Is it possible to create an instance of the JDialog class that performs the calculation and get the calculation data from it into the calling class?

Question

User interface

Good afternoon! There is a main panel with combo boxes, and one of them records the mean arterial pressure. For the convenience of the user, there is a button next to the combobox, when clicked, a modal window (an instance of the JDialog class) appears, where data is inserted, which allows calculating the average based on the systolic and diastolic pressure indicators. When the JDialog instance is closed, the calculated value must be passed to the caller. Initially, I made JDialog an inner class, and there were no problems with passing. But since the calculation of the average blood pressure is also required in other places in the program, I had to make it a separate class, and I had a problem with passing the value. Maybe stupid, but I don't know how to do it. Can anyone help?