SOLVED! Thank you.
The only one problem is AbsoluteLayout.jar is not included within my app's JAR. The solution is (via Netbeans):
1) Create new package named org.netbeans.lib.awtextra
2) Just copy-paste AbsoluteLayout.class
in the bottom of it to that package. Look at your left side of Netbeans.
3) Build and Clean again.
4) Done, perfectly.
You can see the screenshot here:
And my conclusion is we need to add new package of AbsoluteLayout within our project if our project has used AbsluteLayout. Alhamdulillah, all praises to Allah. All done. Thank you
(really solves my problem!)