[Gvsig_english] Mac OS X: ImageIO causes crashes when loading Java applets in Firefox, Camino, Opera

[Mijail]

(Resending to the international user list, because a previous attempt  
last week failed)

We have found that installing the Java extension JAI-ImageIO, used by  
gvSIG, causes crashes when a Java applet is loaded in Firefox, Opera,  
Camino and possibly other web browsers (but NOT Safari, Webkit and  
those based on their same engine).

JAI-ImageIO is installed by gvSIG on OS X in its first run, in such a  
way that it is available for the user running gvSIG; it does not  
affect other users in the computer.

To uninstall JAI-ImageIO, one only needs to delete the file  
"jai_imageio.jar" that can be found in: user's Home directory ->  
Library -> Java -> Extensions.

The same thing can be done just by pasting this in a Terminal.app  
window:
rm ~/Library/Java/jai_imageio.jar

We have found a way to avoid installing this file, so future gvSIG  
versions won't install it and will offer to instead delete it.

To GeoTools users: there is a possibility that jai_imageio.jar is  
needed by Geotools too, so deleting the file can cause GeoTools to  
stop working. You'll have to ask them for suggestions.


For those wanting more details:
Since the advent of Safari, Apple has cared a lot more of supporting  
Java in its web browser than in the rest. In fact, current browsers  
that do not use Safari's engine (like Firefox, Camino and Opera) have  
serious trouble adequately supporting Java, since the standard ways in  
other platforms do not work in OS X.
So those browsers use the open source Java Embedding Plugin  
(javaplugin.sourceforge.net), which handles the dirty work of  
interacting with the Apple JVM.
JAI-ImageIO is not supported in OS X (in fact there is no distribution  
for OS X). For gvSIG we have managed to get the basic functionality,  
but, as seen, unexpected and difficult problems do pop up. In this  
case, the Java Embedded Plugin crashes, and with it, the browser that  
is using it.
Luckily, we have found a way to sidestep the problem: we'll use JAI- 
ImageIO not as an extension, but included in the Classpath. That's  
what we will do on future gvSIG versions.

Regards.