Angular2自定义HTTP包装器请求重新发送不起作用

Question

我有一个自定义HTTP包装器，用于在Angular2中实现OAuth2，这是我的代码：

import { Injectable } from '@angular/core';
import { Http, Headers, Response, Request, BaseRequestOptions, RequestMethod } from '@angular/http';
import { Router } from '@angular/router';
import { Observable } from 'rxjs';
import { API_BASE, AUTH_TOKEN_LS_KEY, CLIENT_ID, CLIENT_PASS, LOCAL_STORAGE_USER_KEY } from 'config/constants';

@Injectable()
export class HttpService 
{
    token: any;

    constructor(private http: Http, private router: Router) {}

    get(url: string):Observable<Response> {
        return this.request(API_BASE+url, RequestMethod.Get);
    }

    post(url:string, body:any):Observable<Response> {
        return this.request(API_BASE+url, RequestMethod.Post, body);
    }

    put(url:string, body:any):Observable<Response> {
        return this.request(API_BASE+url, RequestMethod.Put, body);
    }

    patch(url:string, body:any):Observable<Response> {
        return this.request(API_BASE+url, RequestMethod.Patch, body);
    }

    delete(url: string):Observable<Response> {
        return this.request(API_BASE+url, RequestMethod.Delete);
    }

    head(url: string):Observable<Response> {
        return this.request(API_BASE+url, RequestMethod.Head);
    }

    options(url: string):Observable<Response> {
        return this.request(API_BASE+url, RequestMethod.Options);
    }

    private request(url:string, method:RequestMethod, body?:any):Observable<Response> {
        let headers = new Headers();
        this.createBearerTokenHeader(headers);
        this.createContentTypeHeader(headers);

        let options = new BaseRequestOptions();
        options.headers = headers;
        options.url = url;
        options.method = method;
        options.body = body;

        let requestOptions = {url: url, method: method, body: body};
        let request = new Request(options);
        return this.intercept(this.http.request(request), requestOptions);
    }

    private intercept(observable: Observable<Response>, requestOptions: any): Observable<Response> {
        return observable.catch((err, source) => {
            if( err.status == 401 ) {
                this.refreshToken().subscribe(result => {
                    if( result == true ) {
                        return this.request(requestOptions.url, requestOptions.method, requestOptions.body);
                    } else {
                        localStorage.removeItem(LOCAL_STORAGE_USER_KEY);
                        localStorage.removeItem(AUTH_TOKEN_LS_KEY);
                        this.router.navigate(['/']);
                    }
                });

                return Observable.empty();
            }

            return Observable.throw(err);
        });
    }

    refreshToken(): Observable<boolean> {
        this.token = JSON.parse(localStorage.getItem(AUTH_TOKEN_LS_KEY));
        let refreshToken = this.token.refresh;
        let headers = new Headers();
        this.createBearerTokenHeader(headers);
        return this.http.post(API_BASE+'/auth/default/login', {
                grant_type: "refresh_token",
                refresh_token: refreshToken,
                client_id: CLIENT_ID,
                client_secret: CLIENT_PASS
            }, 
            {headers: headers})
            .map( (response: Response) => {
                let token = response.json();
                if( token ) {
                    this.token = token.access_token;
                    localStorage.setItem(AUTH_TOKEN_LS_KEY, JSON.stringify({"access":this.token, "refresh":token.refresh_token}));
                    return true;
                }

                return false;
            });
    }

    private createBearerTokenHeader(headers) {
        this.token = JSON.parse(localStorage.getItem(AUTH_TOKEN_LS_KEY));
        if( this.token ) {
            headers.append('Authorization', 'Bearer ' + this.token.access);
        }
    }

    private createContentTypeHeader(headers) {
        headers.append('Content-Type', 'application/json; charset=utf-8');
    }
}

使用适当的标头进行请求正常。当访问令牌在服务器端过期时，刷新令牌请求完全发送并更新访问令牌并刷新本地存储上的令牌，但是我必须重新发送失败的请求，而不是再次发送没有错误只显示刷新令牌请求甚至结果条件也匹配但拦截方法中的this.request调用没有发生。我做错了什么？