In your actionPerformed method you create a new Desine object. Naturally all of its instance variables are created and initialized as per lines 7 to 35 of your posted code. In particular the JTextFields are empty. So when you access the contents of one of those JTextFields you get an empty string.
I assume you are surprised that you don't get the data from the JTextField from the original Desine object, the one which would be referred to as "this" in the actionPerformed method. You shouldn't be surprised, because you didn't ask for the data from that object.