JTable swing ID迭代器

Question

I am new on Swing Java. I have a JTable which has 3 columns (ID, state, age), I have a form with 2 JTextField and a JButton, when I click the button, a row will be added to my JTable but I want the ID to be iterated by 1, for example when I click the first time the Id is 0, when I click another time with new data entered the Id wil become 1 (0+1). There's any function to get the value of the cell in the last row in column 0? And how to initialise the Id if the JTable is empty for the first run? Here's my source code

String[] columnNames = { "ID", "state", "age" };

    int[] columnsWidth = { 188, 500, 100 };
    table = new JTable(
            new DefaultTableModel(new Object[][] {}, columnNames));
 JScrollPane scrollPane = new JScrollPane(table);
    table.setFillsViewportHeight(true);
    tableau.setLayout(new BorderLayout());
    tableau.add(scrollPane, BorderLayout.CENTER);

    logaffich.add(tableau);

Code for the button

  boutonround.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
DefaultTableModel tm = (DefaultTableModel) table.getModel();

            String numcam = age.getText();
            // Int c=0;
            String desc = display.getSelectedItem().toString();

            tm.addRow(new Object[] { new String(c), new String(desc),
                    new String(numcam) });
            table.setModel(tm);}

Answer 1

You can get an ID that is one more than the last row, and 0 if there are no rows, by just doing this:

int value = tm.getRowCount() == 0 ? 0 : 
    Integer.parseInt((String)tm.getValueAt(tm.getRowCount() - 1, 0)) + 1;

Also, there is no need to do table.setModel(tm) ; the table model automatically updates the table when changes are made.