.JAR woes. It just refuses to work for me :-(

Question

I spent a week building a simple java app from a C program I wrote a couple of years ago. The process has not been without tears, but I've enjoyed it. That is, up until the point of trying to make it into an 'executable' jar file. No matter what I do, it would refuse to launch and give 'can't find blah..' errors. After a couple of days of this and getting nowhere, it's starting to hack me off seriously.
To wipe out any oddness with my immature Java code, I dropped back to a 'hello world' basic program and tried again - but I still cannot get a working .jar out of it...
PLATFORM: Debian Linux
java version "1.6.0_14"
Java(TM) SE Runtime Environment (build 1.6.0_14-b08)
Java HotSpot(TM) Server VM (build 14.0-b16, mixed mode)
This is what I've done - can anyone spot the error?
Directory /develop/java/package1
contains:
HelloWorld.java
HelloWorld.java
public class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello, World!");
}This compiles to HelloWorld.class and it runs without any issue with:
java HelloWorld
from inside the /develop/java/package1
{funny enough from anywhere else in the filesystem it *wont* run - eg: java /develop/java/package1/HelloWorld - I'm not sure if that is relevant or standard Java security}
I have a manifest creation file in the parent directory (/develop/java/) that looks like this:
Main-Class: HelloWorld.classTo give it an Entry Point.
I try to create a simple executable .jar by running the command:
jar vcmf manifest HelloWorld.jar package1From the: /develop/java/ directory. This runs without error and creates HelloWorld.jar
jar vcmf manifest HelloWorld.jar package1
added manifest
adding: package1/(in = 0) (out= 0)(stored 0%)
adding: package1/HelloWorld.java(in = 124) (out= 101)(deflated 18%)
adding: package1/HelloWorld.class(in = 427) (out= 289)(deflated 32%)
Checking the /META-INF/MANIFEST.MF shows:
Manifest-Version: 1.0
Created-By: 1.6.0_14 (Sun Microsystems Inc.)
Main-Class: HelloWorld.classBut trying to execute it with: java -jar HelloWorld.jar throws:
Exception in thread "main" java.lang.NoClassDefFoundError: HelloWorld/class
Caused by: java.lang.ClassNotFoundException: HelloWorld.class
     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: HelloWorld.class. Program will exit.
I've tried altering paths, where I create the jar from etc, but it persists and after days of looking at this, I'm starting to wish I never bothered. What the hell am I missing here? It has to be staring me in the face?

Answer 1

mike120 wrote:
package1 is the directory - not a package name (that is, part of the path) - sorry for any confusion.It does not matter. The directory in the Jar, and the package name, must be identical. So do it one way or the other.
1) package1 package.
Source:
package package1;
public class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello, World!");
Jar content:
jar tvf HelloWorld.jar
0 Tue Dec 01 09:16:58 GMT 2009 META-INF/
95 Tue Dec 01 09:16:58 GMT 2009 META-INF/MANIFEST.MF
0 Tue Dec 01 08:24:14 GMT 2009 package1/
124 Tue Dec 01 08:24:12 GMT 2009 package1/HelloWorld.java
427 Tue Dec 01 08:24:14 GMT 2009 package1/HelloWorld.class
Manifest:
Main-Class: package1.HelloWorld2) No package.
Source:
public class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello, World!");
Jar content:
jar tvf HelloWorld.jar
0 Tue Dec 01 09:16:58 GMT 2009 META-INF/
95 Tue Dec 01 09:16:58 GMT 2009 META-INF/MANIFEST.MF
124 Tue Dec 01 08:24:12 GMT 2009 HelloWorld.java
427 Tue Dec 01 08:24:14 GMT 2009 HelloWorld.class
Manifest:
Main-Class: HelloWorld