DI与自定义HTTP和ConfigService的循环依赖关系

Question

我正在尝试实现ConfigService以检索项目中正确环境的正确配置.我目前正在遇到循环依赖

(index):28 Error: (SystemJS) Provider parse errors:
    Cannot instantiate cyclic dependency! Http: in NgModule AppModule
    Error: Provider parse errors:

在我看来,我已经探索过代码并且存在问题:

CustomHttp

constructor(backend: XHRBackend, options: RequestOptions, public spinnerService: SpinnerService, public exceptionService: ExceptionService, public configService: ConfigService) 

ExceptionService

constructor(private _notificationService: NotificationService, private _spinnerService: SpinnerService, private _configService: ConfigService, private _router: Router)

的ConfigService

constructor(private http: Http) {}

如您所见,我在此图中说明了一个循环依赖(没有任何好的约定):

我现在的问题是,如何修复它？我听说过,Injector但我不确定我是否真的可以在这种情况下使用它.

提前感谢您的回答.

Answer 1

DI无法解决循环依赖关系.解决方法是注入注入器并强制获取实例:

@Injectable()
class ConfigService {
  private http: Http;
  constructor(injector:Injector) {
    setTimeout(() => this.http = injector.get(Http);
  }
}