How to get rid of gaps between panels when you place them on a gridlayout?

Question

I have three JPanels and I add them to a contentPane with gridlayout; the gridlayout contains 3 rows. I have annoying gaps between the panels. How can I get rid of these easily? I tried resizing my JFrame, but the spaces are still there. I also tried readjusting the gridlayout options such as HGap and Vgap, but it didn't fix the problem. I looked at some previous questions about this, but none of them solved the problem. It looks like this:

----JPanel 1 here------





----JPanel 2 here-----





----Jpanel 3 here-----

Answer 1

When set the layout manage with a GridLayout, you can specify the gaps between elements:

setLayout(new GridLayout(rows, cols, hgap, vgap));

hgap > the gap size between elements horizontally

vgap > the gap size between elements vertically

Java doc:

In addition, the horizontal and vertical gaps are set to the specified values. Horizontal gaps are placed between each of the columns. Vertical gaps are placed between each of the rows.