I want to run a third-party application from gwt for manipulating a local file and after this send file to server. I released the feature for uploading and sending file to server, but between these steps I want to change something in this file (with 3-rd party application installed on client machine). The main problem is that the applet cannot be used because nor Chrome, nor Mozilla do not support it. Are there some examples of other tools and technologies to do this?
The FileReader and FileWriter api can be used to work with local files. I think the htmt5rocks has a good example of how this can be done with javascript. These processes can be used with GWT elemental FileReader and Writer. I've added links to the javadoc below.
http://www.html5rocks.com/en/tutorials/file/dndfiles/
http://docs.sencha.com/gxt/4.x/javadoc/gwt-2.7.0/index.html?elemental/html/FileReader.html
http://docs.sencha.com/gxt/4.x/javadoc/gwt-2.7.0/index.html?elemental/html/FileWriter.html
Answer is simple: GWT is client-side technology. You cannot run 3rd party application installed on client side, access local drive files or so.
If you want to change some local file fromt GWT application, then you need to expose Java Applet, do operation on server side and then process it.
Why are you saying Firefox and Chrome don't support it?
Related
I need to show to a user an interface of some application running on a server using a browser. It should be like RDP-client for a single application on a server.
Are there any solutions or services that can implement following functionality? Maybe Citrix?
Thanks in advance!
This looks like what you're looking for:
http://freerdp.net/
About FreeRDP-WebConnect
FreeRDP-WebConnect is an open source gateway for accessing RDP
sessions using any HTML5 compliant browser. In particular it relies on
the Canvas and the WebSockets feature. FreeRDP-WebConnect is a
subproject of the FreeRDP project.
On the server side, a standalone daemon - written in C++ - provides a
Web page via HTTPS (or HTTP, if configured) and uses FreeRDP libs to
connect as a client to any RDP session. The server side WebSockets
implementation handles current RFC6455 only, so browsers that
implement the older drafts do not work. With RFC6455 being raised to
the "Proposed Standard" level, this should change now really soon.
I would create an account on the server for the user, and only give it access to the one application it needs access to.
You can use Cameyo. To start, create yourself a free account, and click on "Add App". If your installer supports unattended installation, you simply need to submit it. Otherwise, you can build a Cameyo package locally and send it in. It will then be playable as HTML5.
You don't indicate what server you are running on.
As an alternative to FreeRDP-Webconnect cited above, also open source and also using FreeRDP as rdp client through an HTTP gateway, there is Myrtille.
FreeRDP-WebConnect embeds a standalone daemon written in C++ to provide a web page via HTTP(S), and so will also work on Linux servers, while Myrtille have a IIS/.NET (C#) implementation and an MSI installer, thus is more intended for Windows Servers.
I'm having trouble wrapping my head around how to use servlets properly
I've set up a postgres database, and downloaded a JDBC driver for it.
What I want to have is my webpages post to the servlet, and the servlet get info from the database. I understand how to code everything (eg add library for driver, open connections, execute queries), but I think I'm lacking knowledge in how to set up the file structure.
I have the postgresql database running on pgAdmin. Do I also need to have a server running to make the servlets work as well? Can't I just make a web.xml file that maps to the servlets, and open the webpages to use the website? If I run the project through an IDE with a server running (glassfish) everything works. If I close the IDE and go to open the webpages on my browser again, I get 404's whenever I submit to a servlet.
Can someone give me a bit of guidance on the big picture of how everything is supposed to interact (with details on servers please). I've been searching the web and I havent found anything that explains the big picture very well.
Thanks
A Java web application is a set of files obeying a well-defined structure, and which can be packaged in a war file.
This web application is deployed into a server (also called container), which understands the file structure, listens to HTTP requests, and calls the appropriate servlet of the appropriate deployed web application when it receives one.
And of course, if you shut down the server, nothing listens to the HTTP requests anymore, so you won't get any response.
You could read the Java EE tutorial for more explanations.
I'm building a web app with Backbone.js (I'm not tied to Backbone yet though). I need a back-end framework only for persistence to a database via a RESTful API. However, I also need to able to deploy it as a 'desktop' app for off-line use, i.e. running a local server and launching a browser window, but I don't want users to have to start a server from the command line to run the application.
I can use SQLite as a database since it's only a single user application, it's just the framework that I'm stuck on. I have looked at the following:
Rails and Django: Default web servers are too flimsy, requires Ruby/Python and runs from the command line. I'm aware of the Bitnami stacks but at 99mb it's too big of a dependency and not exactly hidden from the user.
Sproutcore: Run from command line, also too bulky.
