void () { final JPanel panel = new JPanel(new GridLayoutManager(2,3, new Insets(0,0,0,0), 0, 0)); // label textfield(span 2) // textfield(span 2) final JTextField label = new JTextField(); label.setPreferredSize(new Dimension(10,30)); final JTextField field1 = new JTextField(); field1.setPreferredSize(new Dimension(100,30)); final JTextField field2 = new JTextField(); field2.setPreferredSize(new Dimension(100,30)); panel.add(label, new GridConstraints(0,0,1,1,GridConstraints.ANCHOR_CENTER,GridConstraints.FILL_BOTH, GridConstraints.SIZEPOLICY_FIXED, GridConstraints.SIZEPOLICY_FIXED, new Dimension(0,0), null, null, 0)); panel.add(field1, new GridConstraints(0,1,1,2,GridConstraints.ANCHOR_CENTER,GridConstraints.FILL_BOTH, GridConstraints.SIZEPOLICY_WANT_GROW, GridConstraints.SIZEPOLICY_FIXED, new Dimension(0,0), null, null, 0)); panel.add(field2, new GridConstraints(1,0,1,2,GridConstraints.ANCHOR_CENTER,GridConstraints.FILL_BOTH, GridConstraints.SIZEPOLICY_WANT_GROW, GridConstraints.SIZEPOLICY_FIXED, new Dimension(0,0), null, null, 0)); panel.doLayout(); final Dimension preferredSize = panel.getPreferredSize(); assertEquals(110, preferredSize.width); assertEquals(60, preferredSize.height); }