Http/observables在angular 2模块更新后现在不工作

Http调用在我重新安装/更新angular模块至最新版本之前起作用。现在，我发现所有Http调用/可观察对象现在都返回一个错误NOT FOUND（404[NOT FOUND]）。请告诉我什么需要更新，我忘了什么吗？这是我的密码：

NotificationService.ts：

import { Component, OnInit, Injectable } from '@angular/core';
import { Http, Response } from '@angular/http';
import 'rxjs/add/operator/map';

@Injectable()
export class NotificationService {

    constructor(private _http: Http){}

    GetAllNotifications(queryUrl: string){
       return this._http.get(queryUrl).map((response: Response) => response.json());
    }

}

NotificationComponent.ts：

import { Component, Input, OnInit, OnDestroy } from '@angular/core';
import { Http, Response } from '@angular/http';
import { Notification, NotificationType } from './notification.entity';
import { NotificationService } from './notification.service';
import 'rxjs/add/operator/map';

@Component({
    selector: 'e-notifications',
    templateUrl: './templates/notification.template.html'
})

export class NotificationComponent implements INotificationComponent {
    notifType = NotificationType;
    public notificationsCollection: Notification[];
    private queryUrl = "../../../data/notifications.json";
    notifSub: any;

    constructor(private _notificationService: NotificationService) { 
    }

    ngOnInit() {
       this.notifSub = this._notificationService.GetAllNotifications(this.queryUrl)
       .subscribe((response) => this.notificationsCollection = response);
    }

    ngOnDestroy() {
        this.notifSub.unsubscribe();
    }
}

开发依赖项：

 "@angular/animations": "^4.1.1",
    "@angular/cli": "^1.0.3",
    "@angular/common": "^4.1.1",
    "@angular/compiler": "^4.1.1",
    "@angular/compiler-cli": "^4.1.1",
    "@angular/core": "^4.1.1",
    "@angular/forms": "^4.1.1",
    "@angular/http": "^4.1.1",
    "@angular/material": "^2.0.0-beta.3",
    "@angular/platform-browser": "^4.1.1",
    "@angular/platform-browser-dynamic": "^4.1.1",
    "@angular/platform-server": "^4.1.1",
    "@angular/router": "^4.1.1",

---

如果未在模块中定义提供程序，请在NotificationComponent.ts中添加提供程序

还导入可观察和HTTP_提供程序

import { Component, Input, OnInit, OnDestroy } from '@angular/core';
import {Observable} from 'rxjs/Rx';
import {HTTP_PROVIDERS} from '@angular/http';
import { Notification, NotificationType } from './notification.entity';
import { NotificationService } from './notification.service';

@Component({
    selector: 'e-notifications',
    templateUrl: './templates/notification.template.html',
    providers : [HTTP_PROVIDERS, NotificationService]
})

export class NotificationComponent implements INotificationComponent {
    notifType = NotificationType;
    public notificationsCollection: Notification[];
    private queryUrl = "../../../data/notifications.json";
    notifSub: any;

    constructor(private _notificationService: NotificationService) { 
    }

    ngOnInit() {
       this.notifSub = this._notificationService.GetAllNotifications(this.queryUrl)
       .subscribe((response) => this.notificationsCollection = response);
    }

    ngOnDestroy() {
        this.notifSub.unsubscribe();
    }
}

---

为什么要发出Http请求以获取应用程序中已经存在的数据？我将从中获取的RestfulAPI尚未准备好…那么我建议使用

MockBackend

来完成此操作，如中所示。这样，您就可以将假URL移出服务，当API确实存在时，更改的内容就更少了。@jornsharpe，谢谢您的回答。。。正是我需要的。