Problem implementing the abstractTableModel

Hi:

    I have constructed a JTable using the abstractTableModel but I am having problem implementing some of the mehods of the AbstractTableModel such as setValueAt and getValueAt. Also I need to create a method to insert a row.

Here is a snippet of my code:

public class DataFileTableModel extends AbstractTableModel {
 protected Vector data;
 //protected Vector columnNames ;  
 protected String datafile;
   
 private Vector tableOfVectors = new Vector();  
 private Vector columnNames;
 Vector data_vector = new Vector();

 public DataFileTableModel(String f){
   datafile = f;
   initVectors();  
   }

 public void initVectors() {
     String aLine;
     //tableOfVectors = new Vector();
     columnNames = new Vector();
   try{
       Process ls_proc = Runtime.getRuntime().exec(datafile);
       BufferedReader br = new BufferedReader(new InputStreamReader( ls_proc.getInputStream()));  
        //extract coumn names
       StringTokenizer st1 =
           new StringTokenizer(br.readLine(), "|");
          while(st1.hasMoreTokens())
              columnNames.addElement(st1.nextToken());
            //extract data
           while ((aLine = br.readLine()) != null) {  
             StringTokenizer st2 = new StringTokenizer(aLine, "|");
                while(st2.hasMoreTokens())
                {
                    tableOfVectors.add(st2.nextToken() );
                }
     }
          br.close();  
   }
   catch (Exception e) {
      e.printStackTrace();
     }
 }

 public int getRowCount() {
   return tableOfVectors.size() / getColumnCount();
 
   }

 public int getColumnCount(){
   return columnNames.size();
   }

 public String getColumnName(int columnIndex) {
   String colName = "";

   if (columnIndex <= getColumnCount())
      colName = (String)columnNames.elementAt(columnIndex);

   //return columnNames[columnIndex];
   return colName;
   }
 
 public Class getColumnClass(int columnIndex){
   return String.class;
   }
   
 public boolean isCellEditable(int rowIndex, int columnIndex) {
   return false;
   }
 
 public void insertRow(int index, Object[] element)
 {
     tableOfVectors.add(index,element);
     fireTableRowsInserted(0,0);
 }
 public void removeTask(int startRow,int endRow)
 {
      int tempRow = 0;
     int actualRows = 0;

    if (endRow < startRow)
    {
      tempRow = endRow ;
      endRow = startRow ;
      startRow = tempRow ; }

    if (startRow < 0 || endRow > getRowCount())
    return;

    actualRows = (endRow - startRow) + 1 ;

    // determine the starting point (cell) to start deleting at //
     int colCount = getColumnCount() ;  
     int cell = startRow * colCount ;

    // determine the total number of cells to delete //
    int totColCount = (getColumnCount() * actualRows) ;

    for (int d = 0; d < totColCount; d++)
    {
      tableOfVectors.remove(cell) ;
    }

    fireTableRowsDeleted(startRow,endRow) ;
   }