GWT Application loading time - java

I am using GWT 2.0.3 with ext version.When I run the application its take some time to load.As much as I know It take time to load some JS file (Not sure about it).For slow internet connection it wiil take more time.
I want to know what exactly GWT application do while loading.If it is loading some JS file the is there ant way to reudce loading time by dividing JS file or by nay other way?
Thanks in advance

When a GWT application loads, it loads all js files contained in your html host page, what means everything client side related is loaded.
To optimize this GWT introduced code splitting some time ago. You can check it here. The basic idea is to divide your application in logical parts, when a user wants to access to another part, its loaded on demand.

To speed up web app loading time, indeed split points are a first step.
But check as well this tool:
http://pagespeed.googlelabs.com
Slowness can also come from uncompressed pictures for instance.
Also, when you compile your GWT app, ensure you use "OBFUSCATED" mode for your compiled javascript, which makes it significantly smaller.
http://code.google.com/webtoolkit/doc/1.6/FAQ_DebuggingAndCompiling.html#Why_is_my_GWT-generated_JavaScript_gibberish?
Now if you are using Apache HTTPD as web server, Google has released a wonderful Apache module that implements web app best practices out of the box:
http://code.google.com/p/modpagespeed/

Related

Problems with deployment, advice needed for a web-based java application

I have developed a command-line (read: no GUI) Java application which crunches through numbers based on a given dataset and a series of parameters; and spits out a series of HTML files as resultant reports. These reports hold a large amount of data in tables, so in order to give the users a easy and quick overview of the results, I utilized the JUNG2 library and created a nice graph.
Here's where it gets interesting; since I would like the graph to be interactive it should be deployed after the application has run and files are generated, whenever the user wants to view the reports. I decided to go with an applet based deployment, however I am not too happy with the current setup due to the following reasons:
I want to make the software as simple to use as possible (my users won't be tech-savvy, and even tech-intimidated in most cases). I would really like to distribute one JAR only, which forced me to put the applet with everything else it needs in a package in the same JAR as the main application.
The applet and the main application need to communicate the results, so I create a xML-based report which is used to hold information. As long as the files are on a local machine and are not moved around it all works fine. Unfortunately I also need the files to be moved around. A user should be able to take the "results" folder to a USB stick, go anywhere plug the stick to another computer and be able to use the report as he/she likes.
For the time being the applets are implemented with the following html code:
<applet code="package.myapp.visualization.GraphApplet.class"
codebase="file:/home/user/myApp"
archive="myApp-0.2.6-r28.jar"
width="750" height="750">
<param name=input value="results/test_name/results.fxml">
</applet>
As you can see this applet will not work if the parent folder is moved to another location.
As far as I know I have a couple of alternatives:
a) Change codebase to point to an URL on our webserver where I could put the jar file. This however creates the problem with permissions, as the applet will not be able to read the results file. Alternative is to upload the results file to the server when the user wants to visualize the graph, although I am not sure if that's a good option due to server security and also if it could be made so that upload happens automatically without bothering the user.
b) I can use a relative path on the codebase attribute, but then the whole folder hierarchy needs to be intact upon copy. This could be a last resort, if I cant come up with a better way to do it.
c) change the deployment method (would like to avoid this alternative to not spend more time on the development phase)
Any ideas? Am I missing something? How could I tackle this problem?
Thanks,
I'm not sure I entirely understand your use-case, but from what I do understand, I would suggest this:
Dump the applet for an application launched using Java Web Start. Have the JNLP file declare a file association for the fxml file type. When the user double clicks an fxml file, it will be passed as an argument to the main(String[]) of the JWS application.
A sand-boxed JWS application can gain access to resources on the local file system using the JNLP API. Here is my demo. of the JNLP API file services.

