Panel in a Panel in a Panel

The three panels that hold the label/text field pairs are added to yet another panel (called dataPanel in the code) using Boxlayout with vertical alignment. The buttons are added to their own panel. Then the dataPanel and the button panel are added to the frame. The picture shows how this works.

This idea of nesting panels is a powerful one. It may look complicated and tedious, but it is much less so than laying out a design on graph paper and specifying the exact size and location of all the components. Such a design has no flexibility. What happens if you want to add or delete a component? Everything must change. With Java's layout managers everything is dynamically adjusted.