Problemas Implementação TableModel{HELP]

import java.util.ArrayList;

import java.util.List;

import javax.swing.table.AbstractTableModel;

public class ClienteTableModel extends AbstractTableModel

{

private final int COL_COD = 0;

private final int COL_CAT = 1;

private List CatClientes;

public ClienteTableModel()
{
    CatClientes = new ArrayList();
}

public ClienteTableModel(List lista)
{
    this();
    CatClientes.addAll(lista);
}   
        
public int getRowCount() {
    return CatClientes.size();
}

public int getColumnCount() {
    return 2;
}

@Override
public String getColumnName(int column)
{
     if (column == COL_COD) 
     { 
         return "Código";
     } 
     else if (column == COL_CAT) 
     {
        return "Cateria";
     }
    return "";

}
@Override
public Class getColumnClass (int columnIndex)
{
    if (columnIndex == COL_COD) 
    {
        return Integer.class;
    } 
    else if (columnIndex == COL_CAT) 
    {
        return String.class;
    }
    return String.class;



}

public Object getValueAt(int rowIndex, int columnIndex) 
{
   CatCliente c = CatClientes.get(rowIndex); //aqui dá o erro!!!
    
    if (columnIndex == COL_COD) 
    {
      return Integer.class;
    } 
    
    else if (columnIndex == COL_CAT) 
    {
        return String.class;
    }

return String.class;

}