needs to use client's resources, i.e. external readers, and to communicate with a server via socket.
Reason:
1. I have thousands of client machines using this Java Applet program, and most of them are running out-dated JRE. When the Java Applet program is updated / added new features, all client machines will need updating the latest JRE.
Expected Solution:
The Java Applet program would be expected to be replaced by a web-based application, which allows to compile and run source code at client's side such that the new web-based application could still use client's resources and communicate with server via socket.
Can I use JavaScript to achieve it?
I would very appreciate your help/suggestion for this problem. Thank you!
JavaScript is a scripting language that gets evaluated in the browser.
I would not describe it as compiling and running but yes, it does mean you can run code in the client and is commonly used to create applications that run in the browser.
There's a staggering amount of frameworks that you can use to write your application. Take a look at the TodoMVC site to see the same TODO app created using several different frameworks.
If you come from Java applets, GWT may be interesting to look at.
If you wish to let the JavaScript client listen for messages from the server, take a look at websockets.
The smart card reader is going to be a problem, though!
See Architectures to access Smart Card from a generic browser? Or: How to bridge the gap from browser to PC/SC stack?
By the way:
The real issue with outdated JREs is not that your code will not run on old JREs, you can create perfectly fine applets using java 1.4 or java 5. Any libraries you may need you can deploy alongside your applet. The pain is a security problem. Anything but the latest version Java plugin is getting actively exploited and puts the user at risk. Occasionally, even the latest version is not safe.
try socket.io
I think this is the latest technology you can use to communicate with client browsers. it support the latest browsers and mobile browsers too.
hope this will help you.
Javascript has become very powerful with HTML 5.0. Here is a list of new elements that you can use to access all kinds of resources, including local files, audio, video, GPU rendering (canvas + WebGL) and GPU compute (WebCL). Here are even more things you can do, including database connections and networking. You can even create offline Javascript applications.
jQuery and jQuery layout make robust GUI development a lot easier. Rich tool suites, such as Google Closure offer optimization and a compiler for improving performance and detecting obvious mistakes early in the development process.
W3 offers useful stats for making an informed decision on how many users on average have access to which features. Note that the most annoying guy in that list arguably is IE8 due to it's lack of proper HTML 5.0 support.
In case you want to stick with Java, then one alternative would be to use my http://bck2brwsr.apidesign.org project. It's goal is to create small Java that can run in 100% of modern browsers without any plugin installed.
There are Java bindings to HTML (via knockout - one of the four most popular frameworks for HTML5) and that is why one can code whole business logic in Java and just render it via HTML. Should be enough to replace most of the applet UI.
In addition to that there is an experimental API to render on HTML canvas. People use it to write Java games that run in a pure browser.
There is a simple way to communicate with server via JSON REST API or via WebSockets. A live example is here.
I am trying to program a Thunderbird extension, in which I want to use features from certain java libs. But because the TB extension is written in pure javascript, I can't figure out the best way for these two technologies to communicate.
I was thinking about something like sending an ajax request from TB extension, catching it with java server code and then responding to it. I know how to work with ajax and mainly intrested in "java part" of this problem. I'm aware that, this can be solved by catching request with servlet, but I want to know if there is any solution with "pure" java.
Can anybody tell me if it is possible, or even show me some example code?
Writing an extension isn't just writing Javascript, you'll be dealing with Mozilla's XPCOM API. There is an active Mozilla project for using Java to communicate with this API. See here: https://developer.mozilla.org/en-US/docs/JavaXPCOM
I'm writing an application in groovy with grails that needs to do some automated usage of a couple of websites. So I need something that will perform a similar task to functional web application testing, without a browser being needed. I would also like it to be as lightweight as possible and of course completely headless.
There are two options that I am aware of so far. Canoo which has a nice grails plugin and conveniently also a firefox recorder plugin and EasyB/JWebUnit which can be recorded with Selenium.
Canoo seems very heavy and I don't know what I'd have to do to get it to run in a grails service neatly.
Perhaps I'm thinking about this wrongly though. Has anyone here done this kind of thing in Java or Groovy? Am I better off just dropping out to curl on the command line perhaps?
Have you though about just sending your web requests? Maybe you don't need a full blown headless browser and a line like
def html = new Url("http://example.com").text
is enough for your app?
A testing tool or framework is great when you have to click virtual buttons. But if you only have to remote control a website, sending a request could be enough.
Update: if you need to send POST requests and handle cookies, then the Url-Class isn't enough. But you can use the http builder instead. Here are two URLs which will get you started:
http://blog.swwomm.com/2011/01/groovy-httpbuilder-cookies.html
http://groovy.codehaus.org/modules/http-builder/doc/post.html
I want to create an application that submits same/similar data to sites containing web forms. These sites use PHP scripts...
I have a php script with me, that submits data in the manner that i require, to such forms. What I want to do is, design an entire web app around this code... I tried to obtain equivalent java code that does what the php code is doing, but could not obtain such code...
Since Google App Engine supports Quercus framework for PHP, what I am thinking now is, use the PHP code for actual submission of forms to their actions, and rest of application (that tracks all submissions and does other stuff like login/logout...) is in Java.
This would require some method by which I can pass the relevant form parameters from Java code to the PHP script, then some way for the php script to return the response of each submission back to the java code.
Is such an application doable? Pls keep in mind that I want to use Google App Engine for this purpose.
Nowadays it is possible to use different languages in different modules of the same app.
See Using both Java and Python with the new "Module" feature on AppEngine?
It should be doable with Quercus. We deploy a Python app that has some Java/Clojure backend processors but both languages are "native" to GAE. Using PHP will be a serious pain and not worth it all. I suggest that you just learn Python you will master it faster than using Quercus on GAE.
If you also go after PHP you stick to your LAMP knowledge. I suggest thay you do now!
Disclaimer: I wanted to use JRuby on AppEngine but I had a lot of difficulties (plus you have to know how everything works optimally on GAE) so I took up Python