how to avoid duplicating JTable columns in java?

Question

i want to add a cloumn to a jtable when a radio button is being clicked. but when i click it twice two columns are being added to the table. here's my code

 dtm = (DefaultTableModel) viewTable.getModel();
    dtm.setRowCount(0);
    TableColumnModel model=viewTable.getColumnModel();
    boolean found=false;
    for (int i = 0; i < viewTable.getColumnCount(); i++) {
        if (model.getColumn(i).getIdentifier().equals("customer Id")) {
            found=true;
            break;
        }


    if (found==false) {
       dtm.addColumn("customer Id");

    }

don't know how to fix it..

Answer 1

This code would help you. Call the below method on actionPerformed of the check box and if it is true. Validating it based on the column header.

private static void addColumn( final JTable table, final String newColumnHeader )
{
    final JTableHeader header = table.getTableHeader();
    final int columnCount = header.getColumnModel().getColumnCount();
    boolean addColumn = true;
    for( int index = 0; index < columnCount; index ++ )
    {
        final Object headerValue = header.getColumnModel().getColumn(index).getHeaderValue();
        if( newColumnHeader.equals( headerValue ) )
        {
            JOptionPane.showMessageDialog(null, "Column already exists" );
            addColumn = false;
            break;
        }
    }

    if( addColumn )
    {
        final TableColumn newCol = new TableColumn();
        newCol.setHeaderValue(newColumnHeader);
        table.getColumnModel().addColumn(newCol);
    }

}

It is good to disable the checkbox if it is already clicked ;) if you do not want a huge code.