在Angular 2(TypeScript)下面的代码给出了3以下的错误,如何解决它们.请建议.

import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { NgModule, Component } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { HttpModule, Http } from '@angular/http';
import 'rxjs/add/operator/map';
import { Observable } from "rxjs/Observable";

@Component({
    selector: 'http-client',
    template: `
All Products
  

    

       {{product.title}}
    
  
  `})
class AppComponent {

    products: Array = [];

    theDataSource: Observable;

    constructor(private http: Http) {

        this.theDataSource = this.http.get('api/products/')
            .map(res => res.json());
    }

    ngOnInit() {
        // Get the data from the server
        this.theDataSource.subscribe(
            data => {
                if (Array.isArray(data)) {
                    this.products = data;
                } else {
                    this.products.push(data);
                }
            },
            err =>
                console.log("Can't get products. Error code: %s, URL: %s ", err.status, err.url),
            () => console.log('Product(s) are retrieved')
        );
    }
}

@NgModule({
    imports: [BrowserModule,
        HttpModule],
    declarations: [AppComponent],
    bootstrap: [AppComponent]
})
class AppModule { }

platformBrowserDynamic().bootstrapModule(AppModule);

theDataSource: Observable;

theDataSource: Observable;

import { HttpModule, Http, Response } from '@angular/http';
...
theDataSource: Observable;

theDataSource: Observable;