"Open VNC console" from Linux fails

B

bread-baker

Member
Mar 6, 2010
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We are using Proxmox Virtual Environment 1.5 , fresh install from ISO.

I have made an OpenVZ Debian-4 container. It runs great.

From Windows [ running in Virtual Box on same laptop] I can click on "Open VNC console" and that works.

From Debian Squeeze , using Firefox 3.5.6 or konqueror I get this error from a java window:
error load: "class VncViewer.class not found."

Now the problem is probably due to my Debian testing distro.
And I've been searching and installing debs etc to try to get this working..

If you have a suggestion to solve this issue please reply.
 
Probably the java VNC applet only works with Sun jvm+plugin... Try install them and make sure Sun java is the default one

Code: 
 update-alternatives --config java

[]'s
 
here is what I have, not sure but I think #4 = "Sun jvm+plugin"
There are 4 choices for the alternative java (providing /usr/bin/java).

Selection Path Priority Status
------------------------------------------------------------
0 /usr/lib/jvm/java-6-openjdk/jre/bin/java 1061 auto mode
1 /usr/bin/gij-4.3 43 manual mode
2 /usr/bin/gij-4.4 1044 manual mode
3 /usr/lib/jvm/java-6-openjdk/jre/bin/java 1061 manual mode
* 4 /usr/lib/jvm/java-6-sun/jre/bin/java 63 manual mode

Or should I install java directly from Sun/Oracle?
 
aptitude search sun-java6-plugin
i sun-java6-plugin - The Java(TM) Plug-in, Java SE 6

about:plugins shows a lot. here is part:
Java(TM) Plug-in 1.6.0_16

File name: libnpjp2.so
application/x-java-vm Java™ Plug-in Yes
application/x-java-applet Java™ Plug-in Applet Yes
application/x-java-applet;version=1.1 Java™ Plug-in Yes
application/x-java-applet;version=1.1.1 Java™ Plug-in Yes
application/x-java-applet;version=1.1.2 Java™ Plug-in Yes
application/x-java-applet;version=1.1.3 Java™ Plug-in Yes
 
I just dist a dist-upgrade on Squeeze and still have the same problem.


Jave:
Java Plug-in 1.6.0_16
Using JRE version 1.6.0_16-b01 Java HotSpot(TM) 64-Bit Server VM


Iceweasel 3.5.8


Any suggestions?
 
bread-baker said:
I just dist a dist-upgrade on Squeeze and still have the same problem.


Jave:
Java Plug-in 1.6.0_16
Using JRE version 1.6.0_16-b01 Java HotSpot(TM) 64-Bit Server VM


Iceweasel 3.5.8


Any suggestions?
Click to expand...

Is the VNC applet launched correctly?
If yes, try to enable the java console (from the java plugin control panel) and see what's going wrong.
 
when I click on "Open VNC console"

anther window opens.

the address is:
https://fbc:50026/openvz/console-direct.htm?cid=0&veid=101

which after a minute or so has a line:
'Error click for details '

after clicking:
'The application failed to run.'

click for details shows:
Java Plug-in 1.6.0_16
Using JRE version 1.6.0_16-b01 Java HotSpot(TM) 64-Bit Server VM
User home directory = /home/rob
----------------------------------------------------
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
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 VncViewer.class not found.
java.lang.ClassNotFoundException: VncViewer.class
at sun.plugin2.applet.Applet2ClassLoader.findClass(Applet2ClassLoader.java:152)
at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
at java.lang.ClassLoader.loadClass(ClassLoader.java:252)
at sun.plugin2.applet.Plugin2ClassLoader.loadCode(Plugin2ClassLoader.java:445)
at sun.plugin2.applet.Plugin2Manager.createApplet(Plugin2Manager.java:2880)
at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Plugin2Manager.java:1397)
at java.lang.Thread.run(Thread.java:619)
Caused by: java.net.ConnectException: Network is unreachable
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333)
at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:195)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:182)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
at java.net.Socket.connect(Socket.java:525)
at com.sun.net.ssl.internal.ssl.SSLSocketImpl.connect(SSLSocketImpl.java:550)
at sun.net.NetworkClient.doConnect(NetworkClient.java:161)
at sun.net.www.http.HttpClient.openServer(HttpClient.java:394)
at sun.net.www.http.HttpClient.openServer(HttpClient.java:529)
at sun.net.www.protocol.https.HttpsClient.<init>(HttpsClient.java:272)
at sun.net.www.protocol.https.HttpsClient.New(HttpsClient.java:329)
at sun.net.www.protocol.https.AbstractDelegate...t(AbstractDelegateHttpsURLConnection.java:172)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:801)
at sun.net.www.protocol.https.AbstractDelegate...t(AbstractDelegateHttpsURLConnection.java:158)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1049)
at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:373)
at sun.net.www.protocol.https.HttpsURLConnectionImpl.getResponseCode(HttpsURLConnectionImpl.java:318)
at sun.plugin2.applet.Applet2ClassLoader.getBytes(Applet2ClassLoader.java:458)
at sun.plugin2.applet.Applet2ClassLoader.access$000(Applet2ClassLoader.java:46)
at sun.plugin2.applet.Applet2ClassLoader$1.run(Applet2ClassLoader.java:126)
at java.security.AccessController.doPrivileged(Native Method)
at sun.plugin2.applet.Applet2ClassLoader.findClass(Applet2ClassLoader.java:123)
... 6 more
Exception: java.lang.ClassNotFoundException: VncViewer.class
 
bread-baker said:
when I click on "Open VNC console"

