java.lang.NullPointerException on DefaultTableModel getModel()

Question

I have made a JTable with DefaultTableModel, I add data inside and everything, but when I try to retrieve it I get NullPointerException here:

DefaultTableModel dm = (DefaultTableModel)finishedSaleTable.getModel();

private DefaultTableModel finishedSaleModel;
private JTable finishedSaleTable;

public SaleUI() { 
String finishedSaleColumns [] = {"#", "Customer", "Employee",  "Products", "# Products", "Discount", "Price", "Date"};
        finishedSaleModel = new DefaultTableModel(null, finishedSaleColumns);
        finishedSaleTable = new JTable(finishedSaleModel){
            public boolean isCellEditable(int rowIndex, int colIndex) {
                return false;
            }
        };
        finishedSaleTable.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
        finishedSaleTable.getColumnModel().getColumn(0).setPreferredWidth(40);
        finishedSaleTable.getColumnModel().getColumn(1).setPreferredWidth(100);
        finishedSaleTable.getColumnModel().getColumn(2).setPreferredWidth(100);
        finishedSaleTable.getColumnModel().getColumn(3).setPreferredWidth(85);
        finishedSaleTable.getColumnModel().getColumn(4).setPreferredWidth(90);
        finishedSaleTable.getColumnModel().getColumn(6).setPreferredWidth(75);
        finishedSaleTable.getColumnModel().getColumn(7).setPreferredWidth(125);
            JScrollPane finishedSaleTableScroll = new JScrollPane(finishedSaleTable);
}

private void finishedSaleClearList()
    {
        DefaultTableModel dm = (DefaultTableModel)finishedSaleTable.getModel();
        while(dm.getRowCount() > 0)
           dm.removeRow(0);
    }

Full error:

Exception in thread "main" java.lang.NullPointerException
    at ui.SalesUI.finishedSaleClearList(SalesUI.java:641) // DefaultTableModel line
    at ui.SalesUI.finishedSaleUpdateList(SalesUI.java:674) // where I call the method
    at ui.SalesUI.<init>(SalesUI.java:248)
    at ui.SalesUI.main(SalesUI.java:752)

Please post more of your code as well as the full stacktrace for your `NullPointerException`. — Asaph, Feb 05 '13 at 23:57
Sounds more like the reference to `finishedSaleTable` is `null`, but without example code, it's impossible to be sure — MadProgrammer, Feb 06 '13 at 00:01
check to see if finishedSaleTable is null. I would do it both in the finishedSaleClearList() method and in the public SaleUI() constructor after you create it — Jason, Feb 06 '13 at 00:07

score 1 · Answer 1 · answered Feb 06 '13 at 00:02

1

It can either be one of two things. Either: finishedSaleTable is null or something inside of the getModel() is. But like the other comments, there's nothing more we can tell you without the rest of the code.

answered Feb 06 '13 at 00:02

Jason

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java.lang.NullPointerException on DefaultTableModel getModel()

1 Answers1