Upload large files with browsers without having it hanging (preferably with flash)

I am trying to upload a lot of files from a browser to a webserver that I have total control of. I've tried to use SWFUpload, but the problem is that my browser hangs when I am uploading a file. The files are supposed to be of any length (up to 2GB due to other restrictions, of course).
While the upload is in progress the browser hangs and the GUI is not updated. When the file is finally uploaded the GUI responds again. In firefox the entire browser stalls and in Chrome just the tab.
I thought it might have something to do with flash trying to inject the entire file in to the memory first, but that does not seem to be the case (although different test cases yielded different results, but I'm not sure that it's because of that reason).
An applet is also an option, although flash is preferred. The reason I don't want to use a form is because you can select multiple in flash (also possible with Java, I assume) which is a nice feature that I'm going for.
Any ideas? Thought?
(math|tob)ias
If you're using linux, this is a known problem. For Windows users this doesn't happen. Otherwise, you'll have to stick to ajax (the best way is with the jQuery forms plugin).
http://www.plupload.com/, this one looks interesting, but I haven't looked into it. You may want to give it a try.
Try an AJAX one:
http://sourceforge.net/projects/uber-uploader/
Lighter on the resources and more platform-independent.
client-side I like this jquery plugin:
http://valums.com/ajax-upload/
if you need examples of server-side handling:
http://php.net/manual/en/features.file-upload.php
I've use this for my projects... http://jupload.sourceforge.net/ I found I had better results though when I used it in FTP mode. I had issues with http uploads. It does support multiple files which is nice. You can upload the files into an "incoming directory" and then process them later when the transfer is finished.
Check SWFUpload swfupload.org
and there is a descussion about this point:
http://swfupload.org/forum/generaldiscussion/173

