How can I configure a Swing JFrame to close on Cmd-W?

On OS X, users expect to be able to press Cmd-W to close a window.

Can I conf开发者_StackOverflow社区igure a JFrame to do this?

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Typically, keybindings for the top-level windows are handled exclusively by the underlying OS. So on a Mac they should be already there, on a different system there is no meta key (? not sure, though, maybe has some simulation).

Anyway, you can add whatever additional keybinding you like to the JFrame's rootPane:

private void addMacCloseBinding(JFrame frame) {
    frame.getRootPane().getActionMap().put("close-window", new CloseAction(frame));
    frame.getRootPane().getInputMap(JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT)
        .put(KeyStroke.getKeyStroke("control W"), "close-window");
    frame.getRootPane().getInputMap(JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT)
        .put(KeyStroke.getKeyStroke("meta W"), "close-window");
}

public class CloseAction extends AbstractAction {

    private Window window;
    public CloseAction(Window window) {
        this.window = window;
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        if (window == null) return;
        window.dispatchEvent(new WindowEvent(
                window, WindowEvent.WINDOW_CLOSING));
    }

}

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You should be able to specify the menu shortcut like this:

menuItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_W, 
                        ActionEvent.META_MASK));