Pyjamas Desktop - Depends on MSHTML which I suspect limits my ability to use HTML5 features.
I'm leaning towards creating a Java app that starts a Scala/Lift server instance and opens a web browser, then sits in the system tray (kind of like WAMP). Is anyone familiar with a tool or framework built for user-friendly deployment as a standalone desktop app?
I do not know if PHP is an option for you? Then I would recommend phpdock.
web2py has a standalone deploy-to-desktop feature with no dependency on Python: http://web2py.com/books/default/chapter/29/14#How-to-distribute-your-applications-as-binaries
As Eydun said, phpdock is an option but it's commercially licensed .
I settled on using Java/Spring/H2/Hibernate/Jetty. I find that Jetty serves requests VERY quickly so the application looks real-time when launched in a browser. There is a tutorial on embedding the Jetty server here. I imagine it's quite trivial to build a GUI that launches the server and a browser.
Another Java option is to use the Play Framework, which may be more at home to those coming from a Django/Rails background. However, the documentation for "creating a standalone version of your application" for Play 2.0+ indicates that they have ditched using Java EE containers (Tomcat/Jetty) and WAR files in favor of running the JARs with the bundled copy of JBoss Netty, so it may take a bit of work to get it running the way you want it.
I would recommend the Play Framework approach if you're OK with using/learning Scala.
I think answer on my question is NO. But still, I'm wondering is it possible to run gwt applicaton as frontend for example on Apache HTTPD server. The idea that compiled gwt is pure javascript and don't need java backend (if we don't use java based RPC)
There's nothing stopping you. GWT code breaks down into two parts; server-side and client-side code. As you say the client-side code compiles down into pure javascript which can be easily served up by httpd.
The main advantage of using gwt's classes on the server is that data you request via RPC will arrive in your client code as java objects with no work on your part. But you can easily make calls to any old service using the RequestBuilder class, or XMLHttpRequest if you need more control.
Edit: There is one special bit of configuration you should do to make sure httpd works well with your client-side gwt code:
<Files *.nocache.*>
ExpiresDefault "access"
</Files>
<Files *.cache.*>
ExpiresDefault "now plus 6 months"
</Files>
This makes sure that when you upload a new version of the app users' browsers will download it automatically, but also makes sure that they won't download the entire app every time they visit your website. Very useful.
Your opinion is wrong. You can create a gwt application which is designed only for front-end.
To test that you can do the following
Create a sample gwt application which has only front end content
Compile and build the application
Place the build content folder in your Apache web directory.
Ee : if you created a project called test-gwt, the JS and HTML contents are in test-gwt directory created inside the war directory.
Access the new application through a web browser, like http://localhost/test-gwt
Hope this would help.
That is possible and works like a charm as long as you don't write your server component with gwt.
Here is an simple gwt client only htaccess password app (currently only german) as an example, wich i've coded for fun.
"I'm wondering is it possible to run gwt applicaton as frontend for example on Apache HTTPD server".
The answer is NO. GWT UI frontend does not run on any server at all. It runs only on a browser with Javascript enabled.
But if I ignore the language semantics of the question and answering the gist of it - the answer is Yes. Pardon me, but I think the language you should have written is
"is it possible to SERVE the gwt applicaton frontend from an Apache HTTPD server".
Just deploy your servlet-less war onto the HTTPD (removing the WEB-INF folder).
In fact, you could even write RequestBuilder requests to request for static json streams from files placed in the GWT module development "public" folder. Where the GWT compiler would copy the contents of the "public" folder to the deployed application root.
Or you could use script-include to get your GWT client request for dynamic content jsonp from another server - which would not create any servlet in your app. I documented the script-include technique here: http://h2g2java.blessedgeek.com/2011/06/gwt-requestbuilder-vs-rpc-vs-script.html.
I have a J2EE application that runs fine and is accessible to the internet. Some of our prospective customers would like to use it, but are unwilling to send their data over the internet.
As a workaround I've thought of providing them with the war file and letting them run it themselves.
The problem is: how do I make it trivial for them to update the application when I make a new version available? The more difficult it is, the less likely they are to buy in.
What's involved in writing an updater that fetches the latest war file from online and updates the web application? Is this even possible?
In the least they would need to redeploy the war file. Most application servers have an interface through which you can upload a new war file. I am in favor of doing this process manually i.e. you send them a war file and they can use the app server's admin page to deploy the new war. This way they explicitly know when they are updating the app. Also they control when they want to deploy a new version of the app and easily roll back to an older version.
I would recommend using Jetty as an embedded solution. I have used a few apps that that use the embeded functionality. It allows you to create a packaged distribution of your application that runs a servlet container out of the box.