ionic framework - android device - Observable map() not working -

at startpage.ts call metroservice's getresult function alert on chrome(i can alert sayng "s" , next well), not on android device..(only s alert..i cant' next alert) how can solve this?

startpage.ts

 export class startpage {    constructor(public navctrl: navcontroller, public navparams: navparams, public metro:metroservice) {     metro.getresults("subway");   } 

metroservice.ts

getresults(keyword:string):observable<any> {         console.log("keyword 22233: "+keyword);         alert("s");         return this.http.get('/assets/metro.json')           .map(             result =>             {               alert(result.json().data);               console.log(result.json().data.filter(item => item.station_nm.tolowercase().startswith(keyword.tolowercase()) ))               return result.json().data                 .filter(item => item.station_nm.tolowercase().startswith(keyword.tolowercase()) )             }); 

replace /assets/metro.json

assets/metro.json  

also add error handler , see if there error in http.

  return this.http.get('/assets/metro.json')       .map(         result =>{           ...         },err =>  {alert("error "+err.message);}  );