Problem with removing last row of JTable

问题

This is my first time asking here so forgive me if something isn't appropriate, and sorry if my English isn't very good.

Well, to make it short, currently I'm developing a Java desktop app with Swing and I have a problem using table. I have rows with each row have a button to delete the row. Everything is okay (i can delete rows with no problem) until i try to delete the last row. The last row can be deleted but apparently there is an exception, something like this:

Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: 4 >= 4
    at java.util.Vector.elementAt(Vector.java:427)
    at javax.swing.table.DefaultTableModel.setValueAt(DefaultTableModel.java:648)
    at javax.swing.JTable.setValueAt(JTable.java:2710)
    at javax.swing.JTable.editingStopped(JTable.java:4712)
    at javax.swing.AbstractCellEditor.fireEditingStopped(AbstractCellEditor.java:125)

From the stack trace, it seems that "4" is my previously deleted last row index, but i have no idea how to deal with this. I already search for solution but i still can't solve it. Note that there are still other rows when i delete the last row, and after that i can't delete the others rows. The same exception also resulted when i click the delete button.

Oh. and I use removeRow() from DefaultTableModel to delete the row. Any help will be appreciated. Thanks.

EDIT These are the code I use.

public class ViewDetail extends JInternalFrame implements ActionListener {
    ...
    String column[] = { "Aaa", "Bbb", "Delete This"};

    tableModel = new DefaultTableModel();
    Object row[][] = new Object[size][column.length];

    //fill the data from db
    int r = 0;
    for (int i = 0; i < size; i++) {
    row[r][0] = ...;
    row[r][1] = ...;
    row[r][2] = "Delete";
    r++;
    }

    tableModel.setDataVector(row, column);
    table = new JTable(tableModel);

    tableColumn = table.getColumn("Aaa");
    tableColumn.setPreferredWidth(75);
    tableColumn = table.getColumn("Bbb");
    tableColumn.setPreferredWidth(75);
    tableColumn = table.getColumn("Delete This");
    tableColumn.setPreferredWidth(75);
    tableColumn.setCellRenderer(new ButtonRenderer());
    tableColumn.setCellEditor(new ButtonEditor(new JCheckBox());
     ...
}

public class ButtonRenderer extends JButton implements TableCellRenderer {
    public ButtonRenderer() {
        setOpaque(true);
    }
    public Component getTableCellRendererComponent(JTable table, Object value,
            boolean isSelected, boolean hasFocus, int row, int column) {
        if (isSelected) {
            setForeground(table.getSelectionForeground());
            setBackground(table.getSelectionBackground());
        } else {
            setForeground(table.getForeground());
            setBackground(UIManager.getColor("Button.background"));
        }
        setText((value == null) ? "" : value.toString());
        return this;
    }
}

public class ButtonEditor extends DefaultCellEditor {
    protected JButton button;
    private String label;
    private boolean isPushed;
    private JTable table;
    public ButtonEditor(JCheckBox checkBox) {
    super(checkBox);
    button = new JButton();
    button.setOpaque(true);
    button.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            fireEditingStopped();
            }
        });
    }

    public Component getTableCellEditorComponent(JTable table, Object value,
        boolean isSelected, int row, int column) {
    if (isSelected) {
        button.setForeground(table.getSelectionForeground());
        button.setBackground(table.getSelectionBackground());
    } else {
        button.setForeground(table.getForeground());
        button.setBackground(table.getBackground());
    }
    label = (value == null) ? "" : value.toString();
    button.setText(label);
    isPushed = true;
    this.table = table;
    return button;
    }

    public Object getCellEditorValue() {
    if (isPushed) {
                  DefaultTableModel tableModel = (DefaultTableModel) table.getModel();                            
                  tableModel.removeRow(table.getSelectedRow());                
            }
            isPushed = false;
    return new String(label);
    }

    public boolean stopCellEditing() {
    isPushed = false;
    return super.stopCellEditing();
}

protected void fireEditingStopped() {
        super.fireEditingStopped();
    }
}

回答1:

Swing is trying to set the new value into the row you remove! Try moving the remove code into a Runnable and use invokeLater in the swing utility class to execute it.

回答2:

could you post the code where you init, add elements and delete in your JTable?

My first guess is that you are either doing the classical mistake "I have 4 elements in my table so to delete the last one I remove(4)" when you your table goes from 0 to 3 in indices

or you are trying to remove several object in the same loop like

  for(int i = 0; i<lenght; i++){
       if(i%2==0){//every even number
         tab.remove(i);
        }
    }

then your are modifying the size of your table, the elements are shifted but your not taking it in account when removing.

those are just guesses/pointer to what might cause the problem. please post your code if this doesn't solve it

回答3:

The Table Button Column shows how you can render a column as a button and how to add an Action that is executed when the button is clicked. The example Action just happens to show how to delete a row.

回答4:

Here you need to remove only 0 th row that should be iterated

private void refreshTable() { int rowCount= model.getRowCount(); // System.out.println(rowCount);

   for(int i=0;i<rowCount;i++ ){
        model.removeRow(0);
        //System.out.println(i);
   }

}

回答5:

you can add new vaiable and check to fireEditingStopped() :

public class ButtonEditor extends DefaultCellEditor {

//create new variable 
private boolean isDeleteRow = false;
/////////////////

protected JButton button;
private String label;
private boolean isPushed;
private JTable table;
public ButtonEditor(JCheckBox checkBox) {
super(checkBox);
button = new JButton();
button.setOpaque(true);
button.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent e) {
        fireEditingStopped();
        }
    });
}

public Component getTableCellEditorComponent(JTable table, Object value,
    boolean isSelected, int row, int column) {
if (isSelected) {
    button.setForeground(table.getSelectionForeground());
    button.setBackground(table.getSelectionBackground());
} else {
    button.setForeground(table.getForeground());
    button.setBackground(table.getBackground());
}
label = (value == null) ? "" : value.toString();
button.setText(label);
isPushed = true;
this.table = table;

// set false when click to button
isDeleteRow = false; 
/////////////////
return button;
}

public Object getCellEditorValue() {
if (isPushed) {

              // set true when isPushed button
              isDeleteRow = true;   
              /////////////////

        }
        isPushed = false;
return new String(label);
}

public boolean stopCellEditing() {
isPushed = false;
return super.stopCellEditing();
}

protected void fireEditingStopped() {
    super.fireEditingStopped();

     //check if isDeleteRow, remove row
     if(isDeleteRow)
     {
          DefaultTableModel tableModel = (DefaultTableModel) table.getModel();                            
          tableModel.removeRow(table.getSelectedRow());   
     }
     /////////////////
}
}

来源：https://stackoverflow.com/questions/4274544/problem-with-removing-last-row-of-jtable

标签

java

swing

jtable

row