Main class not found

[Mohamad Obagi]

I am trying to run a .jar file on vista but its giving me an error " Main class not found " however the program run on windows XP

[Bauke Scholtz]

That class is missing in the classpath. Check your %CLASSPATH% environment variable, check the current working path, check the -cp or -classpath parameter (which are in fact overriding the %CLASSPATH% environment variable), check the JAR´s manifest. For a more detailed answer, you need to give more detailed information.

After all I would consider this as a "Java in general (Beginner)" question.

[Lucas Franceschi]

//there's no reason to be aggresive with a fellow rancher, Bauke...

ok, i dont know if it will work, but try doing this:

look on the manifest file the exact name of your main class, and try to locate it on your current working path on XP, then try locating the same with the same jar file on vista...

be sure that your jar file is the same

check your classpath for missing files, files that is in XP's classpath but not on vista's

I dont see that as being a solution for you, so, please, i mean, please, provide us some more information, so that you can get helpful reponses, not just guesses....

[Bauke Scholtz]

Lucas Franceschi wrote: //there's no reason to be aggresive with a fellow rancher, Bauke...

I didn´t shoot him off or so? Were you referring to the last sentence? I don´t know what you think, but how the classpath works is covered by every decent Basic Java book/tutorial. So I don´t see how you see it as agressive.

[Mohamad Obagi]

this is the manifest:

 
Manifest-Version: 1.0
Ant-Version: Apache Ant 1.7.1
Created-By: 10.0-b22 (Sun Microsystems Inc.)
Main-Class: twilight.SC.Main
Class-Path: lib/appframework-1.0.3.jar lib/swing-worker-1.1.jar
X-COMMENT: Main-Class will be added automatically by build


   

part of Main class

    
  public static void main(String[] args) {
            
        try 
        {
            UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
        }
        catch(ClassNotFoundException e)
        {
            JOptionPane.showMessageDialog(new javax.swing.JFrame(),e.getMessage(),"Loading Error",JOptionPane.ERROR_MESSAGE);
        }
  

[Ernest Friedman-Hill]

The line

Class-Path: lib/appframework-1.0.3.jar lib/swing-worker-1.1.jar

means that this JAR file needs files named appframework-1.0.3.jar and swing-worker-1.1.jar in a lib/ directory sitting next to it to run. These things must be installed on the other machine where it works.

[Mohamad Obagi]

oh yes it may be the problem :S didn't notice it

thanks for the help

[Rob Spoor]

The javaw.exe executable, that will run JAR files when double-clicking, is quite bad in its error messages. Basically, everything that will go wrong is a "main class" error.

If you ever get this message, run the JAR file from the console:

java -jar jarfile.jar

This will print out the real stack trace. In your case it would probably print a ClassDefNotFoundError.