Unable to download images in a swing applet (1.3.1) behind proxy

Question

Hi
One of my client have a proxy server and firewall and when they try to access my webserver
then all the AWT applet are downloaded and rendered on client properly. However, the swing applet written
using JDK 1.3.1 is downloaded and rendered but it doesn't display anything properly as images
are not down loaded. I have used media tracker to add images to it like oMediaTracker.addImage( oImage, index );
and then oMediaTracker.waitForAll();
Java console display at client looks as follows:
Java(TM) Plug-in: Version 1.3.1
Using JRE version 1.3.1 Java HotSpot(TM) Client VM
User home directory = C:\Documents and Settings\toy
Proxy Configuration: no proxy
c: clear console window
f: finalize objects on finalization queue
g: garbage collect
h: display this help message
l: dump classloader list
m: print memory usage
q: hide console
s: dump system properties
t: dump thread list
x: clear classloader cache
0-5: set trace level to <n>
Applet Initialization start...
Applet Image Initialization start...
Trace level set to 5: basic, net, security, ext, liveconnect ... completed.
Opening      http:MyServer/24/x.gif
Connecting     http:MyServer/24/x.gif with no proxy
Connecting
http:MyServer/24/x.gif with cookie "ASPSESSIONIDGQGQQVWC=DLNBDAOABFANEPJFFIGOOIPG;
JSESSIONID=25Ais2tF1eBkevUhAa2akocfShzNdzyL7yC1I7UhJl7Z6BLZrnQK!
-1149265879"
Opening      http:MyServer/40/y.gif
Connecting      http:MyServer/40/y.gif with no proxy
Connecting      http:MyServer/40/y.gif with cookie "ASPSESSIONIDGQGQQVWC=DLNBDAOABFANEPJFFIGOOIPG;
JSESSIONID=25Ais2tF1eBkevUhAa2akocfShzNdzyL7yC1I7UhJl7Z6BLZrnQK!
-1149265879"
Opening     http://MyServer/sun/beans/infos/PanelBeanInfo.class
Connecting     http://MyServer/sun/beans/infos/PanelBeanInfo.class with no proxy
Connecting http://MyServer/sun/beans/infos/PanelBeanInfo.class with cookie "ASPSESSIONIDGQGQQVWC=DLNBDAOABFANEPJFFIGOOIPG;
JSESSIONID=25Ais2tF1eBkevUhAa2akocfShzNdzyL7yC1I7UhJl7Z6BLZrnQK!
-1149265879"
Opening http://MyServer/java/awt/ContainerBeanInfo.class
Connecting http://MyServer/java/awt/ContainerBeanInfo.class with no proxy
Connecting http://MyServer/java/awt/ContainerBeanInfo.class
Client machine tries to access these images but i never receive a call at web server end when i see
IIS log.
CLient environment:
-Windows 2000/XP/NT
-Internet explorer 6.0 SP1 or IE 5.5 SP2
with connection->LAN Setting->Use Automatic configuration script(only checked)
-Java Plugin configured like proxies->Use Browser Setting
-JDK 1.3.1 plug in at client(downloaded and Installed automatically on demand)
-Object tag used to download applet and plugin
-Firewall and proxy(i don't know about vendor)
My webserver environment
Windows 2000/iis 5.0 with anonymous authentication and
cache-control header set to no-store (so that proxy doesn't cache anything)
QUESTIONS:
~~~~~~~~~
Q.1. When i try from home network that has a proxy then everything works fine. At client site everything except
image download works fine. I mean jars are downloaded and i can see anything drawn using JAVA API.
When i try from home i see following java console trace
Java(TM) Plug-in: Version 1.3.1
Using JRE version 1.3.1 Java HotSpot(TM) Client VM
User home directory = C:\Documents and Settings\wuko
Proxy Configuration: Automatic Proxy Configuration
c: clear console window
f: finalize objects on finalization queue
g: garbage collect
h: display this help message
l: dump classloader list
m: print memory usage
q: hide console
s: dump system properties
t: dump thread list
x: clear classloader cache
0-5: set trace level to <n>
Trace level set to 5: basic, net, security, ext, liveconnect ... completed.
Applet Initialization start...
Applet Image Initialization start...
Opening http://MyServer/24/connec.gif
Connecting http://MyServer/24/connec.gif with proxy=197.168.1.100:808
Connecting http://MyServer/24/connec.gif with cookie "ASPSESSIONIDQQGQQCYU=GBJFAOABCJFPDMGFHEKLDACA; JSESSIONID=26yu5m1b4upVuXoAoDmtMbWXQmetQpyzqjFANszo9vFubujT4qGX!-1149265879"
Opening http://MyServer/24/cool.gif
Connecting http://MyServer/24/cool.gif with proxy=197.168.1.100:808
Connecting http://MyServer/24/cool.gif with cookie "ASPSESSIONIDQQGQQCYU=GBJFAOABCJFPDMGFHEKLDACA; JSESSIONID=26yu5m1b4upVuXoAoDmtMbWXQmetQpyzqjFANszo9vFubujT4qGX!-1149265879"
etc
I can't set the plugin at client to use automatic script just like IE browser uses. This option is not supported in JRE1.3.1. Looks to be supported in JRE1.4.1. My client doesn't want to set manual proxy ip and port in plugin as they don't want to reveal this info to everyone within the company for security reason.
Q.2. Why some classes like PanelBeanInfo.class, JAppletBeanInfo.class are downloaded
from my server while it doesn't exist at my webserver. Any thing stupid IE or plugin doing
at client. Any Idea?
Thanks in advance for any help.
Ratan

Answer 1

Thanks to Mike and other friends who already replied on this topic.
Here is my research analysis:
Answer to Question 1:
~~~~~~~~~~~~~~~~~~~~~
The solution is to bundle all the images with JAR. Bundle with jar whichever needs it. However, it might require duplicacy.
Image img = null;
try
img = Toolkit.getDefaultToolkit().getImage(getClass().getResource(fileName));
catch (Exception e) { }
In this case make sure that you have image at the same location where you access it. For example if you have to access an image in package class com.awt.ui.MyClass then your image should also be at location ..\com\awt\ui
Note: It will require image duplicacy in your JAR but it solves the problem. It gives the advantage of fewer download from server.
Answer to Question 2:
~~~~~~~~~~~~~~~~~~~~~
IE treats applet as an active-X and try to look for these classes in your JAR. SUN has stopped its support in JDK1.3.1 and plus. What one can do is to create dummy classes with these names and bundle it with your JAR. You have to create these dummy classes if you enable Basic authentication on your web server then browser will try to look for these classes on the server and continue to prompt you for login and password. It might bother your customer un-necessarily to enter login and password too many times prompted by plug-in (plug in).
--Ratan