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How do I run Java apps in Mint?

Posted: Tue Apr 30, 2013 11:53 am
by SirFalcon
Using Mint 14 MATE 64 I can not run any java applets. They seem to load up then nothing happens and firefox stops working right. If I close firefox it will not reopen and claims that it is already running. I have to kill it in the system monitor then it will run again. How do I get Java to work correctly?

P.s I tried searching the forums but you can't search four letter words like "java", "JDK", or "ice tea".

Re: How do I run Java apps in Mint?

Posted: Wed May 01, 2013 7:34 am
by karlchen
Hello, SirFalcon.

I always use this Oracle website for testing whether the current Java plugin has been installed correctly: How do I test whether Java is working on my computer?
This webpage will tell you whether a Java plugin has been installed and activated at all.
Provided your Java software and the corresponding Java brwoser plugin have been installed correctly, this website will tell you which version you are using and whether a newer version is available (on the Oracle site, not necessarily in the Linux repos)

So by visiting the webpage How do I test whether Java is working on my computer? you can find out pretty quickly whether your Java and your Java browser plugin function properly.

Kind regards,
Karl
--
Java plugin working all right ...
Image
(Java Plugin OK and up-to-date)

Java plugin de-activated in Firefox ...
Image
((Java Plugin de-activated)

Re: How do I run Java apps in Mint?

Posted: Wed May 01, 2013 7:41 am
by catweazel
Just the way I like it...
Something is wrong. Java is not working.
Beastly thing it is. It's only good for launching exploits.

:mrgreen:

Re: How do I run Java apps in Mint?

Posted: Wed May 01, 2013 7:51 am
by karlchen
Hi, catweazel.

Correct, Java plugins are insecure, maybe by design. Yet, this was not the question.
The question is how to make them work correctly.
Once they do you can still turn them off.
Sometimes this is not an option, in most cases when you have to use software that depends on them.

Anyway, as a first step I just wanted to explain how anybody can find out easily whether they can run Java applets in their browsers.

Cheers,
Karl

Re: How do I run Java apps in Mint?

Posted: Wed May 01, 2013 12:34 pm
by karlchen
Hello, SirFalcon.

About your question:
How do I get Java to work correctly?
Shutdown any open brwoser instance. Launch Synaptic Package Manager and make sure that you have exactly the list of software packages installed which you will see in the screenshot below (click the image in order to enlarge it).
These should be all openJDK packages and icedtea browser plugin packages which are required to make openJDK 1.7.0 work and the matching browser plugin.

HTH,
Karl
--
Image
(Synaptic - openJDK and icedtea browser plugin. The list has been photographed on Mint 13, but it is the same on Mint 14)

Re: How do I run Java apps in Mint?

Posted: Wed May 01, 2013 4:36 pm
by catweazel
karlchen wrote:Hi, catweazel.

Correct, Java plugins are insecure, maybe by design. Yet, this was not the question.
The question is how to make them work correctly.
So? Are you suggesting I can't express an opinion on the general subject?

Re: How do I run Java apps in Mint?

Posted: Wed May 01, 2013 5:56 pm
by SirFalcon
I looked in the package manager and I do have all of the highlighted packages installed. I went to the link to test if java is working correctly, and it is! But its not. I am trying to run the Jmonkey demo applet at http://jmonkeyengine.com/demo/applet/. It loads up but I get no applet. Same thing happens if I try to run runescape.
Maybe there is a problem with my graphics card driver or something else that involves OpenGL. I have a Radeon HD 4350, using what ever driver Mint supplied for it.

Re: How do I run Java apps in Mint?

Posted: Sat May 04, 2013 5:01 am
by karlchen
catweazel wrote:So? Are you suggesting I can't express an opinion on the general subject?
Yes, you can and you have done so. :wink: And I expressed my agreement on the point you made.
Yet, SirFalcon wants to make the insecure Java (plugin) work in his browser. Maybe he really needs it.
Karl

Re: How do I run Java apps in Mint?

