Ajudem...Problemas no DAO

public class CadUsuarioDAO {

    
    private Database db;
    private PreparedStatement inserir;


private CadUsuarioDAO() {
    }
    
    public CadUsuarioDAO(Database db)  throws SQLException{
        this.db = db;
        

    erro de NullPointerException aqui !    inserir =  db.getCon().prepareStatement("insert into cadusuario (login, senha, nome, endereço, numero, bairro, cep, uf, fone1, fone2, fax, email, idcadusuario) values (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)");


 public int salvar(CadUsuario c){
 try{          
        
           
           inserir.setString(1, c.getNome());
           inserir.setString(2, c.getEndereço());
           inserir.setString(3, c.getBairro());
           inserir.setString(4, c.getCep());
//           inserir.setString(5, c.getCidade());
           inserir.setString(6, c.getUf());
           inserir.setString(7, c.getNumero());
           inserir.setString(8, c.getFone1());
           inserir.setString(9, c.getFone2());
           inserir.setString(10, c.getSenha());
           inserir.setString(11, c.getLogin());
           inserir.setString(12, c.getFax());
           inserir.setString(13, c.getEmail());
           inserir.setInt(14, c.getCodusuario());
     //      inserir.execute();
    return inserir.executeUpdate();
    
 }catch (Exception e){
     e.printStackTrace();
 }      
          return 0;               
       }
}