Display jTable (char) data in jTextfield

Question

I made jFrame in netbeans with 1 jTable, 1 jTextField, and 1 Button. I put these codes inside jButtonActionPerformed.

    String kar="";
    table.setValueAt('a', 0, 0);
    table.setValueAt('b', 1, 0);
    table.setValueAt('c', 2, 0);
    table.setValueAt('d', 0, 1);
    table.setValueAt('e', 1, 1);
    table.setValueAt('f', 2, 1);

    for(int i=0;i<3;i++){
        for(int j=0;j<3;j++){
            String ar = (table.getValueAt(i, j).toString());
            kar+=ar;
        }
    }
    a.setText(kar);

So, I set the value of table as above, and I want to display it in textfield as a sentence .. So the output should be "abcdef". But I got nothing in my textfield. Can anyone help me solve this problem?

I'm pretty new at this..So I hope u guys can explain with something that's easy to understand.

Answer 1

This line:

String ar = (table.getValueAt(i, j).toString());

will throw a NullPointerException when j = 2 change the limit on j in the for loop to j<2 like this:

 for(int i=0;i<3;i++){
    for(int j=0;j<2;j++){
        String ar = (table.getValueAt(i, j).toString());
        kar+=ar;
    }
}

In the future, check the output pane to see if any Exceptions are thrown and/or run in the debugger to make sure it executes your functions all the way to the end.