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e922. Removing a Column from a JTable Component

To remove a column to a JTable component, the component must use a table model that supports this operation. A simple implementation of such a table model is DefaultTableModel.

DefaultTableModel.removeColumn() removes the visible column, but leaves the column data in the table model. This example provides a routine that removes both the visible column and the column data.

    DefaultTableModel model = new MyDefaultTableModel();
    JTable table = new JTable(model);
    table.setModel(model);
    
    // Create 3 columns
    model.addColumn("Col1");
    model.addColumn("Col2");
    model.addColumn("Col3");
    model.addRow(new Object[]{"v1"});
    
    // Remove the first visible column without removing the underlying data
    table.removeColumn(table.getColumnModel().getColumn(0));
    
    // Disable autoCreateColumnsFromModel to prevent
    // the reappearance of columns that have been removed but
    // whose data is still in the table model
    table.setAutoCreateColumnsFromModel(false);
    
    // Remove the first visible column and its data
    removeColumnAndData(table, 0);
    
    // Remove the last visible column and its data
    removeColumnAndData(table, table.getColumnCount()-1);
    
    // Removes the specified column from the table and the associated
    // call data from the table model.
    public void removeColumnAndData(JTable table, int vColIndex) {
        MyDefaultTableModel model = (MyDefaultTableModel)table.getModel();
        TableColumn col = table.getColumnModel().getColumn(vColIndex);
        int columnModelIndex = col.getModelIndex();
        Vector data = model.getDataVector();
        Vector colIds = model.getColumnIdentifiers();
    
        // Remove the column from the table
        table.removeColumn(col);
    
        // Remove the column header from the table model
        colIds.removeElementAt(columnModelIndex);
    
        // Remove the column data
        for (int r=0; r<data.size(); r++) {
            Vector row = (Vector)data.get(r);
            row.removeElementAt(columnModelIndex);
        }
        model.setDataVector(data, colIds);
    
        // Correct the model indices in the TableColumn objects
        // by decrementing those indices that follow the deleted column
        Enumeration enum = table.getColumnModel().getColumns();
        for (; enum.hasMoreElements(); ) {
            TableColumn c = (TableColumn)enum.nextElement();
            if (c.getModelIndex() >= columnModelIndex) {
                c.setModelIndex(c.getModelIndex()-1);
            }
        }
        model.fireTableStructureChanged();
    }
    
    // This subclass adds a method to retrieve the columnIdentifiers
    // which is needed to implement the removal of
    // column data from the table model
    class MyDefaultTableModel extends DefaultTableModel {
        public Vector getColumnIdentifiers() {
            return columnIdentifiers;
        }
    }