I need to fill a JPanel container with an array of smaller, square
JPanels.  They need to flow vertically down a column until they reach
the bottom of the JPanel container then start again in a new column
immediately to the right.  I'll not know how many smaller JPanels I
will use until I query a database (they are contacts goint into a
contact list grid.)

For instance, if there were 22 smaller panels:
1  6  11 16  21
2  7  12 17  22
3  8  13 18
4  9  14 19
5 10 15  20

Preferably, if the container were to be resized where the height was
less, then a row would be subtracted off and a new column created:

1  5  9    13  17  21
2  6  10  14  18  22
3  7  11  15  19
4  8  12  16  20

I'd really appreciate some advice before I reinvent the wheel.