问res.json()不是HttpClient Angular 2中的函数

EN

return this.client.get('https://swapi.co/api/people/1/')
              .map((res:Response) => {
                 return  res.json(); // using maps to filter data returned form the http call this json dosn't work with http client
              }).map(data => {
                return data; // using maps of maps to filter data returned form the map
        }).flatMap((jedi) => this.http.get(jedi['homeworld'])
          .map(res => {
           return res.json().name; // using flat maps to combine data returned from two observables into one
          }).catch((error:any) => Observable.throw(error.json().error || 'Server error')));