problem in get result than SQL to jtable

[MS_Dark]

hi all.
i have a program , now i add Operator manager to add new operator and get list of operator or delete
now Add and Delete is work fine but my ResultSet dont work and give me Null pointer Exeption

ths code in Operatormanager Class

public ArrayList<Operator> getlist() throws SQLException, ClassNotFoundException, IllegalAccessException, InstantiationException{
        
        operators = null;
        operator= null;
        
        Command_msg = "SELECT * FROM operator";
        dbmanager.getConn();
        Statement st = dbmanager.conn.createStatement();
        ResultSet res = st.executeQuery(Command_msg); 
        while(res.next()){
                operator.setName(res.getString("Name")); [COLOR=Red]// here is exeption[/COLOR]
                operator.setUsername(res.getString("Username"));
                operator.setPassword(res.getString("Password"));
                operators.add(operator);
        }
        return operators;
    }

and this code is in Display class

 OPManager.getlist();
                    int i = 0;
                    for (Core.Operator emp : operators) {
                        Table.setValueAt(emp.getName(), i, 0);
                        Table.setValueAt(emp.getUsername(), i, 1);
                        Table.setValueAt(emp.getPassword(), i, 2);
                        i++;

i waiting to your Answer.:confused: