YAEJP...

Question

Yet Another Executable Jar Problem... :)
I completed the first part of the Dive Log tutorial here on Sun's website, and I decided to make an executable JAR file. I create the following manifest file and put it in the appropriate directory in the JAR:
Manifest-Version: 1.0
Created-By: Me
Main-Class: DiveLog
Note that there is a carriage return after the Main-Class statement. I run it by double-clicking and I get the usual "couldn't find main class" stuff. I open a console and run it with "java -jar divelog.jar" with the following results:
Exception in thread "main" java.lang.NoClassDefFoundError: DiveLog (wrong name:
divelog/DiveLog)
at java.lang.ClassLoader.defineClass0(Native Method)
at java.lang.ClassLoader.defineClass(Unknown Source)
at java.security.SecureClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.access$100(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClassInternal(Unknown Source)
Then I read somewhere that if your main class is part of a package, you must use its full name or whatever, so I change the Main-Class attribute to "divelog.DiveLog", as all the .java files were part of package "divelog", and run the JAR again, now getting this:
Exception in thread "main" java.lang.NoClassDefFoundError: divelog/DiveLog
Can anyone explain to me what is wrong here?

Answer 1

Update: Since the
classes were all defined as part of a package, they
were expected by the interpreter to be under a
'divelog' directory within the archive. Which is why I suggested that you run it from the command line using the command I suggested.
At first I had assumed it was a
problem with the manifest, although I did have to
change the Main-Class attribute to point to
'package.Class' instead of just 'Class'.If it doesn't run the way I suggested then it is guaranteed to have nothing to do with the manifest.