如何使用角度2从php接收json数据？

I'm new to angular 2.I'm using http.get() for fetching a data from php file.this is my php file

<?php
header("Access-Control-Allow-Origin:*");
header('Access-Control-Allow-Headers: X-Requested-With');

include('connection.php');
$fd=new Connect();
$fd->__construct();

$data=array();

    $select=mysql_query("SELECT * FROM userData'")or mysql_error();
    $sql=mysql_num_rows($select);
    if($sql>0)
    {
        while($row=mysql_fetch_array($select))
        {

        }
    }

header('Content-Type: application/json');

    echo json_encode($data);
?>

Here I used

header("Access-Control-Allow-Origin:*");
header('Access-Control-Allow-Headers: X-Requested-With');
header('Content-Type: application/json');

to get this php file in json file still it's not working.I got whole php file in response instead of json file. this is my angular 2 component part

export class LoginComponent {
    private data;

    getData:string;

   constructor (private http:Http){}

   Getlogin(){
    //this.httpService.getUserData()

    this.http.get('dev/AngularWithPhp/login.php')
        .map(res => res.json())
        .subscribe(
                data=>this.getData = JSON.stringify(data),
                error =>alert(error),
                ()=>console.log("done"));
    }    

So what's the problem?give me suggestions...