Position 5 buttons with GridBagConstraints in Swing

[albertkao]

How to position 5 buttons with GridBagConstraints in Swing so that the first button (B1) are at the first column, the next four buttons (B2, B3, B4, B5) are grouped together with some space ( ) between the first button and next four buttons, and the fifth button (B5) is placed at the end of the row of the screen?
i.e.
B1           B2B3B4B5
The following code does not work - there is space between each button.
The posted source is a simplication of my real source code, which is more complex, so I use GridBagLayout.

JButton button = new JButton("Note");
c.fill = GridBagConstraints.LAST_LINE_START;
c.gridx = 0;
c.gridwidth = 1;
c.gridy = 5;
pane.add(button, c);

button = new JButton("Remove");
c.gridx = 5;
pane.add(button, c);

button = new JButton("Add");
c.gridx = 6;
pane.add(button, c);

button = new JButton("Add Component");
c.gridwidth = GridBagConstraints.RELATIVE;
c.gridx = 7;
pane.add(button, c);

button = new JButton("Read");
c.gridwidth = GridBagConstraints.REMAINDER;
c.gridx = 8;
pane.add(button, c);