java - Add an existing JPanel to an existing JFrame -

java - Add an existing JPanel to an existing JFrame -

i've got problem adding jpanel jframe, don't know why doesn't appear other layout not flowlayout; don't utilize flowlayout because swing components can't positioned.

this image of how flowlayout shows components:

and how should show:

can help me please.

you can split layout 3 jpanels, each own layout.

this jpanel can created (approximately) gridbaglayout, 2 columns , 4 rows.

this jpanel can created gridbaglayout, 4 columns , 3 rows.

this jpanel can created flowlayout or boxlayout, line axis.

you add together 3 jpanels main jpanel boxlayout, page axis.

java swing layout jframe jpanel