I have a problem with my table program. Could one tell me how to solve it?

Question

We have to make a program which is a little bit like excel. Now I have the problem, in that I want to make a field of 999 columns and 999 rows. I already tried to just at 999*999 JTextField controls but that obviously needs very long and I get an exception that there is no memory left. How could I make that better? Should I try to only render these text fields which are in use or is there a better method to make a table?

Here is my code:

tablePanel = new JPanel();
tablePanel.setLayout(new GridBagLayout());
tablePanel.setSize(100, 30);
tablePanel.setBorder(null);

JScrollPane tableScroll = new JScrollPane(tablePanel, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
//tableScroll.getVerticalScrollBar().setPreferredSize(new Dimension(0,0));
//tableScroll.getVerticalScrollBar().setUnitIncrement(25);
tableScroll.setBounds(0, 30, 30, this.getHeight());
table = new ArrayList<>();
for (int i = 0; i < 999; i++) {
    ArrayList<Component> column = new ArrayList<>();
    for (int j = 0; j < 999; j++) {
        JTextField field = new JTextField();
        field.setPreferredSize(new Dimension(100, 30));
        field.setBorder(null);
        field.setFocusCycleRoot(false);
        field.setFocusable(false);
        gbc.gridy = j;
        gbc.gridx = i;

        column.add(field);
        tablePanel.add(field, gbc);
    }
    table.add(column);
}

Answer 1

You can create a javax.swing.JTable like this:

JTable table = new JTable(999,999); // creates a 999*999 table
TableCellEditor tce = table.getCellEditor();
// use tce to follow user

and use tce to follow what the user is doing with what cell.

For a more in-depth tutorial about javax.swing.JTables, see How to Use Tables