Problem resizing JPanel on window resize

[Nyet]

I am currently working on a GUI which has a JFrame which contains a JPanel which in turn contains several JPanels. I am using GridBagLayout for all of them, yet whenever I change the window's size (maximising or manually dragging) the JPanels stay the same size. I tried using fill but it only fills to the JFrame's original size, not when I resize it.
I have tried a few things, I think it might be because I have JPanels inside JPanels, however I'd would like to be sure before changing my code that much.
Thanks a lot for your help!

[PhHein]

Hi,
read this tutorial, it's helpful. Lesson: Laying Out Components Within a Container (The Java™ Tutorials > Creating a GUI With JFC/Swing)

[Nyet]

Hi, thanks I had skimmed through that but missed the weight constraint
Now I can at least stretch the JPanel to the size of the jframe when I increase the window's size, however the JPanels inside the JPanel do not change (I add weight and fill everywhere). Is it doable or do I have to add every component to the jframe manually and remove the JPanel?

[PhHein]

No you don't need to do that. Let the LayoutManagers do the work. You can use nested LayoutManagers, like Borderlayout for the content pane and GridbagLayout for panel1 and FlowLayout for panel2 etc.

[zweibieren]

Take a good look at Box and BoxLayout