Question

I have created a table and some buttons to remove/add rows.
Problem is, when I add a new row, I must insert a value in the field name which isn’t already on that table. Let me explain.

Here is the default table:

Now imagine i remove Station 3:

If i add a new Station, I would want to add a new Station name Station 3 (which is missing on the list) but I am adding a new Station 5 (obviously as my code is not correct).

My code for the Add Button action event is as such:

private void jButton10ActionPerformed(java.awt.event.ActionEvent evt) {                                          
    DefaultTableModel model = (DefaultTableModel)jTable1.getModel();
    String s2 = "";
    String s1 = "Station 1 Station 2 Station 3 Station 4 Station 5";
    int tb1rows = jTable1.getRowCount();
    if (tb1rows == 5) {
        // ERROR - MAXIMUM STATION NUMBER
    }
    else {
        for (int i=0; i<tb1rows;i++) {
            s2.concat(jTable1.getValueAt(i,1).toString());
            s2.concat(" ");
         }
        String[] s3=s2.split(" ");
        for (int i=0;i<s3.length;i++) {
            if (s1.contains(s3[i])) {
                System.err.println("contains");
                System.out.println(s3[i]);
            }
        }
        model.insertRow(jTable1.getRowCount(),new Object[] {jTable1.getRowCount() + 1,"Station " + (jTable1.getRowCount()+1),10,false,0,Color.BLACK});
    }
}

What’s wrong with my logic? Is there a better way to handle the problem so that I can get the “Station x” that is missing in that column so that I can re-add it?

Thanks in advance for your answers.

Answer 1

instead of all that string manipulation, you could use set mainpulations:

HashSet<String> all = new HashSet<String>();
// then populate all with your 5 station strings (loop)
HashSet<String> have = new HashSet<String>();
// then populate all with the contents of your table (loop)
all.removeAll(have);
// all now contains the ones that weren't in the table.