Component (JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) { JLabel label = (JLabel)super.getTableCellRendererComponent(table, value, isSelected, hasFocus, row, column); String message = warningProvider.get(); label.setIcon(message != null ? WARNING_ICON : null); label.setToolTipText(message); label.setHorizontalAlignment(CENTER); label.setVerticalAlignment(CENTER); return label; }