JButton b1 = new JButton("Button 1");
JButton b2 = new JButton("Button 2");
JButton b3 = new JButton("Button 3");
Box mainBox = Box.createHorizontalBox();
Box leftBox = Box.createVerticalBox();
Box rightBox = Box.createVerticalBox();
leftBox.add(Box.createRigidArea(new Dimension(0,15)));
leftBox.add(b1);
leftBox.add(Box.createVerticalGlue());
leftBox.add(b2);
leftBox.add(Box.createRigidArea(new Dimension(0,15)));
rightBox.add(Box.createVerticalGlue());
rightBox.add(b3);
rightBox.add(Box.createVerticalGlue());
mainBox.add(Box.createHorizontalGlue());
mainBox.add(leftBox);
mainBox.add(Box.createRigidArea(new Dimension(10,0)));
mainBox.add(rightBox);
mainBox.add(Box.createHorizontalGlue());