here i have a good working example of a typescript file i created which fetches data from a json file using http.get() 
import { Injectable } from '@angular/core';
import { Http } from '@angular/http';
import 'rxjs/add/operator/map';

@Injectable()
export class QuestionsProvider {
  	data:any;
  	url:string='https://localhost/wallpaperama/quiz/post/WebuneQuiz.php?a=quizInfo&QuizId=65&noLang=0';
  	constructor(public http: Http) {
	}

	load() {
	    return new Promise(resolve => {
	      this.http.get(this.url)
	      .map(res => res.json())
	      	.subscribe(data => {
		 		this.data = data;
		 		resolve(this.data);
		   	});
	    });
	}
}