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Applet works on Windows, Ubuntu and Mac, but not on Redhat and Fedora

Bhaskar Edgaonkar
Greenhorn

Joined: Oct 17, 2008
Posts: 4
Hi,

I am having an applet which uses AWT and has a functionality of opening up a web page dynamically. The applet also has its own menu bar. This functionality works fine on Windows, Mac and Ubuntu client machines, but the menu bar goes away when I open the web page using same functionality on Redhat 5 and Fedora 9 client machines. Moreover I am also getting an InterruptedThread exception on these machines.

For security reasons I cannot share the code. Please guide me to resolve this issue.

Thanks,
Bhaskar.
Peter Johnson
author
Bartender

Joined: May 14, 2008
Posts: 5772
    
    7

Please tell us which browser you are using, and what JVM. Based on the information you have given so far, I have to assume that you did not install either a Sun JVM or OpenJVM, and instead only the Gnu JVM.

What I assume happened is that in Ubuntu, for example, the OpenJVM was installed and properly registered applet support. But in Redhat/Fedora to Gnu JVM was installed and it did not register applet support in whatever browser you are using.

And one more thing - are these all 32-bit OSes? Because the rules change if you go to a 64-bit OS.
[ October 19, 2008: Message edited by: Peter Johnson ]

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Pat Farrell
Rancher

Joined: Aug 11, 2007
Posts: 4634
    
    5

Can I ask a more basic question:

Why, in 2008 are you trying to use an applet?
Bhaskar Edgaonkar
Greenhorn

Joined: Oct 17, 2008
Posts: 4
I am using Mozilla Firefox 3 and all my client machines are using Sun JVM and are 32 bit OSs.

This issue is not reproduced when I use Opera on Redhat and Fedora.
Bhaskar Edgaonkar
Greenhorn

Joined: Oct 17, 2008
Posts: 4
Peter,
I am using Mozilla Firefox 3 and all my client machines are using Sun JVM and are 32 bit OSs.

This issue is not reproduced when I use Opera on Redhat and Fedora.

Originally posted by Peter Johnson:
Please tell us which browser you are using, and what JVM. Based on the information you have given so far, I have to assume that you did not install either a Sun JVM or OpenJVM, and instead only the Gnu JVM.

What I assume happened is that in Ubuntu, for example, the OpenJVM was installed and properly registered applet support. But in Redhat/Fedora to Gnu JVM was installed and it did not register applet support in whatever browser you are using.

And one more thing - are these all 32-bit OSes? Because the rules change if you go to a 64-bit OS.

[ October 19, 2008: Message edited by: Peter Johnson ]
Jesper de Jong
Java Cowboy
Saloon Keeper

Joined: Aug 16, 2005
Posts: 13868
    
  10

Make sure that you are really using the Java version that you think you are using on Redhat and Fedora, and check if the correct Java browser plug-in is installed.

Also check the bug databases of Redhat and Fedora to see if there is any known issue with this. Are you for example using desktop effects stuff such as Compiz on these computers? As far as I know there were some issues with Compiz and Java GUIs (Swing) where you would sometimes get only grey rectangles. I don't remember exactly but I think some of this was solved in one of the later Sun Java 6 updates. So check if you really have the latest Sun Java 6 version on your client computers.


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Bhaskar Edgaonkar
Greenhorn

Joined: Oct 17, 2008
Posts: 4
Jesper,
I am using Java 1.6.0_07 on my machines. The pug-in is also correct. Compiz is not used.

Originally posted by Jesper Young:
Make sure that you are really using the Java version that you think you are using on Redhat and Fedora, and check if the correct Java browser plug-in is installed.

Also check the bug databases of Redhat and Fedora to see if there is any known issue with this. Are you for example using desktop effects stuff such as Compiz on these computers? As far as I know there were some issues with Compiz and Java GUIs (Swing) where you would sometimes get only grey rectangles. I don't remember exactly but I think some of this was solved in one of the later Sun Java 6 updates. So check if you really have the latest Sun Java 6 version on your client computers.
Tim Holloway
Saloon Keeper

Joined: Jun 25, 2001
Posts: 15629
    
  15

Originally posted by Pat Farrell:
Can I ask a more basic question:

Why, in 2008 are you trying to use an applet?


Well, hopefully in 2009, they're finally come out with a way of running applets that doesn't require downloading and installing scores of megabytes worth of JRE. Or at least, since we're talking Linux/Unix here, a decent JRE will now get bundled into the OS.

Applets do have their uses. I can run applets on my 64-bit machine, albeit with a kludge. I can't do that with Flash. They're more flexible and less contorted than JavaScript. You can do heavy-duty client-side computing and smooth interactive graphics without having to learn yet another programming language. They have a fine-grained security environment with a fairly good record of not being compromised.

And - in my case - because that's how the original design worked and what they're paying me for is to upgrade the applets!


Customer surveys are for companies who didn't pay proper attention to begin with.
Jesper de Jong
Java Cowboy
Saloon Keeper

Joined: Aug 16, 2005
Posts: 13868
    
  10

Originally posted by Tim Holloway:
I can run applets on my 64-bit machine, albeit with a kludge. I can't do that with Flash.

You can't run Flash? What Linux version are you using? There's a thing called nspluginwrapper which makes it possible to run the 32-bit Flash plugin in 64-bit Firefox. On 64-bit Ubuntu, this is installed for you automatically if you install the Flash plugin.

Bhaskar, did you check the Red Hat / Fedora bug databases, or ask your question in a forum specific to those Linux distros?
Peter Johnson
author
Bartender

Joined: May 14, 2008
Posts: 5772
    
    7

Bhaskar, I assume that you have followed these steps to manually install the Java plugin into Firefox:

http://java.com/en/download/linux_manual.jsp?locale=en&host=java.com

How did you install Firefox? Did you use yum or did you get Firefox from firefox.com? If you used yum, could you try installing Firefox from firefox.org, configuring the Java plugin, and trying again? If that works, you at least know the issue is with RedHat's distribution of Firefox.
Pat Farrell
Rancher

Joined: Aug 11, 2007
Posts: 4634
    
    5

Originally posted by Tim Holloway:
Well, hopefully in 2009, they're finally come out with a way of running applets that doesn't require downloading and installing scores of megabytes worth of JRE. Or at least, since we're talking Linux/Unix here, a decent JRE will now get bundled into the OS.


Not too likely. Applets are Java, they need a JRE. So if the user doesn't have a JRE, you gotta download and install it.

Clearly if the PHB pays, you gotta write. But I gave up on them, at least a decade ago
Jesper de Jong
Java Cowboy
Saloon Keeper

Joined: Aug 16, 2005
Posts: 13868
    
  10

Pat, haven't you heard about Java 6 Update 10 and the modular JRE?

Sun is working hard to make the JRE modular, so that it's just as quick and easy to install as for example Adobe's Flash plugin. The idea is that you just need to download and install the core part of the JRE. Other parts that an applet might need would then be downloaded and installed only when necessary.

Sun does this (and Java FX) because then want to compete against Flash.
Ernest Friedman-Hill
author and iconoclast
Marshal

Joined: Jul 08, 2003
Posts: 24166
    
  30

There's also this little thing called an intranet, where the network is very fast and all the desktops are controlled by one IT department so that things like JVMs are pushed out to everybody. Perhaps you've heard of them. Applets work quite well in such an environment!


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subject: Applet works on Windows, Ubuntu and Mac, but not on Redhat and Fedora
 
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