Cant make an exeble jar of a package !

Question

HI,
I have made an application declaring a package 'mypack'. My directory structure is :
e:
--mypack
----msbase.jar
----mssqlserver.jar
----msutil.jar
----Main.java
----*.java
----*.class
I set my classpath as :
SET CLASSPATH=".;E:\mypack\msbase.jar;E:\mypack\mssqlserver.jar;E:\mypack\msutil.jar;E:\;"
My package name is 'mypack'. I include the line 'package mypack' on top of every source files. I compiled all the source files successfully. And also succeeded to run the application by "java mypack.Main" from anywhere( my main class is Main.java ).
But i failed to build an executable jar file for this application.
My manifest file contains :
Manifest-Version: 1.0
Main-Class: Main
Created-By: 1.2 (Sun Microsystems Inc.)
And i did from the command prompt as follows:
e:\mypack>jar cvfm App.jar mymanifest.mf *
It builds the jar file but when i click it, it says "Could not find the main class. Program will exit !"
I also tried with "Main-Class: mypack.Main" in mymanifest.mf but it also didn work.
If I dont make the package 'mypack', then i get no error. App.jar can be executed. Then whats wrong with my package ?

Answer 1

I also tried with "Main-Class: mypack.Main" in mymanifest.mf
but it also didn work.That is the way it should work; the value for Main-Class should be the fully qualified class name which includes the name of the package.
Which error message do you get in this case, "could not find the main class?" If so, the jar file probably doesn't contain the class file in the right place: jar files have an internal directory structure and a class can't be found if it's in the wrong directory. The directory structure should be the same as the package structure of the source code.
This internal directory structure is defined by the command you use to create the jar file; if the command you posted works when you don't use the "package" declaration this should work now:
e:\>jar cvfm App.jar mymanifest.mf mypack/*
You can "peek" inside a jar file and check the directory structure with any file compression program (like winzip) or by using the "t" switch with the jar tool:
e:\>jar tf App.jar