Try experimenting with JOptionPane-

Show an error dialog that displays the message, 'alert':
JOptionPane.showMessageDialog(null, "alert", "alert",
JOptionPane.ERROR_MESSAGE);

Show an internal information dialog with the message, 'information':
JOptionPane.showInternalMessageDialog(frame, "information",

"information", JOptionPane.INFORMATION_MESSAGE);

Show an information panel with the options yes/no and message 'choose
one':
JOptionPane.showConfirmDialog(null,
"choose one", "choose one", JOptionPane.YES_NO_OPTION);

Show an internal information dialog with the options yes/no/cancel and
message 'please choose one' and title information:
JOptionPane.showInternalConfirmDialog(frame,
"please choose one", "information",
JOptionPane.YES_NO_CANCEL_OPTION, JOptionPane.INFORMATION_MESSAGE);

Show a warning dialog with the options OK, CANCEL, title 'Warning', and
message 'Click OK to continue':
Object[] options = { "OK", "CANCEL" };
JOptionPane.showOptionDialog(null, "Click OK to continue", "Warning",
JOptionPane.DEFAULT_OPTION, JOptionPane.WARNING_MESSAGE,
null, options, options[0]);

Show a dialog asking the user to type in a String:
String inputValue = JOptionPane.showInputDialog("Please input a
value");

Show a dialog asking the user to select a String:
Object[] possibleValues = { "First", "Second", "Third" };
Object selectedValue = JOptionPane.showInputDialog(null,
"Choose one", "Input",
JOptionPane.INFORMATION_MESSAGE, null,
possibleValues, possibleValues[0]);

Hope this will help you.

Well, this is a bit tricky, because the general convention about where
to put those buttons is platform-dependent.  In particular, Windows and
the MacOS have different placements.  Fortunately, the JOptionPane
classes do this in a platform appropriate manner.

I don't know if there is some information in the LookAndFeel that allows
you to figure this out on your own.  Any help?

If you layout OK, Cancel, Apply, Help, etc. in a custom
Swing panel or dialog, there's no standard way. However,
there are good ways to do so.

I provide a free layout system that assist you in
getting good design quickly. The layout of button
bars and stacks is addressed in three levels:

1) the layout manager is technically able to layout
button bars for all platforms I'm aware of. This is
in detail more complicated than you may know. For example,
on Windows an OK command button has a minimum width
of 50 dialog units (dlu). And many layout managers
don't handle dlus.
2) the layout system comes with a ButtonBarBuilder
that assists you in building button bars that comply
with the platform's style. It uses the correct size
unit (dlu vs. pixel), the correct logical gaps,
and the default button order (OK Cancel vs. Cancel OK).
3) the layout system comes with a ButtonBarFactory
that vends prepared button bars for frequently used
bars.

See the JGoodies Forms Demo for a quick introduction:
http://www.jgoodies.com/freeware/formsdemo/index.html

Find more information about the open source JGoodies Forms:
http://www.jgoodies.com/freeware/forms/index.html

It depends. If you use the correct size, the correct gaps,
the correct margins, then it is the way for Windows apps.
On the Mac you'd layout Cancel, OK.

Hope this helps. Kind regards,
Karsten Lentzsch

Follow JOptionPane's lead.

OK on left, Cancel on right.