Java JRE 1.5.0 performance problems with Squid proxy

We are also having problems with Java and Sam Learning...

If we run the test on Java Tester - Home Page going through the proxy, the java applet tries to load...but after about 10seconds gives up and a red cross is displayed.

The actual java console displays the following...

Java Plug-in 1.6.0_05
Using JRE version 1.6.0_05 Java HotSpot(TM) Client VM
User home directory = C:\Documents and Settings\test123


----------------------------------------------------
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
o: trigger logging
p: reload proxy configuration
q: hide console
r: reload policy configuration
s: dump system and deployment properties
t: dump thread list
v: dump thread stack
x: clear classloader cache
0-5: set trace level to <n>
----------------------------------------------------

load: class JavaVersionDisplayApplet.class not found.
java.lang.ClassNotFoundException: JavaVersionDisplayApplet.class
at sun.applet.AppletClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.applet.AppletClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.applet.AppletClassLoader.loadCode(Unknown Source)
at sun.applet.AppletPanel.createApplet(Unknown Source)
at sun.plugin.AppletViewer.createApplet(Unknown Source)
at sun.applet.AppletPanel.runLoader(Unknown Source)
at sun.applet.AppletPanel.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)

If we run the test on Java Tester - Home Page going out through the LEA, the java applet loads, and all is well....

Then if we change the IE proxy settings back to our proxy, everything works fine...

Log off, log back onto the machine, the problem restarts all over again...

Have looked at the settings on the proxy, there is nothing obvious on there...

Has anyone got any ideas what could be causing the problem? I'm running out of ideas...

Quote:

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Originally Posted by Snuffkins

We use a linux proxy with squid, but without the firewall and it's fine for us. I've only upgraded a couple of machines so far to test it though, but there's no problems.

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Same here. On Samlearning.com it can take 2-3 minutes for the java applet to load, if at all (at which point the students are sick of waiting and have clicked refresh a dozen times and restarted their machines, which just makes it take longer). Tried IE6, IE7, Firefox, tried to set Java to go through our ADSL line instead and tried many different versions of Java without any improvement. When we removed the linux proxy Samlearning worked almost instantly with every version of Java we tried.

We are talking about getting a hardware firewall instead anyway as our network administrator prefers them, but it is still annoying the students and staff in the meantime.

disabling requring ntlm auth for the sam learning site worked for me.

I'm not a Linux user, or any of the software you mention but we've had terrible trouble with slow Java loads (Mostly WebJetadmin). The following worked for us and may be of some use.

Right click on Java icon in taskbar,
Open Control Panel,
General Tab,
Temporary File Settings,
Remove the tick on Keep Temporary Files on My Computer.
Close and restart your browser.

Quote:

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Originally Posted by Inglebob

With regard to the Samlearning problem;

java.lang.ClassFormatError: Incompatible magic value 218774632 in class file HueFilter

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Hi All,

Apologies for resurrecting an old thread!

I was wondering if anyone found a solution to this? We have exactly the same issue here. Like most schools in Lincolnshire, we use the NetSweeper proxy - which is hosted at the LEA/NetLinc - so don't have local control other than to block/unblock websites etc. The problem occurs on all Java applets - even the test applet at java.com. If I use our old proxy (Symantec Web Security) which we still have installed but disabled, it works fine.

I've whitelisted samlearning.com/co.uk and sun.com and java.com incase Java is trying to 'phone home' - no joy. I've tried setting the proxy manually in Java Control Panel.

I know Java is working fine at a neighbouring school who also use NetSweeper.

Any ideas? Will be logging a call with Mouchel but don't hold out much hope!!

Thanks.