title: Http get 404 Not Found for URL: null
body: <p>i have tried sample application like Tour of heroes.</p>
  
  <p>am trying to convert service cal to http get(InMemoryDbService) like below</p>
  
  <p><strong>hero.service.ts</strong></p>
  
  <pre><code>import {Injectable} from '@angular/core';
  import {HttpModule, Headers, Http} from '@angular/http';
  import 'rxjs/add/operator/toPromise';
  
  import {Hero} from './hero';
  
  @Injectable()
  export class HeroService {
  
      private heroesUrl = 'app/heroes'; 
  
      constructor(private http : Http) { }
  
      // working code
      //getHeroes(): Promise&lt;Hero[]&gt; {
      //    return Promise.resolve(HEROS);
      //}
  
      getHeroes(): Promise&lt;Hero[]&gt; {
          debugger;
          return this.http.get(this.heroesUrl).toPromise().then(responce =&gt; responce.json().data as Hero[]).catch(this.handleError);
  
      }
      private handleError(error: any): Promise&lt;any&gt; {
          console.error('An error occurred', error); // for demo purposes only
          return Promise.reject(error.message || error);
      }
  }
  </code></pre>
  
  <p><strong>in-memory-data.service.ts</strong></p>
  
  <pre><code>    import {InMemoryDbService} from 'angular-in-memory-web-api';
  
      export class InMemoryDataService implements InMemoryDbService {
      createDb() {
          let heroes = [
              { id: 1, name: 'Thulasi' },
              { id: 2, name: 'Bala' },
              { id: 3, name: 'Thulasi' },
              { id: 4, name: 'Thulasi' },
              { id: 5, name: 'Thulasi' },
              { id: 6, name: 'Thulasi' },
              { id: 7, name: 'Thulasi' },
              { id: 8, name: 'Thulasi' },
              { id: 9, name: 'Thulasi' },
              { id: 10, name: 'Thulasi' },
              { id: 11, name: 'Thulasi' }
          ];
          return heroes;
      }
  }
  </code></pre>
  
  <p>throws below errors:</p>
  
  <pre><code>hero-service.ts:25 An error occurred Response_body: Object
      headers: Header
      sok: false
      status: 404
      statusText: "Not Found"
      type: null
      url: null
      __proto__: Body
  HeroService.handleError @ hero-service.ts:25
      ZoneDelegate.invoke @ zone.js:232
      onInvoke @ core.umd.js:5975
      ZoneDelegate.invoke @ zone.js:231
      Zone.run @ zone.js:114
      (anonymous function) @ zone.js:502
      ZoneDelegate.invokeTask @ zone.js:265
      onInvokeTask @ core.umd.js:5966
      ZoneDelegate.invokeTask @ zone.js:264
      Zone.runTask @ zone.js:154
      drainMicroTaskQueue @ zone.js:401
      ZoneTask.invoke @ zone.js:339
      core.umd.js:2837 EXCEPTION: Uncaught (in promise): Response with status: 404 Not Found for URL: null
  </code></pre>