Best way to upload multiple files from a browser

I'm working on a web application. There is one place where the user can upload files with the HTTP protocol. There is a choice between the classic HTML file upload control and a Java applet to upload the files.
The classic HTML file upload isn't great because you can only select one file at a time, and it's quite hard to get any progress indication during the actual upload (I finally got it using a timer refreshing a progress indicator with data fetched from the server via an AJAX call). The advantage: it's always working.
With the Java applet I can do more things: select multiple files at once (even a folder), compress the files, get a real progress bar, drag'n'drop files on the applet, etc...
BUT there are a few drawbacks:
it's a nightmare to get it to work properly on Mac Safari and Mac Firefox (Thanks Liveconnect)
the UI isn't exactly the native UI and some people notice that
the applet isn't as responsive as it should (could be my fault, but everything looks ok to me)
there are bugs in the Java UrlConnection class with HTTPS, so I use the Apache common HTTP client to do the actual HTTP upload. It's quite big a package and slows down the download of the .jar file
the Apache common HTTP client has sometimes trouble going through proxies
the Java runtime is quite big
I've been maintaining this Java applet for a while but now I'm fed up with all the drawbacks, and considering writing/buying a completely new component to upload theses files.
Question
If you had the following requirements:
upload multiple files easily from a browser, through HTTP or HTTPS
compress the files to reduce the upload time
upload should work on any platform, with native UI
must be able to upload huge files, up to 2gb at least
you have carte blanche on the technology
What technology/compontent would you use?
Edit :
Drag'n'Drop of files on the component would be a great plus.
It looks like there are a lot of issues related to bugs with the Flash Player (swfupload known issues). Proper Mac support and upload through proxies with authentication are options I can not do without. This would probably rule out all Flash-based options :-( .
I rule out all HTML/Javascript-only options because you can't select more than one file at a time with the classic HTML control. It's a pain to click n-times the "browse" button when you want to select multiple files in a folder.
I implemented something very recently in Silverlight.
Basically uses HttpWebRequest to send a chunk of data to a GenericHandler.
On the first post, 4KB of data is sent. On the 2nd chunk, I send another 4K chunk.
When the 2nd chunk is received, I calculate the round trip it took between first and 2nd chunk and so now
the 3rd chunk when sent will know to increase speed.
Using this method I can upload files of ANY size and I can resume.
Each post I send along this info:
[PARAMETERS]
[FILEDATA]
Here, parameters contain the following:
[Chunk #]
[Filename]
[Session ID]
After each chunk is received, I send a response back to my Silverlight saying how fast it took so that it can now send a larger
chunk.
Hard to put my explaination without code but that's basically how I did it.
At some point I will put together a quick writeup on how I did this.
I've never used it with files of 2GB in size, but the YUI File Uploader worked pretty well on a previous project. You may also be interested in this jQuery Plugin.
That said, I still think the Java Applet is the way to go. I think you'll end up with less portability and UI issues than you expect and Drag/Drop works great. For the record, Box.net uses a Java Applet for their multi-file quick uploads.
OK this is my take on this
I did some testing with swfupload, and I have my previous experience with Java, and my conclusion is that whatever technology is used there is no perfect solution to do uploads on the browser : you'll always end up with bugs when uploading huge files, going through proxies, with ssl, etc...
BUT :
a flash uploader (a la swfupload) is really lightweight, doesn't need authorization from the user and has a native interface which is REALLY cool, me thinks
a java uploader needs authorization but you can do whatever you want with the files selected by the user (aka compression if needed), and drag and drop works well. Be prepared for some epic bugs debuggin' though.
I didn't get a change to play with Silverlight as long as I'd like maybe that's the real answer, though the technology is still quite young so ... I'll edit this post if I get a chance to fiddle a bit with Silverlight
Thanks for all the answers !!
There are a number of free flash components that exist with nice multiple file upload capability. They make use of ActionScripts FileReference class with a PHP (or whatever) receiver on the server side. Some have recently broken with the launch of FP10 but I know for certain that swfupload will work :)
Hope this helps!
What about these two
Jupload
http://jupload.sourceforge.net/
and
jumploader
http://jumploader.com/
Both are java applets but they are also both really easy to use and implement.
what about google gears?
There are HTTP/HTTPS upload controls that allow multi-file upload. Here is one from Telerik, which I have found to be solid and reliable. The latest version looks to have most if not all of your feature requirements.
You can upload multiple files with HTTP forms as well, as Dave already pointed out, but if you're set on using something beyond what HTTP and Javascript offers I would heavily consider Flash. There are even some pre-existing solutions for it such as MultiPowUpload and it offers many of the features you're looking for. It's also easier to obtain progress information using a Flash client than with AJAX calls from Javascript since you have a little more flexibility.
You may check the Apache Commons FileUpload package. It allows you to upload multiple files, monitor the progress of the upload, and more. You can find more information here:
http://commons.apache.org/fileupload/
http://commons.apache.org/fileupload/using.html
Good luck

Java Applets loading at snail's pace

I have a Java Applet application ( achart) on my php Webpage ... Problem here is the Java Applet takes more time to load ... I am thinking of replacing these applets with some similar technology but fast ... I am counting on Ajax... what are my other options ... ?
Java applets load slowly. shrug Its the nature of the beast....
If you have multiple jars, you should check the order of the classpath you provide to your applet. Note that each jar is only downloaded "on demand" whenever a class needs to be loaded. It looks in the first jar, if it can't find the class it looks in the second and so on... You can reduce your startup time by ensuring that all of your classes required for starting up the app are in the first jar(s) listed.
Also, if you are attempting to load a class or resource which is not in your classpath, it must search through all the jars before returning AND hit the server codebase to look there. It can potentially greatly reduce your startup time.
Turn on applet tracing in the java control panel and you should get a better idea of how classes are being loaded out of the jars.
If the size of the applet's JAR library takes to long to download, you can shrink the size with the ProGuard tool. Here is a comparison of the compression ratio for some Java libraries.
Have you packed your jars.....
Have you tried Java deployment toolkit (http://blogs.oracle.com/vaibhav/entry/java_deployment_toolkit_6u10)
with jdk 1.6.10+.....
If its simple charts you want, have a look at:
http://code.google.com/apis/chart/
Yahoo has some nice charting components for actionscript 3 (flash) http://developer.yahoo.com/flash/astra-flash/charts/
Google has a service that will generate charts as images as Tim already pointed out.
Alternatively you could try to speed up the delivery of the applets that you are using - check if they have an Expires header so they only get downloaded once in a while instead of for every page (this won't help on the first view, but will speed up those after that)
Edit: if you only target specific browsers you could try and create the charts using javascript and the Canvas element, but that is definitely not supported by internet explorer. https://developer.mozilla.org/en/Canvas_tutorial
I know this answer is a bit late but, it could be that you are just being very inefficent with java or your machine is slow, I have a java program that has quite alot of code as well as accessing an SQLite DataBase and it runs quite quickly, loading within five seconds. If you have anything you don't use in your program then remove it, also try jaring and signing it(not sure if last two things would help.)

