问如何减少3个swing复选框之间的空间？

EN

JPanel formattingGroup = createGroupWithName("Formatting");
        formattingGroup.setMinimumSize(new Dimension(250, 20));
        formattingGroup.setLayout(new GridLayout(5, 0));
        add(formattingGroup);

        final JCheckBox showSurface = new JCheckBox("Show surface");
        showSurface.setSelected(true);
        formattingGroup.add(showSurface);

        final JCheckBox showTerrain = new JCheckBox("Show terrain");
        showTerrain.setSelected(true);
        formattingGroup.add(showTerrain);

        final JCheckBox showVehicleStatus = new JCheckBox("Show vehicle status");
        showVehicleStatus.setSelected(true);
        formattingGroup.add(showVehicleStatus);

        JPanel pnl = createGroupWithName("Depth Stretch");
        formattingGroup.add(pnl);
        JSlider slider = new JSlider(0, 10);
        pnl.add(slider);