Hello. My professor directed me here to see if I could get some questions answered.

I need help with
Java and the program I am working on.
My program is made up of multiple classes, but some share the same panels. Is there a way I can put the panel in its own class and then call that panel to the other classes that use it?
I tried creating a class with all the variables and then making a method that returns the JPanel, however the compiler won't allow it. Are there any suggestions?
Is it possible to write to an Excel file with JDBC/OBDC? I figured out how to read from an Excel sheet, but I do not know how to make it write.
Once everything is saved to said Excel sheet, am I able to search through the values to look for a specific value? There is a section where I need to be able to search through the data and return what I'm asking for. This is one of the most crucial features to the program.
Finally, when I save the entire thing as an executable jar file, the images are not include. How do I get it to display the image?
This is the code I currently have:
but the image is not displayed when I turn it into a .jar file. It does show when I use Eclipse, however.
Thank you very much.