Extending a class that uses Generics

Question

I'm trying to create a TableModel where the model deals with rows of data. Each row must be of the same "type", hence the need for generics. My RowTableModel is abstract. I'm trying to provide a concrete implentation for a model to use a List (ie. Vector or ArrayList) as the row type. But I can't figure out how to genericize the ListTableModel.
import java.util.*;
import javax.swing.table.*;
abstract class Row2TableModel<T> extends AbstractTableModel
    protected List<T> modelData;
    private List<String> columnNames;
    private Class[] columnClasses;
    private Boolean[] isColumnEditable;
    public Row2TableModel(List<String> columnNames)
        this(new ArrayList<T>(), columnNames);
    public Row2TableModel(List<T> modelData, List<String> columnNames)
        setDataAndColumnNames(modelData, columnNames);
//  Implement the TableModel interface
    public Class getColumnClass(int column)
        return Object.class;
    public int getColumnCount()
        return columnNames.size();
    public String getColumnName(int column)
        return "something";
    public int getRowCount()
        return modelData.size();
    public boolean isCellEditable(int row, int column)
        return true;
//  Example of custom methods
    public T getRow(int row)
        return modelData.get( row );
    public void insertRow(int row, T rowData)
        modelData.add(row, rowData);
        fireTableRowsInserted(row, row);
    protected void setDataAndColumnNames(List<T> modelData, List<String> columnNames)
        this.modelData = modelData;
        this.columnNames = columnNames;
        columnClasses = new Class[getColumnCount()];
        isColumnEditable = new Boolean[getColumnCount()];
        fireTableStructureChanged();
    class List2TableModel extends Row2TableModel
        public List2TableModel(List<String> columnNames)
            super(columnNames);
        public List2TableModel(List<List> modelData, List<String> columnNames)
            super(modelData, columnNames);
    //  Provide implementation of TableModel methods
        public Object getValueAt(int row, int column)
            List rowData = (List)getRow( row );
            return rowData.get( column );
        @SuppressWarnings("unchecked")
        public void setValueAt(Object value, int row, int column)
            List rowData = (List)getRow( row );
            rowData.set(column, value);
            fireTableCellUpdated(row, column);
}

Answer 1

Hi,
You mean something like that in your impementation
class List2TableModel extends Row2TableModel<List<Integer>> {
          public List2TableModel(List<String> columnNames) {
               super(columnNames);
          public List2TableModel(List<List<Integer>> modelData, List<String> columnNames) {
               super(modelData, columnNames);
          // Provide implementation of TableModel methods
          public Integer getValueAt(int row, int column) {
               List<Integer> rowData = (List<Integer>) getRow(row);
               return rowData.get(column);
          }Regards,
Alan Mehio
London,UK