Could not find the main class: projectRFID.ProjectGUI. Program will exit.

Hello,
I'm quite new in Java. I have an application with GUI. When I'm using Eclipse version 3.4.0 to run the application, all it is working perfect.
But after I generate the jar from Eclipse, using the manifest file option from there and added the ProjectGUI to it, where is the main class, and try to run from the command line I receive the next error:
root@slax:~/workspace# java -jar rfid.jar
Exception in thread "main" java.lang.NoClassDefFoundError: projectRFID/ProjectGUI
Caused by: java.lang.ClassNotFoundException: projectRFID.ProjectGUI
at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:252)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320)
Could not find the main class: projectRFID.ProjectGUI. Program will exit.
root@slax:~/workspace#
I run this application on a SLAX system with jdk6 update 7.
I tried to generate the jar file even from the command line using the manifest file option but I still receive the same error.
I hope somebody can help me!
Thank you!

cojogrizli wrote:
The structure of my project in Eclipse is src/project/files.java and in jar file is src/files.java bin/class.java Dati/ and META-INF/.That's wrong. You don't need the .java files in the jar (but you can have them, if you want, they are just not used by Java).
And each .class file must be in a directory that reflects its package. So in your example ProjectGUI.class must be in the directory projectRFID/ inside the .jar file.

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2) When posting code, code snippets, HTML/XML or input/output, please use the code tags. The code tags help retain the indentation and formatting of the sample. To use them, select the sample text and click the CODE button.
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Problem with message: Could not find the main class Program will exit

I don't get why this isn't working. Any help is appreciated.
//Code start
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Could not find the main class: hello. Program will exit.

mring001 wrote:
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cojogrizli wrote:
The structure of my project in Eclipse is src/project/files.java and in jar file is src/files.java bin/class.java Dati/ and META-INF/.That's wrong. You don't need the .java files in the jar (but you can have them, if you want, they are just not used by Java).
And each .class file must be in a directory that reflects its package. So in your example ProjectGUI.class must be in the directory projectRFID/ inside the .jar file.

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Peter__Lawrey wrote:
You have to specify the manifest with a special option (I think its was -M)
Otherwise the jar will create one (even if you provide it)No, the text file passed as a parameter will be incorporated in the manifest file generated by the JAR tool.
@OP: This will work:
JarTest.java
public class JarTest {
public static void main(String[] args) {
System.out.println("JarTest works!");
}manifest.txt
Main-Class: JarTest+(note there is an extra new line in the manifest.txt!)+
Now execute these commands:
javac JarTest.java
jar cfm MyJar.jar manifest.txt JarTest.class
java -jar MyJar.jar And on my machine, the string "JarTest works!" is displayed on the screen.
And if you look in the MANIFEST.MF file inside your jar file (you can use almost any zip-utility for this), you will see the following:
Manifest-Version: 1.0
Created-By: 1.6.0_0 (Sun Microsystems Inc.)
Main-Class: JarTestOr something similar.

Could not find the main class. Program will exit!

I have created many Executable Jar files before, and this one I did the same. When I run the jar file, (Clicking on it) I get the "Could not find the main class. Program will exit!" error message. When I run the jar file through DOS I get this Stack trace:
Exception in thread "main" java.lang.NoClassDefFoundError: javax/media/ControllerListener
at java.lang.ClassLoader.defineClass0(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:509)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:123)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:246)
at java.net.URLClassLoader.access$100(URLClassLoader.java:54)
at java.net.URLClassLoader$1.run(URLClassLoader.java:193)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:186)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:265)
at java.lang.ClassLoader.loadClass(ClassLoader.java:262)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:322)
Any Ideas? I did a search on google, and looks like others have had this problem but found no answer.
US101

There could be several reasons for getting this "Could not find main class" error message. From your stack trace it looks like the class javax/media/ControllerListener is not in your class path. Make sure your manifest file has a line like this:
Class-Path: pathToTheJarFileWithControllerListenerClass.jar otherJars.jar
This error message is also generated whenever any static initialization errors out giving the misleading error message implying that there is something wrong with the main class. Prior to starting your main class, static initialization of any static variables takes place. In my case, I was initializing a resource bundle, and forgot to include the property file in my building of the jar file. Well this failed of course and the generic error message appeared. It took many long hours to figure out it didn't have anything to do with the manifest file or the main class itself.
HTH,
John Bender

Could not find the main class ! exception.

