Question

I have a JPanel where I add a JScrollPane (see class below). I added a JTextField to verify that everything works (instead of the JScrollPane) and the text field was added to the Panel. When I try to add my JScrollPane nothing (white background) is shown. How can I fix that?

protected JPanel createContentPanel() {
    JPanel panel = new JPanel();
    panel.setLayout(new BorderLayout());

    final String[] columnNames = { "Test1", "Test2", "Test3" };
    final String[][] data = {
            { "foo1", "foo2", "foo3" },
            { "bar1", "bar2", "bar3" },
            { "bar1", "bar2", "bar3" },
            { "bar1", "bar2", "bar3" },
            { "bar1", "bar2", "bar3" },
            { "bar1", "bar2", "bar3" },
            { "bar1", "bar2", "bar3" },
            { "bar1", "bar2", "bar3" }
    };

    ScrollableTable scrollableTablePane = new ScrollableTable(data, columnNames);
    panel.add(scrollableTablePane, BorderLayout.CENTER);
    return panel;
}


public class ScrollableTable extends JScrollPane {

    public ScrollableTable(String[][] aData, String[] aColumnNames) {
        super();

        TableModel model = getTableModel(aData, aColumnNames);
        JTable overviewTable = new JTable(model);
        overviewTable.setGridColor(new Color(240, 240, 240));
        TableRowSorter<TableModel> sorter = new TableRowSorter<TableModel>(model);
        overviewTable.setRowSorter(sorter);

        this.add(overviewTable);
    }

    private TableModel getTableModel(String[][] aData, String[] aColumnNames) {
        TableModel model = new DefaultTableModel(aData, aColumnNames) {
            public Class<?> getColumnClass(int column) {
                return getValueAt(0, column).getClass();
            }
        };
        return model;
    }
}

Answer 1

To set the displayed component of a JScrollPane, use JScrollPane#setViewportView(Component) rather than add(Component).

public ScrollableTable(String[][] aData, String[] aColumnNames) {
    super();

    TableModel model = getTableModel(aData, aColumnNames);
    JTable overviewTable = new JTable(model);
    overviewTable.setGridColor(new Color(240, 240, 240));
    TableRowSorter<TableModel> sorter = new TableRowSorter<TableModel>(model);
    overviewTable.setRowSorter(sorter);

    this.setViewportView(overviewTable);
}