Cross-platform executable/runtime delivery method

I need assistance finding a delivery method that best fulfills the following requirements:
We wish to deliver a single file to my clients.
Clients should be able to launch this file from the operating system shell - much like running an '.exe' on Windows.
After being launched, the program/script should be able to display a window with HTML content. this may be done using a stand alone program, a runtime or by running within a browser.
We need the ability to embed a resource within the delivered file, such as an mp3 file, which i can later extract programmatically.
Optimally, the solution should run on Windows, Mac and Linux machines. Less than perfect cross-platform interoperability is acceptable, but we want as broad a penetration as possible.
Clients should not need to pre-install anything (unless it is done transparently), pre-configure anything, or approve any thing for this to happen.
For example:
We could use a regular executable file, written in C++ to do this, but it will not be cross-platform.
We could use a sliverlight XAP file, an adobe Flex file or a Java JAR, but internet explorer warns users when local content is launched. In addition these approaches mean that we have less than perfect penetration, even though it is acceptable in these cases.
We could use a python (or equivalent) script, but the installed-base (penetration) of the python interpreter is not good enough.
Using a standard HTML is not enough because of the difficulty of embedding resources in it. Embedding Silverlight XAML or uuencoded content in HTML causes IE to display a warning.
Using something along the lines of a jpeg as a delivery method is not rich enough since we need to display HTML.
..but internet explorer warns users when local content is launched..
I don't get it, what's the problem with IE saying "Hey this app is trying to run your files!"
I don't mean you don't have a good reason for this, it is just, I don't get it.
IE will only warn the user if the app has not been downloaded and try to access local resources, for instance if running from an applet or a JNLP like this one:(click on the first orange button you see )
But if the users download the jar and run it from the computer ( double click on it ) the app is local and can run without problems.
The jar file is a zip file after all, so you can attach your mp3 file with it. Double click is supported in the desired platform, and the HTML content could be either a local file ( un-packed along with the mp3 file ) or an internet web page.
Java is preinstalled on those OS already.
"internet explorer warns users when local content is launched"
There's a reason for this. How can they distinguish your excellent, well-behaved, polite application from a virus?
Since the line between your app and a virus is very, very blurry, go with any of Silverlight XAP file, an adobe Flex file or a Java JAR.
The IE business is a good thing, not a bad thing.
You could try using the 'Jetty' application server.
This supposes there is a working java environment on the target machine.
Jetty is java servlet container but it is possible to configure
everything (web server, html templates, applications, etc.) in a
single executable jar, which launches the web server and opens a default page.
Exactly how the jar file is launched will vary from platform to platform
but otherwise the user interface will be identicle, and, as its a java application
you can do pretty much anything one it has started.
Sounds like MIME HTML does exactly what you want - unfortunately, it is not supported by many browsers other than IE.
I'd investigate Adobe AIR. It can display both HTML and Flex content in a desktop application without using a web browser. However this will require installation of the AIR runtime, also I'm not sure if the Linux version is out of the beta stage.
http://www.adobe.com/products/air/
You can also use a binary for each platform.
As per your description the app is very simple, and porting from one platf to another sounds like just matter of re-compile and offer binary based on the dist.
Is this an option?

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