@Injectable()
export class RestaurantesProvider {
private url: string = "http://199.169.9.9/ws/ListarEstados.ashx";
  constructor(private http: Http) {
    console.log(this.url);
  }

getRestaurantes(){
  return this.http.post(this.url, null)
  .do(this.logResponde)
  .map(this.extractData)
  .catch(this.catchError);
}

private catchError(error: Response | any){
  console.log(error);
  return Observable.throw(error.json().error || "Erro de conexção");
}

private logResponde(res: Response){
  console.log(res);
}

private extractData(res: Response){
  return res.json();
}
}

private url: string = padrao + "ListarEstados.ashx";

export class AppModule {
   private url: string = "http://199.169.0.9/ws/ListarEstados.ashx";

   getUrl(){
     return this.url;
   }
}

private url: string = AppModule.getUrl();

export class AppModule {
   private static url: string = "http://199.169.0.9/ws/ListarEstados.ashx";

   static getUrl(){
     return this.url;
   }
}

private url: string = AppModule.getUrl();

import { AppModule } from '../app/app.module';