HTTP Angular 2.O

 // Add a new comment
    addComment (body: Object): Observable<Comment[]> {
        let bodyString = JSON.stringify(body); // Stringify payload
        let headers      = new Headers({ 'Content-Type': 'application/json' }); // ... Set content type to JSON
        let options       = new RequestOptions({ headers: headers }); // Create a request option

        return this.http.post(this.commentsUrl, body, options) // ...using post request
        .map((res:Response) => res.json()) // ...and calling .json() on the response to return data
        .catch((error:any) => Observable.throw(error.json().error || 'Server error')); //...errors if any
    }