[mapserver-users] Mapplet and Browsers

[Steve Lime]

The mapplet is a totally different class of applet then the NOAA one. The NOAA applet is simply an animation control, nothing fancy (works nice though). Mapplet relies on a mechanism called "LiveConnect" that allows communication between java and the browser (via javascript). The mapplet is really stupid. It's simply reporting mouse positions to the HTML form, that's pretty much it and it's LiveConnect that allows this simplicity. Unfourtunately LiveConnect support is spotty, but should be getting better since it is part of the W3C standard for ECMAScript. In my experience:

  - MSIE 4.0+ work with a non-braindead JVM on Windows
  - Netscape 4.0 works (with the exception of 4.60) on Windows and Unix/Linux
  - Netscape 6+ does not work, which sucks since Netscape came up with the LiveConnect API
  - I've not tested Mozilla although the most recent versions of the Javascript code should support it according to the documents at the Mozilla website
  - Other browsers? Who knows...

Mac users are out of luck too, no LiveConnect support has ever existed for Mac browsers.

All of this is about par for higher end applications. Nothing like this works everywhere... *sigh*

Steve

Stephen Lime
Data & Applications Manager

Minnesota DNR
500 Lafayette Road
St. Paul, MN 55155
651-297-2937

>>> David Graham <dgraham at i3.com> 06/10/02 12:43PM >>>
Greetings Mapplet users:

I was wondering about peoples experience with use of the Mapplet with 
different browsers.

I have been developing a new site.  Currently only available on our 
internal network.  But I have found that I am having problems with 
various Browsers hanging with use of the Mapplet applet.  Now it may 
simply be issues of browser configuration/maturity but I was wondering 
what other peoples experience is.

IE 5.0.1 on Windows 2000 - Works
Mozilla 1.0 release candidate 3 on Windows 2000 - Hangs
Netscape 4.77 on Windows 2000 - Applet runs but does not load maps
Netscape 6.2 on Windows 2000 - Hangs

Mozilla 1.0 release candidate 3 on Linux - Hangs (Message is: Allocating 
more space for read msg 816 )
Netscape 4.77.1 on Linux - Works
Netscape 6.2.3 on Linux - Hangs  (Message is: Allocating more space for 
read msg 806  )
Konqueror 2.1.1 on Linux - Fails with exceptions (see below)

The reason I bring this up is if I run against another applet like the 
one at
http://www.crh.noaa.gov/radar/loop/DS.p19r0/si.kftg.shtml 
Most everything works fine

IE 5.0.1 on Windows 2000 - Works Fine
Mozilla 1.0 release candidate 3 on Windows 2000 - Works Fine
Netscape 4.77 on Windows 2000 - Works Fine
Netscape 6.2 on Windows 2000 - Works Fine

Mozilla 1.0 release candidate 3 on Linux - Works Fine
Netscape 4.77.1 on Linux - Works Fine
Netscape 6.2.3 on Linux - Works Fine
Konqueror 2.1.1 on Linux - Runs applet does not display images

Now I tried hitting the Landview site also, and it has similar 
problems.  This is not surprising since I was using there compilation of 
the mapplet. 

I went to the MapServer web site and downloaded the mapplet.zip file 
from the Utilities section and installed class files in the web server 
but did not get any better results.  I am currently unable to compile 
them since I do not have the javascript package.  But I wonder if that 
is not where the problem is.  Below is the Java Console Output form the 
Konqueror web browser.  The ClassFormatErrors occur right before it 
hangs up.  That has to do with the Javascript Object libraries.

Has anyone else been having or working on these problems?  Any input 
would be appreciated.

Dave Graham

Konqueror Java Console Output
---------------------------------
Java VM version: 1.3.0
Java VM vendor:  IBM Corporation
Unable to load JSSE SSL stream handler, https support not available
java.lang.ClassFormatError: netscape/javascript/JSObject (Bad magic number)
    at java.lang.ClassLoader.defineClass0(Native Method)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:496)
    at 
java.security.SecureClassLoader.defineClass(SecureClassLoader.java:117)
    at 
org.kde.kjas.server.KJASAppletClassLoader.findClass(KJASAppletClassLoader.java:314)
    at 
org.kde.kjas.server.KJASAppletClassLoader.loadClass(KJASAppletClassLoader.java:335)
    at mapplet.init(mapplet.java:74)
    at 
org.kde.kjas.server.KJASAppletStub.initApplet(KJASAppletStub.java:145)
    at org.kde.kjas.server.KJASAppletStub$1.run(KJASAppletStub.java:98)
    at java.lang.Thread.run(Thread.java:498)
java.lang.ClassFormatError: netscape/javascript/JSObject (Bad magic number)
    at java.lang.ClassLoader.defineClass0(Native Method)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:496)
    at 
java.security.SecureClassLoader.defineClass(SecureClassLoader.java:117)
    at 
org.kde.kjas.server.KJASAppletClassLoader.findClass(KJASAppletClassLoader.java:289)
    at 
org.kde.kjas.server.KJASAppletClassLoader.loadClass(KJASAppletClassLoader.java:335)
    at mapplet.init(mapplet.java:74)
    at 
org.kde.kjas.server.KJASAppletStub.initApplet(KJASAppletStub.java:145)
    at org.kde.kjas.server.KJASAppletStub$1.run(KJASAppletStub.java:98)
    at java.lang.Thread.run(Thread.java:498)
------------------------------------

-- 
David W. Graham
Director of Geospatial Applications Development
information integration and imaging, LLC
201 Linden St, Third Floor
Fort Collins, CO 80524
(970) 482-4400
dgraham at i3.com 
http://www.i3.com