Posted: Sat May 04, 2013 5:17 am
by karlchen
Hello, SirFalcon.
SirFalcon wrote:I went to the link to test if java is working correctly, and it is! But its not.
Yes, it is. If Oracle states that your Java (plugin) is fine then it is. :wink:

Foolishly I activated my Java plugin and visited this page: http://jmonkeyengine.com/demo/applet/
I had to confirm 2 dialogues similar to the one in the screenshot below asking whether I wanted to allow a Java applet to run. I confirmed by clicking the [RUN] button twice.
(Double foolish, because Java warned me that the certificates were expired and could not be verified as being genuine.)
And then all I got was the initial page telling me something about OpenGL 2.0 being required and that the applet should work. But it did not run.
I guess your second assumption may be right. Some problem with the graphics driver software.

You are using an ATI card, me, I am using NVidia and proprietary Nvidia drivers.

Code: Select all

 $ inxi -Gx
Graphics:  Card: NVIDIA ION VGA bus-ID: 03:00.0 
           X.Org: 1.11.3 drivers: nvidia (unloaded: fbdev,vesa,nouveau) Resolution: 1280x1024@60.0hz 
           GLX Renderer: ION/integrated/SSE2 GLX Version: 3.3.0 NVIDIA 304.88 Direct Rendering: Yes
Looks as if this might not be good enough. But maybe, too, by blaming our graphics drivers we are on the totally wrong track now?

Before we start fiddling around with our graphics drivers - which I definitely will not do - we might take into consideration that the webpage / the applet does not really co-operate with Java 1.7.0_21? - As soon as I have got the chance I will try with Java 1.6.0_45, which has been installed on a different machine and which is needed there for some software that does not run on Java 1.7.0_21.

<Added 18:00>
No, Intel graphics card plus Java 1.6.0_45 does not seem to be right, either.
Hm, I suspect the OpenGL version which we will find on Ubuntu 12.04.2/Mint 13 is not up-to-date enough, correct?

Code: Select all

glxinfo | grep "OpenGL version"
OpenGL version string: 1.4 Mesa 8.0.4his might explain why the Java applet will not display anything.
1.4 < 2.0. And this indeed brings us back to the graphics driver software.
</Added 18:00>

So final verdict for the moment:
It is not a Java problem, but a question of your OpenGL version. So, please, run the commandline

Code: Select all

glxinfo | grep "OpenGL version"
If the version string is anything lower than 2.0, you have identified the root cause why the Java applet refuses to run.

Kind regards,
Karl
--
Image
(Confirm JAVA applet start)

Re: How do I run Java apps in Mint?

Posted: Sun May 05, 2013 8:21 am
by SirFalcon
I replaced my tired Ati card with an Nvidia GTX 650 Ti.
The applet still does not run. It runs fine in windows though.
I downloaded and installed the linux drivers from nvidia (with much difficulty) and now
I have other issues. At any rate, if I check the GL version is says:

OpenGL version string: 4.3.0 NVIDIA 319.17

Thanks for your research and input.

Re: How do I run Java apps in Mint?

Posted: Mon May 06, 2013 8:57 am
by karlchen
Hello, SirFalcon.

Not that it will help you much, but the OpenGL version is the crucial factor:

Code: Select all

~$ inxi -Gx
Graphics:  Card: Intel Mobile 4 Series Chipset Integrated Graphics Controller bus-ID: 00:02.0 
           X.Org: 1.11.3 drivers: intel (unloaded: fbdev,vesa) Resolution: 1680x1050@59.9hz 
           GLX Renderer: Mesa DRI Mobile IntelĀ® GM45 Express Chipset x86/MMX/SSE2 GLX Version: 2.1 Mesa 8.0.4 Direct Rendering: Yes
~$ glxinfo | grep -i "opengl version string"
OpenGL version string: 2.1 Mesa 8.0.4
This is a really weak internal Intel graphics card, but the open source driver brings along OpenGL 2.1.

Image
(Java Applet Demo with Open GL 2.1)

Too bad that the official NVidia-current driver software (304.88) only supports OpenGL 1.4 and that NVidia 319.17 causes trouble on your system. Yet, I'd keep an eye on bug reports and bug fixes for the 319 driver series. There might be a bug-fixed version sooner or later.

Kind regards,
Karl