injector.get给undefined

Question

我正在使用Angh4，使用authservice和http服务。

当我尝试刷新jwt令牌时，通过在每次请求服务器之前检查令牌到期。为了避免循环依赖，我在auth.service.ts中使用注入器：

constructor(// private http: HttpClient,
inj: Injector) {
setTimeout(() => { this.http = inj.get(HttpClient) })
}

但是在调用http.somefunction（）时会出现错误 错误TypeError：无法读取未定义

的属性'somefunction'

我的http.service.ts如下

import { Injectable } from '@angular/core';
import { Http, Headers } from '@angular/http';
import { tokenNotExpired, JwtHelper } from 'angular2-jwt';
import { JwtAuthService } from './auth.service'
@Injectable()
export class HttpClient {
jwtHelper: JwtHelper = new JwtHelper();
constructor(private http: Http, private _jwtAuthService: JwtAuthService) { }

createAuthorizationHeader(headers: Headers) {
    let token = '';
    if (sessionStorage.getItem('token')) {
        token = sessionStorage.getItem('token')
    }

    if (token && typeof token === 'string') {
        if (this.jwtHelper.isTokenExpired(token)) {
            // get aws token using refresh_token and get jwt token
            this._jwtAuthService.refreshToken().then(refreshedtoken => {
                headers.append('Authorization', 'Bearer ' + refreshedtoken);
            });
        }
        else {
            headers.append('Authorization', 'Bearer ' + token);
        }


    }

}
getwithheader(url, header) {
    const headers = new Headers();
    headers.append('Authorization', 'Bearer ' + header);
    this.createAuthorizationHeader(headers);
    return this.http.get(url, {
        headers: headers
    });
}
get(url) {
    const headers = new Headers();
    this.createAuthorizationHeader(headers);
    return this.http.get(url, {
        headers: headers
    });
}
awspost(url, data) {
    const headers = new Headers();
    headers.append('Content-Type', 'application/x-www-form-urlencoded');
    return this.http.post(url, data, {
        headers: headers
    });
}
post(url, data) {
    const headers = new Headers();
    this.createAuthorizationHeader(headers);
    return this.http.post(url, data, {
        headers: headers
    });
}
}

和auth servce如下

import { Injectable, Injector } from '@angular/core';
import { SharedService } from './shared.service';
import { ErrorHandlerService } from './error-handler.service';
import { HttpClient } from './http.service';
import { Observable } from 'rxjs/rx';
import { Http, Response } from '@angular/http';
import * as AWS from 'aws-sdk/global';
import 'rxjs/add/operator/toPromise';
import { environment } from '../../environments/environment';
import { tokenNotExpired, JwtHelper } from 'angular2-jwt';
@Injectable()
export class JwtAuthService {
BASE_URL = this._sharedService.BASE_URL;
AWS_ACCESS_KEY = 'test';
http: HttpClient;
  jwtHelper: JwtHelper = new JwtHelper();
constructor(// private http: HttpClient,
    private _sharedService: SharedService,
    private _errorHandler: ErrorHandlerService,
    inj: Injector) {
    setTimeout(() => { this.http = inj.get(HttpClient) })
}

getAwsToken(code): any {
    const body = 'grant_type=' + environment.AWS_GRANT_TYPE + '&client_id=' + environment.AWS_CLIENT_ID + '&redirect_uri=' + environment.AWS_REDIRECT_URI + '&code_verifier=' + code;
    return this.http.awspost(environment.AWS_BASE_URL + environment.AWS_TOKEN_END_POINT + '?code=' + code, body).toPromise()
        .then((resp: Response) => resp.text())
        .catch(err => this._errorHandler.handleError(err));
}
getToken(token): any {
    return this.http.getwithheader(this.BASE_URL + '/token', token).toPromise()
        .then((resp: Response) => resp.text())
        .catch(err => this._errorHandler.handleError(err));
}
getRefreshAWSToken(refreshToken): any {
    const body = 'grant_type=refresh_token' + '&client_id=' + environment.AWS_CLIENT_ID + '&redirect_uri=' + environment.AWS_REDIRECT_URI + '&code_verifier=' + refreshToken;
    return this.http.awspost(environment.AWS_BASE_URL + environment.AWS_TOKEN_END_POINT, body).toPromise()
        .then((resp: Response) => resp.text())
        .catch(err => this._errorHandler.handleError(err));
}
refreshToken(): any {
    this.getRefreshAWSToken(sessionStorage.getItem('refreshToken'))
        .then(resp => {
            this.getToken(JSON.parse(resp).id_token)
                .then(jwtresp => {
                    sessionStorage.setItem('user', JSON.stringify(this.jwtHelper.decodeToken(jwtresp)));
                    sessionStorage.setItem('token', JSON.parse(jwtresp).token);
                    return JSON.parse(jwtresp).token
                });
        });
}
}

这里缺少什么？