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Problem running a .jar file

karl neumann
Greenhorn

Joined: Sep 03, 2012
Posts: 5
Hello java ranchers. I developed a java applet in eclipse for the first time which I plan on uploading to my website. The applet runs great within eclipse. However, when I export this project to a jar file and try to run the jar file from a command prompt I get: "no main manifest attribute, in myClass.jar" . After searching many sites for an answer I added the following line to my MANIFEST.MF file: Main-Class: org.eclipse.jdt.myClass .When I run the jar file again I get the same message as before. I am not sure if org.eclipse.jdt is correct. I got this from the .classpath file and it's a guess. When I run the jar file again I get the same message as before. Other observations: the myClass.java source file has no main() or int() method. I don't know if that's relevant or not. I am at my wits end trying to figure this out. Please help!
Darryl Burke
Bartender

Joined: May 03, 2008
Posts: 4572
    
    5

Hello karl and welcome to the Ranch! You need to go through the tutorial trail on Developing and Deploying Java Applets.

Briefly, Applets can't be run with the java -jar command. They normally run in a browser, and can be run in the applet viewer, usually from an IDE.


luck, db
There are no new questions, but there may be new answers.
karl neumann
Greenhorn

Joined: Sep 03, 2012
Posts: 5
Thanks for the advice. I have read the tutorial and I am making progress. I have rewritten much of the source code in eclipse. Once again, the applet runs in eclipse. After having exported the project to a jar file, and creating some html code, I am now running the applet from a .htm file. When running the applet I am getting an AccessControlException: access denied("java.io.FilePermission""myPic.jpg""read"). The .jpg file is included in the jar file.
What now?
Paul Clapham
Bartender

Joined: Oct 14, 2005
Posts: 18570
    
    8

I'm guessing that your applet tries to read files from the client's system. Applets aren't allowed to do that -- for security reasons -- unless they are signed.

But let me ask: is there a particular reason you are writing an applet, rather than an ordinary Java application? If you're a beginner then it would be better to write an application.
karl neumann
Greenhorn

Joined: Sep 03, 2012
Posts: 5
The applet is for my website. Thanks for the sales pitch.
Paul Clapham
Bartender

Joined: Oct 14, 2005
Posts: 18570
    
    8

Okay. Then why is your applet trying to read files from the client machine?
karl neumann
Greenhorn

Joined: Sep 03, 2012
Posts: 5
Here is my applet: besteartraining.com
spare me the advice please.
Paul Clapham
Bartender

Joined: Oct 14, 2005
Posts: 18570
    
    8

Okay. Then do you still have a question? If so, then what is it?
Paul Clapham
Bartender

Joined: Oct 14, 2005
Posts: 18570
    
    8

Also, as a moderator I'm required to give you advice about certain topics. So I would just like to remind you that this forum has a rule, and that rule is "Be Nice".
karl neumann
Greenhorn

Joined: Sep 03, 2012
Posts: 5
If your advice to beginners is to refer them to the java api, then don't bother. We can find it on own. If you are the moderator, I don't need your worthless forum. You know what you can do with yourself!
James Boswell
Bartender

Joined: Nov 09, 2011
Posts: 1025
    
    5

All the best Karl
 
I agree. Here's the link: http://aspose.com/file-tools
 
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