NullException when I launch the midlet

Question

I can run the program in the WTK IDE using "Run" button. After that, I use "*project--->package---->create package*" to create a jar and jad file for my project. Then I goto the bin diretory and open the jad file, emulator opened it successfully and the phone window showed. Nevertheless, when I click the "launch" command to launch the app, it prompted me *"+AppName, AppName+*
*+Exception:java.lang.NullPointerException+*".
It seems the emulator didn't find the app's midp class which is the entry point and derives from Midlet. It's very strange, because when I used "jar -xf AppName.jar" to extract the jar file, the AppName.class is right there. What's wrong? Is there any limitation for the classes in the .jar file?
In addition, I didn't touch the .jad/.jar file at all, they were created by WTK.
Any comments are welcome and many thanks!

Answer 1

Do you mean I need add a package?No, I don't mean you need to add a package statement :-) but the only ways I could reproduce your problem were
-- by omitting a package statement and placing the .java file in a subfolder of src.
-- by including a package statement and placing the .java file in the src folder.
Now I add a package name test in the source filesIf by that you mean the first line of your source files ispackage test;then the files have to be in the folder src\test (*nix src/test). Did you take care of that?
and I modified the jad fileDon't modify the jad file, just Project->Package->Create Package again.
If you still have problems, post back.
db