Could not find the main class, program will exit.

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05-02-2011, 09:32 AM
CourseLanguage

Could not find the main class, program will exit.

Hey when ever I try and run a .jar file it says Could not find the main class, program will exit. I was reading about the environment variables and found they thought java was in a different directory. I also tried deleting all the java registrys before reinstalling.
05-02-2011, 09:45 AM
JosAH

Quote:

Originally Posted by CourseLanguage

Hey when ever I try and run a .jar file it says Could not find the main class, program will exit. I was reading about the environment variables and found they thought java was in a different directory. I also tried deleting all the java registrys before reinstalling.

Does you .jar file have a manifest entry that tells the JVM what the 'main' class is? Environment variables have nothing to do with this.

kind regards,

Jos
05-02-2011, 09:56 AM
CourseLanguage

Im not shore but this has happened with about 25 different jar files (all i have tried) and they work on my friends computer
05-02-2011, 10:07 AM
oomrichie

open the jar file with a compression tool like winrar and see if it contains a folder "META-INF" and a file MANIFEST.MF

the file should look similar to this

Manifest-Version: 1.0
Main-Class: package.Main

if the file has a lactation to the main class try running the jar from cmd

java -jar "jarfilename.jar"
05-02-2011, 10:14 AM
JosAH

Quote:

Originally Posted by CourseLanguage

Im not shore but this has happened with about 25 different jar files (all i have tried) and they work on my friends computer

Can you show us the names of the files in the .jar file? Open it with, say, winzip and check it. Is there a manifest entry?

kind regards,

Jos
05-02-2011, 10:44 AM
CourseLanguage

Quote:

Originally Posted by oomrichie

open the jar file with a compression tool like winrar and see if it contains a folder "META-INF" and a file MANIFEST.MF

the file should look similar to this

Manifest-Version: 1.0
Main-Class: package.Main

if the file has a lactation to the main class try running the jar from cmd

java -jar "jarfilename.jar"

I extracted it and the manifest.fm said

"
Manifest-Version: 1.0
Rsrc-Class-Path: ./ substance.jar flamingo.jar trident.jar substance-f
lamingo.jar
Class-Path: .
Rsrc-Main-Class: tfcmanager.Main
Main-Class: org.eclipse.jdt.internal.jarinjarloader.JarRsrcLoa der
"

I have already tried through cmd/batch file and it has the same problem.

and josah the main jar im trying to use is TFCMM v1.5.jar and yes it has a Manifest entry
05-02-2011, 10:54 AM
JosAH

Quote:

Originally Posted by CourseLanguage

Main-Class: org.eclipse.jdt.internal.jarinjarloader.JarRsrcLoa der

I have already tried through cmd/batch file and it has the same problem.

and josah the main jar im trying to use is TFCMM v1.5.jar and yes it has a Manifest entry

Does that class mentioned in the manifest entry exist somewhere? It's an Eclipse class ...

kind regards,

Jos
05-02-2011, 11:01 AM
CourseLanguage

yes i found JarRsrcLoader.class
05-02-2011, 11:20 AM
JosAH

Quote:

Originally Posted by CourseLanguage

yes i found JarRsrcLoader.class

Where did you find it? In the .jar file you mentioned?

kind regards,

Jos
05-02-2011, 11:49 AM
CourseLanguage

Yes in the extracted files and in that extracted folder it was org/eclipse/jdt/internal/jarinjarloader/JarRsrcLoader
05-02-2011, 12:18 PM
oomrichie

If that exact jar, runs on a different pc and works as you stated previously, i cant imagine the jar is the problem. have you tried reinstalling your jre?
05-02-2011, 12:19 PM
oomrichie

sorry i see you did reinstall my bad:D
05-02-2011, 12:24 PM
JosAH

Quote:

Originally Posted by CourseLanguage

Yes in the extracted files and in that extracted folder it was org/eclipse/jdt/internal/jarinjarloader/JarRsrcLoader

(this is going to be a slow thread); and is your JVM complaining about that file? (that it can't find it).

kínd regards,

Jos
05-02-2011, 12:46 PM
CourseLanguage

It cant find main class but this isnt the jar i have tried alot of programs. Is it possible you could teamviewer me because it would make things faster and easier?
05-02-2011, 12:56 PM
CourseLanguage

Also i think it has to do something with how i use to have java 32 bit and i changed to 64bit and i read another thread and it has something to do with my environment variables
05-03-2011, 04:44 AM
CourseLanguage

I found out that my registry for java is all wrong and so is my environment varibles. So if anyone knows how to add them or revert to default please help?
05-03-2011, 06:07 PM
ra4king

Try reinstalling Java.
05-03-2011, 10:00 PM
CourseLanguage

Quote:

Originally Posted by ra4king

Try reinstalling Java.

In my post i said i tried reinstalling alot.
05-03-2011, 10:14 PM
ra4king

Ah I didn't see that. Hmmm this is weird. If it works on another computer, then the JRE is definitely the problem here.