.... snip ...
load: class VncViewer.class not found.
java.lang.ClassNotFoundException: VncViewer.class
at sun.plugin2.applet.Applet2ClassLoader.findClass(Ap plet2ClassLoader.java:152)
at java.lang.ClassLoader.loadClass(ClassLoader.java:3 07)
at java.lang.ClassLoader.loadClass(ClassLoader.java:2 52)
at sun.plugin2.applet.Plugin2ClassLoader.loadCode(Plu gin2ClassLoader.java:445)
at sun.plugin2.applet.Plugin2Manager.createApplet(Plu gin2Manager.java:2880)
at sun.plugin2.applet.Plugin2Manager$AppletExecutionR unnable.run(Plugin2Manager.java:1397)
at java.lang.Thread.run(Thread.java:619)
Caused by: java.net.ConnectException: Network is unreachable

.... snip ...

Exception: java.lang.ClassNotFoundException: VncViewer.class
Click to expand...

My guess is that the Java Plugin is unable to load the VncViewer class
("load: class VncViewer.class not found" and the final " java.lang.ClassNotFoundException: VncViewer.class ")
because of some Network problem (java.net.ConnectException: Network is unreachable)

Try to raise the debug level (push 5 in the Java Plugin console) to see if you can find the cause

bye,
rob
 
Last edited:
And try also from another non-64 bit client/browser (64bit java plugin is a recent addition to Linux JRE)
 
Exception: java.lang.ClassNotFoundException: VncViewer.class
Trace level set to 5: all ... completed.
basic: Added progress listener: sun.plugin.util.GrayBoxPainter$GrayBoxProgressListener@485b78cf
network: Cache entry not found [url: https://fbc:50026/openvz/VncViewer.class, version: null]
network: Connecting https://fbc:50026/openvz/VncViewer.class with proxy=DIRECT
network: Connecting http://fbc:50026/ with proxy=DIRECT
network: Cache entry not found [url: https://fbc:50026/openvz/VncViewer/class.class, version: null]
network: Connecting https://fbc:50026/openvz/VncViewer/class.class with proxy=DIRECT
network: Connecting http://fbc:50026/ with proxy=DIRECT
basic: load: class VncViewer.class not found.
load: class VncViewer.class not found.
java.lang.ClassNotFoundException: VncViewer.class
at sun.plugin2.applet.Applet2ClassLoader.findClass(Applet2ClassLoader.java:152)
at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
at java.lang.ClassLoader.loadClass(ClassLoader.java:252)
at sun.plugin2.applet.Plugin2ClassLoader.loadCode(Plugin2ClassLoader.java:445)
at sun.plugin2.applet.Plugin2Manager.createApplet(Plugin2Manager.java:2880)
at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Plugin2Manager.java:1397)
at java.lang.Thread.run(Thread.java:619)
Caused by: java.net.ConnectException: Network is unreachable
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333)
at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:195)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:182)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
at java.net.Socket.connect(Socket.java:525)
at com.sun.net.ssl.internal.ssl.SSLSocketImpl.connect(SSLSocketImpl.java:550)
at sun.net.NetworkClient.doConnect(NetworkClient.java:161)
at sun.net.www.http.HttpClient.openServer(HttpClient.java:394)
at sun.net.www.http.HttpClient.openServer(HttpClient.java:529)
at sun.net.www.protocol.https.HttpsClient.<init>(HttpsClient.java:272)
at sun.net.www.protocol.https.HttpsClient.New(HttpsClient.java:329)
at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.getNewHttpClient(AbstractDelegateHttpsURLConnection.java:172)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:801)
at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:158)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1049)
at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:373)
at sun.net.www.protocol.https.HttpsURLConnectionImpl.getResponseCode(HttpsURLConnectionImpl.java:318)
at sun.plugin2.applet.Applet2ClassLoader.getBytes(Applet2ClassLoader.java:458)
at sun.plugin2.applet.Applet2ClassLoader.access$000(Applet2ClassLoader.java:46)
at sun.plugin2.applet.Applet2ClassLoader$1.run(Applet2ClassLoader.java:126)
at java.security.AccessController.doPrivileged(Native Method)
at sun.plugin2.applet.Applet2ClassLoader.findClass(Applet2ClassLoader.java:123)
... 6 more
Exception: java.lang.ClassNotFoundException: VncViewer.class
basic: Loading Java Applet Failed...
 
proxmox-ve computer is at work behind our pfsense firewall. I'm working from home.

so I use NAT to get at the correct system.
 
bread-baker said:
proxmox-ve computer is at work behind our pfsense firewall. I'm working from home.

so I use NAT to get at the correct system.
Click to expand...

Yes, i guessed something like that; in any case, you have to be able to download the VncViewer jar file from
https://<pvehost>:<pveport>/vncterm/VncViewer.jar

But may be the NAT is confusing the JavaPlugin classloader, even if the former succeeds ...

rob
 
Done some test with DNAT; it works, but you have to forward port 5900 as well (the applet connects to that port)
 
ok, It does work with:
Mint8 live cd .


Does not work until i figure out how to config these fresh installs: Hardy, squeeze-i386 and squeeze-amd64 .

The usual good thing about mint is that they have installed about every thing you'll need for plugins, multimedia etc.

thanks for the help!
 
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