如何在Angular 4+；http拦截器

我已经实现了HttpInterceptor，用于捕获Angular 5应用程序中的请求错误。我的目标是向服务器发送另一个REST POST请求，从而保存错误日志。看起来是这样的：

@Injectable()
export class RestErrorHandler implements HttpInterceptor {

private readonly ERROR_LOGGER_PATH: string = '/logger/errorEntry';

constructor(private http: HttpClient, private restUtils: RestApiUtilsService) {}

intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
    return next.handle(req).catch((errorReponse: HttpErrorResponse) => {
        return this.handleRestError(errorReponse, req, next);
    });
}

public handleRestError(error: HttpErrorResponse, req: HttpRequest<any>, next: HttpHandler): ErrorObservable {
    let errorMessage = this.prepareErrorMessage(error);
    let entry = this.prepareEntry(errorMessage);
    this.http.post(this.restUtils.getUrl(this.ERROR_LOGGER_PATH), JSON.stringify(entry), this.restUtils.jsonResponseRequestOptions()).subscribe();
    return Observable.throw(error);
}
}

export const ErrorInterceptorProvider = {
provide: HTTP_INTERCEPTORS,
useClass: RestErrorHandler,
multi: true,
};

---

如果我创建了另一个@Injectable（）服务，通过HttpClient调用RESTAPI，并将其注入RestErrorHandler中，则不会出现错误。为什么会这样？

只需等待下一个角度释放，或应用以下所述的解决方法：

目前这是 只能通过注入喷油器并使用它来解决 HttpClient在请求时

---

以下是我的最终工作解决方案：

@Injectable()
export class RestErrorHandler implements HttpInterceptor {

private readonly ERROR_LOGGER_PATH: string = '/logger/errorEntry';

constructor(private injector: Injector, private restUtils: RestApiUtilsService) {}

intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
    return next.handle(req).catch((errorReponse: HttpErrorResponse) => {
        return this.handleRestError(errorReponse, req, next);
    });
}

public handleRestError(error: HttpErrorResponse, req: HttpRequest<any>, next: HttpHandler): ErrorObservable {
    let errorMessage = this.prepareErrorMessage(error);
    let entry = this.prepareEntry(errorMessage);
    if (!this.http) this.http = this.injector.get(HttpClient);
    this.http.post(this.restUtils.getUrl(this.ERROR_LOGGER_PATH), JSON.stringify(entry), this.restUtils.jsonResponseRequestOptions()).subscribe();
    return Observable.throw(error);
}
}

@Injectable（）
导出类RestErrorHandler实现HttpInterceptor{
私有只读错误\记录器\路径：字符串='/LOGGER/errorEntry'；
构造函数（私有注入器：注入器，私有restUtils:RestApiUtilsService）{}
截取（req:HttpRequest，next:HttpHandler）：可观察{
返回next.handle（req）.catch（（ErrorResponse:HttpErrorResponse）=>{
返回此.handleRestError（ErrorResponse，req，next）；
});
}
public handleRestError（错误：HttpErrorResponse，请求：HttpRequest，下一步：HttpHandler）：ErrorObservable{
让errorMessage=this.prepareErrorMessage（错误）；
让entry=this.prepareEntry（errorMessage）；
如果（！this.http）this.http=this.injector.get（HttpClient）；
this.http.post（this.restUtils.getUrl（this.ERROR\u LOGGER\u PATH）、JSON.stringify（entry）、this.restUtils.jsonresponseRequestStoptions（））.subscribe（）；
返回可观察抛出（错误）；
}
}

谢谢。如果有人想知道如何做的细节：看看我下面的答案。

@Injectable()
export class RestErrorHandler implements HttpInterceptor {

private readonly ERROR_LOGGER_PATH: string = '/logger/errorEntry';

constructor(private injector: Injector, private restUtils: RestApiUtilsService) {}

intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
    return next.handle(req).catch((errorReponse: HttpErrorResponse) => {
        return this.handleRestError(errorReponse, req, next);
    });
}

public handleRestError(error: HttpErrorResponse, req: HttpRequest<any>, next: HttpHandler): ErrorObservable {
    let errorMessage = this.prepareErrorMessage(error);
    let entry = this.prepareEntry(errorMessage);
    if (!this.http) this.http = this.injector.get(HttpClient);
    this.http.post(this.restUtils.getUrl(this.ERROR_LOGGER_PATH), JSON.stringify(entry), this.restUtils.jsonResponseRequestOptions()).subscribe();
    return Observable.throw(error);
}
}