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Java 7 - ejs applet does not work with it - Jul 17, 2013 at 5:34PM
Julia Branke
11 Posts

Hello,

some ejs applets that worked fine for me in the past do not run with Java 7.

Did anybody experience similar problems?

Thank you,

Julia


Replies to Java 7 - ejs applet does not work with it

Re: Java 7 - ejs applet does not work with it - Aug 10 2013 4:39AM
Francisco Esquembre
138 Posts

Julia,

For a reason I ignore, my MacOS computer refuses to load applets from the hard disk. But it loads them if served from a HTTP server.

If you are running on a Mac, that may be the problem. I don't know what happens on Windows.

If the applet does not rung even when served by a server (and it was generated with EJS), please ZIP it and put it here, and I'll have a closer look.

Paco



Re: Re: Java 7 - ejs applet does not work with it - Aug 12 2013 10:13AM
Julia Branke
11 Posts

Dear Paco,

thank you for your reply,

I did some further tests after I posted the question and found out, that Java 7 is not the sole reason for my problem.

My ejs applet does actually run on MacOS X with Java 7.

It does not run as an applet on some Windows 7 Java 7 machines I tried, which lead me to post that I have a problem with Java 7, since my main computer does not have Java 7 installed.

But if I put the simulation as an application on those Windows 7 Java 7 machines the application runs fine, so Java 7 within the browser is a problem, and there the tightened security might be at the root of problems.

I did some reading and it seems the Java is forcing security at rapid rates. If I interpreted things correctly in some futher version, selfsigned applets will be strongly discouraged and might not work any more at all in the future.

But even if I put security to the minimum allowed within the browser I still could not get the applets to work within any of the browsers I tried.

I also read that new information in the Manifest Files are needed starting with Java 7. But so far I was still out of luck to even get an ejs simulation that does nothing to work, even if I tried to run a selfsigned applet with lowest security and corrected manifest file.

I have been on a holiday and will try to get on the botton of this week.

But I have to admit, that I had been running out of ideas what to try before my holiday, maybe a fresh look will help, but I also have to admit the getting applets to work in different configurations is starting to wear me out.

I thought about buying a signer certificate, to get rid of the warnings, but currently I still think selfsigned should still work and this is not the real issue (for now).

Any ideas, of where to look would be appreciated, I check the java console, I try different browsers, I try very simple ejs applets, I do have an non ejs Java 5 applet that works. I tried packing the simulation out of eclipse (file size get huge this way) but still no luck.

Any ideas are greatly appreciated, I will try them all.

Thank you so much for your reply,

Julia



Re: Re: Re: Java 7 - ejs applet does not work with it - Aug 12 2013 10:40AM
Wolfgang
74 Posts

Julia--

You are correct.  It has become much more difficult to run applets in the latest Oracle VM due to heightened security.

Signed applets delivered from a web server do work on Windows and Mac but you must purchase a digital certificate. Many of the EJS models in the ComPADRE OSP collection have been signed and can be used as applets after they have been downloaded.  (We only sign applets that have been reviewed and accepted for the Collection.)  Here a links to applet pages on OSP for you to try:

http://www.compadre.org/OSP/items/Applet.cfm?AppletID=18

http://www.compadre.org/OSP/items/Applet.cfm?AppletID=26

Be patient when accessing these applets. The download can take longer than expected when you run these applets for the first time.

Wolfgang



Re: Re: Re: Re: Java 7 - ejs applet does not work with it - Aug 12 2013 11:00AM
Julia Branke
11 Posts

Dear Wolfgang,

thank you so much for giving me an easy possibility to try certificate signed applets on the Windows 7 Java 7 machines in question, I will try these applets on those machines tomorrow and post my result.

Best wishes,

Julia



Re: Re: Re: Re: Java 7 - ejs applet does not work with it - Aug 13 2013 8:38AM
Julia Branke
11 Posts

Dear Wolfgang,

no luck, your two applets do not work on the Windows 7 Java 7 machines either, they just ask the usual questions and afterwards display a frame with white in it. And yes I waited for more than 5 minutes for any change.

Which is already more than my simulations do, they only display white.

I remembered having a problem displaying a 3D simulation that had two extra 2D windows with projection in them that did display and tried this simulation and sure enough the projection windows showed and the main simulation in the browser stayed white. Not sure, how this will help me though, since I do want to display the simulation in the browser window.

Getting rid of anything in the Java Settings that even remotely looked like security did not help. Lowest security available now is medium.

I enclose same traces with trace level 5, the only messages that show without tracelevel are the one similar to:
Missing Permissions manifest attribute for: http://www.compadre.org/OSP/document/servefile.cfm?ID=8263&DocID=888&Attachment=1
Missing Codebase manifest attribute for: http://www.compadre.org/OSP/document/servefile.cfm?ID=8263&DocID=888&Attachment=1

But I appreciate to know that there is an issue beyond the signing problem. And on my machine your applets work fine. So they mostly behave like mine do.

Best wishes,

Julia



Re: Re: Re: Re: Re: Java 7 - ejs applet does not work with it - Aug 13 2013 4:40PM
Wolfgang
74 Posts

I have retested two EJS models running as applets and they do wok on Windows 7 and 8 using Java 7 u 25 if the applet is on a server.  But as Paco points out, Oracle is making it harder and harder to run applets.

Attached File: applettest.jpg



Re: Re: Re: Re: Re: Re: Java 7 - ejs applet does not work with it - Aug 13 2013 4:53PM
Julia Branke
11 Posts

Just to clarify, the two links you gave me work for you with Java 7 Windows 7 + 8? Just to make sure before I complain that they do elsewhere to people who run our computer pool??

Thank you for trying!



Re: Re: Re: Re: Re: Re: Re: Java 7 - ejs applet does not work with it - Aug 13 2013 4:56PM
Wolfgang
74 Posts

Yes, the links I snet you work but they are slow to load.  



Re: Re: Re: Re: Re: Re: Re: Re: Java 7 - ejs applet does not work with it - Aug 13 2013 5:16PM
Julia Branke
11 Posts

Sorry, one last question, which browser did you use? Thank you!!!



Re: Re: Re: Re: Re: Re: Re: Re: Java 7 - ejs applet does not work with it - Aug 13 2013 5:44PM
Wolfgang
74 Posts

I usually use Chrome.



Re: Re: Re: Re: Re: Re: Re: Re: Java 7 - ejs applet does not work with it - Aug 13 2013 5:44PM
Wolfgang
74 Posts

I usually use Chrome.



Re: Re: Re: Re: Re: Re: Re: Re: Java 7 - ejs applet does not work with it - Aug 13 2013 5:44PM
Wolfgang
74 Posts

I usually use Chrome.



Re: Re: Re: Re: Re: Re: Re: Re: Java 7 - ejs applet does not work with it - Aug 13 2013 5:44PM
Wolfgang
74 Posts

I usually use Chrome.



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