Question

I have used a tutorial to see how to implement JTable but I don’t know how exactly access the data of each cell to extract the data that the user put in these.

The table has 2 column and N rows

In the first column there is a String in the second there is a int

The tutorial that I have used is this

Answer 1

Every JTable has a data-model connected with it. Users may add data to this data model (e.g. by calling to the javax.swing.table.TableModel.setValueAt(Object, int, int) method) and JTable then displays them. In order to process the data from the JTable one can use the following approach:

JTable t = new JTable(/* set some table-model that will contain the data */);
...
/* get some table-model that will contain the data */
TableModel tm = t.getModel();
for (int i = 0; i < tm.getRowCount(); i++) {
  for (int j = 0; j < tm.getColumnCount(); j++) {
    Object o = tm.getValueAt(i, j);
    if (o instanceof Integer) {
      System.out.println((Integer)o);
    } else if (o instanceof String) {
      System.out.println((String)o);
    }
  }
}