Develop Reference

Working Application Stops Working With 'Main Class Not Found On'. No Changes have been made

I have an application (written about 10 years ago by someone else who is retired) that resides on a Stand-Alone Windows XP PC.
It was devleoped using NetBeans (Currently we have 6.9 installed on the PC) and controls a testbench for running component testing.
The application, initiated by a batch file on the desktop, has functioned perfectly well for Approximately 10 years.
However, 2 days ago it just stopped working with a message
'File Not Found' with the correct path and filename to a Config File that resides in a directory on the PC. This file exists.
I tried to run the application from the Dos command line (in the DIST ribution directory) using
Java -jar “AdBlue.jar”
This resulted in an error message being returned
'Exception In Thread "main" java.lang.UnsupportedClassVersionError ..... Could Not Find The Main Class"
No changes have been made to the PC.
It is the same Operating system (Windows XP - Shortly To Be Upgraded)
The java version has not been changed
The application has not been changed
The config file is still in the same directory
The permissions on the Config file have not been changed
I have checked Properties/Run and 'AdBlue.Main' is selected.
I am at a loss.
I would appreciate it if someone could point me (Someone who has not used java and Netbeans before) in the right direction. The test bench has come to a stand still and it will affect out production line shortly

We have found that teh file being searched for is corrupt.
It has been recreated and appears to have solved the problem
Thanks for all of the replies
Kind regards
Iain

java application trouble on raspbian

I'm trying to run a java application on my rapsberry but I face some problems when I run this.
The application is successfully compiling and running, but I have a warning that seems to be the reason why it doesn't work well.
My application uses Telldus devices : The TellStick duo and I should see on the screen my devices and sensors to add them (it works on my computer), but the problem is that the application seems not recognize devices, and it could be caused by this warning :
ouput in my console
I (think) have understood that it can't find the file libTelldusCore.so, in the linux-arm folder. But after some research, I don't find the linux-arm folder.
Maybe I have did something bad, maybe I have forgotten something, I'm quite beginner with raspberry's systems.
So, if someone could help me, I would be very thankful.

Have you installed telldus-core library?
If you have not, try this, might help:
apt-.get install cmake libftdi-dev libconfuse-dev
wget http://download.telldus.se/TellStick/Software/telldus-core/telldus-core-2.1.1.tar.gz
tar -zxf telldus-core-2.1.1.tar.gz
cd telldus-core-2.1.1
cmake .
make
make install
Source: https://www.raspberrypi.org/forums/viewtopic.php?f=26&t=26386

Internal error in eclipse when running java program

Eclipse froze on me earlier today, so I typed "top" into the command prompt and killed it. Now when I try to run a java application, I get this error:
eclipse\plugins\org.eclipse.jdt.debug_3.7.0.v20110509
That's all that shows up under details.
None of my previously working programs run, and I have no clue what this is. I have Eclipse 1.5.0 running 1.6 and 1.7 Java, depending on what program. Thanks for any help.

It is possible that you killed part of the process but not all of it. It is possible that a java process is running with a reference to this job. I would try restarting your computer to see if it will stop whatever process is referencing that jar.
Aside from a restart, then another option would be to use (in linux) pstree, filtered for your user to see if any other jobs are referencing that jar and/or java.
EDIT:
Another path is to look at log files. On linux they are in /var/log. Here's a link in that direction: http://docs.oracle.com/javase/7/docs/webnotes/tsg/TSG-Desktop/html/felog.html

Java is not working in my PC

I had installed Java in my PC and it was working perfectly. Suddenly something went wrong and now I m not able to open swing applications and its showing the error 'Java not found'. But I can run the Eclipse IDE which also needed Java to run. So I decide to reinstall the Java, but when I tried to uninstall the Java it shows the Error 1723 - There is a problem with this Windows Installer Package. So I have installed a new JDK in another location and set the PATH. Still I am not able to run the Swing application.
Can anybody help me on this?

How are you running your swing application?
If it's from the command line like java mySwingApp and you're getting java not found then your PATH isn't set properly. Make sure that the java/bin directory is on your PATH not just the top level directory. You can test your PATH by just typing java in a console window - it should print the java help page.
If you're not running from a terminal like above, then you may need to set a JAVA_HOME environment variable which points to your java installation folder. Here's a tutorial on setting JAVA_HOME
Setting JAVA_HOME
Hope this helps,
Will

This is close to jakob's answer, about trying to get your Java install setup correctly again, just with a little more detail.
I had a similar problem on my Windows 7 box where I was trying to uninstall Java and do a clean install of a newer version. Something got messed up and I would get the 1723 error message during the uninstall and attempted reinstall. Here's information about how I was able to fix the problem, and maybe this will help you:
Look at the log files for the uninstall/reinstall. On Windows 7 they can be found at c:\users\username\AppData\Local\Temp\
The java_install.logdidn't show any extra information, but I had several MSI##### log files that contained error messages about the failed uninstall. The message was: Error 1723.There is a problem with this Windows Installer package. A DLL required for this install to complete could not be run. Contact your support personnel or package vendor. Action UninstallJRE, entry: MSIUninstallJRE, library: C:\Program Files\Java\jre6\bin\regutils.dll
There was indeed no regutils.dll file, and not even the bindirectory was there. So I copied over a regutils.dll file from another computer, ran the uninstaller, and it worked. Then the new clean install of Java also worked.
So take a look at your logfiles and hopefully that will give you more detailed information about the 1723 error.

This usally happens when you delete Java files manually.
If you try to uninstall Java and it fails, it generates a log file.
Should be in C:\Users[Username]\AppData\Local\Temp
Almost at the end the missing file(s) can be found.
Try to copy that file(s) from a working installation to your computer.
Then you should be able to uninstall your Java and install a new version.

Android apk problem

When i create one apk from one machine and try to install into a device .it successfully get installed .But when i try to connect the same device to another machine and try to deploy same application from different machine.It doesnt allow me .I need to uninstall the application and then it works correctly .What is the issue for that .What i need to do to resolve this issue.
Thanks in advance.

Could you provide us with the output from console or the terminal prompt. There is usually an error, telling that the Application is already install, and you have to use the -r re-install option, OR that the apk has been signed with a diffrent certificate/key.
If its none of the above, please provide whatever error/output you get... If there is no more info on the output, please start the Dalvik monitor (ddms) and see what happens via the log...