import { Injectable } from "@angular/core";import { Http, Headers } from '@angular/http';import 'rxjs/add/Operator/timeout';import 'rxjs/add/operator/map';import 'rxjs/add/operator/toapplication/x-www-form-urlencoded;charset=UTF-8');        return http.post(url, params, { headers: headers }).timeout(3000).toPromise()            .then(response => {                if (success != null && success != undefined) {                    success(response);                }            })            .catch(() => {                if (error != null && error != undefined) {                    error();                }            });    }    static JsonString(json) {        let params = [];        for (let o in json) {            if (json.hasOwnProperty(o)) {                params.push(o + '=' + json[o]);            }        }        return params.join('&');    }}