hi,
I create one java project. for this I am using netbeans 5.
I try to run the project jar file stff.jar. When run using "java -jar stff.jar " , it throws error "could not find the main class. program will exit".
I am extracting this jar file, in manifest, main class is set.
i.e, in manifest, Main-Class: ems.emsFrame.
ems is my folder ,inside it main class kept.
here, emsFrame is my main class where " public static void main (String args[])" is located.
I am also, set the class path for that class folder(ems) and run.
The same error ("could not find the main class. program will exit") occured.
Why this error occured.
also,I am uninstall the jdk and reinstall .
whats my problem.
bye

yes sir.
In projects, inside it, in Libraries ,the SNMPInquisitor.jar is located.
inside that jar, snmp package is located.
but, when build and run, there is no problem sir.
Only when i try to run the stff.jar file (java -jar stff.jar), that time only the exception thrown.
when I double click that jar, it show, "could not find the main class. program will exit". But, I am adding the main class in manifest. when i open manifest.mf, it show, Main-Class: ems.emsFrame.
but, when i run jar thro' cmd window, it shows,
Exception in thread "main" java.lang.NoClassDefFoundError: snmp/SNMPGetException
at ems.emsFrame.<init>(emsFrame.java:1163)
at ems.emsFrame.<clinit>(emsFrame.java:1155).
i am still trying it.

Could not find the main class in Eclipse

Hey,
I've been working with Java for a few years now, but I recently set-up a new Eclipse-environment and now my Application won't run...
"Could not find the main class. Program will exit."
If I compile and run the source myself it works fine, so it must be a setting in Eclipse somewhere...
It doesn't work, even when I put the class in the default package...
It must be something very stupid, but I can't seem to find out what the problem is :(

It was only the basic Hello-World-concept;
public class Game extends JFrame {
     /** A default SerialVersionUID */
     private static final long serialVersionUID = 1L;
     public Game() {
          addKeyListener(new GameController());
          MainView view = new MainView(...);
          add(view);
      * @param args The game-options
     public static void main(String[] args) {
          Game spel = new Game();
          spel.setSize(1024, 768);
          spel.setTitle("Java Rally");
          spel.setResizable(false);
          spel.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          spel.setVisible(true);
}

Could not find the main class?

I am getting a
Could not find the main class. Program will exit!
Error with 1.3, but its because there is a jar file missing from the class path. The main class is actually there. Took me 1/2 to figure that out. This must be an error in the java command. Anyone else notice this?

Hi all
I'm stuck in the same thing as well...not only am I having problem with the JAR file I created, I'm also having problem executing other's JAR files..
For example, I created this JAR file with 'Main-Class: PrototypeTest' as it's header but when the JAR file is done and I tried to run it, it simply gives me the No Main Class Found error.
Same thing happens when I downloaded this JAR file game from Virum's website and tries to run it...no can do either...
So wondering...has anyone found the solution to this yet? I'm still looking but it is sure driving me crazy...

Could not find the main class - Problem with Webservice-Access

Hello Everybody,
I'm having serious Problems with accessing a WebService (Tomcat-Axis) per executable jar-File.
I constructed a simple GUI with 3 Textboxes 1 Button and 1 Resultbox.
I use eclipse so it was no Problem to simple generate the Backgroundclient by Processing the .wsdl-File of the WS.
Now I do this:
Head_tServiceLocator serviceLocator = new Head_tServiceLocator();
Head_t service = serviceLocator.getRPCCall();
RPCCallSoapBindingStub Head_t = (RPCCallSoapBindingStub) service;and use the Webservice like an Object.
All this works very well.
Now the Problem:
Head_t service = serviceLocator.getRPCCall();this Line has to throw a ServiceException.
If i add a try-catch Block to Process the Message JAVA tells me after i exported to JAR (with Manifest-stuff and so on) and double Click on the JAR the following :
Could not find the main Class - Program will exit.
And if i add a throws Declaration to the Methodheader it tells me:
Fatal Exception Occured - Program will exit
But if i Comment out that Line at least the GUI is being displayed (so it DOES find the main-Class). But then of course the Webservice won't be accessed.
All the JARs needed (axis.jar, commons-discovery.jar and so on) are in the same Directory as the Webservice-Client.jar
Please Help me.
Greets,
Zap

I am not done any typing mistake while creating the jar file i already followed the suggestion that you have mentioned but still the same error .
This is my MANIFEST.MF file created under META-INF folder
Manifest-Version: 1.0
Class-Path: qtjambi-4.4.3_01.jar qtjambi-win32-msvc2005-4.4.3_01.jar
Created-By: 1.5.0 (Sun Microsystems Inc.)
Main-Class: Ui_MainWindow
When i extracted the app.jar following this i got
1. META-INF folder inside that MAINFEST.MF file the contents i have already placed above
2. qtjambi-4.4.3_01.jar
3. qtjambi-win32-msvc2005-4.4.3_01.jar
4. Ui_MainWindow.class
Please tell me whats wrong in that i can also give you the app.jar file please let me know the email id ..

Could not find the main class: projectRFID.ProjectGUI. Program will exit.

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