JTable与ScrollPane行为异常

Question

I have a JPanel component with a JTable inside of it. When I run the code as it's written below, the table renders and updates correctly. As soon as I try to use the scrollPane approach, the table does not render at all. Can anyone explain to me why this is?

    private static class GameHistoryPanel extends JPanel {

        private DataModel model;
        private JTable table;
        private int currentRow;
        private int currentColumn;
        private final Dimension HISTORY_PANEL_DIMENSION = new Dimension(190,460);


        public GameHistoryPanel() {
            this.setLayout(new BorderLayout());
            this.model = new DataModel();
            this.table = new JTable(model);
            this.add(table.getTableHeader(), BorderLayout.NORTH);
            this.add(table, BorderLayout.CENTER);
//            JScrollPane scrollPane = new JScrollPane();
//            scrollPane.setViewportView(table);
//            this.add(scrollPane);
            setPreferredSize(HISTORY_PANEL_DIMENSION);
            this.currentRow = 0;
            this.currentColumn = 0;
        }

        public void increment(Board board, Move move) {
            model.setValueAt(move, currentRow, currentColumn);
            if(board.currentPlayer().getAlliance() == Alliance.WHITE) {
                currentColumn++;
            } else if (board.currentPlayer().getAlliance() == Alliance.BLACK) {
                currentRow++;
                currentColumn = 0;
            }
            validate();
            repaint();
        }
    }

Answer 1

It appears that you are using a JTable as view of a TableModel in which each cell exists in one of two states. Visible changes to a cell should result only from a change to the model, which may be examined in preparing the cell's renderer . In particular, invoking the methods validate() and repaint() should not be required. Their presence suggests that you are altering the view without the model's knowledge, which could explain the anomaly seen.

Answer 2

Try

JScrollPane scrollPane = new JScrollPane(table);
this.add(scrollPane);

Answer 3

This may be stating the obvious, but remember that you can only add a JComponent to a container once .

After

this.setLayout(new BorderLayout());
this.model = new DataModel();
this.table = new JTable(model);

either you

this.add(table, BorderLayout.CENTER);
// note that table-headers should not be added explicitly
// commented out: this.add(table.getTableHeader(), BorderLayout.NORTH);

or you

JScrollPane scrollPane = new JScrollPane(table);
this.add(scrollPane);

but trying to do both will result in problems.

I recommend using Swingx's JXTable, if at all possible. Much more flexible, and out-of-the-box column sorting and hiding/reordering.