arcgis flex api 访问 google 地图

package
{
import com.esri.ags.SpatialReference;
import com.esri.ags.geometry.Extent;
import com.esri.ags.geometry.MapPoint;
import com.esri.ags.layers.LOD;
import com.esri.ags.layers.TileInfo;
import com.esri.ags.layers.TiledMapServiceLayer;

import flash.net.URLRequest;

import mx.controls.Alert;

public class GoogleMapLayer extends TiledMapServiceLayer
{
public function GoogleMapLayer()
{
super();
buildTileInfo();
setLoaded(true);

}
private var _tileInfo:TileInfo=new TileInfo();
private var _baseURL:String="";

override public function get fullExtent():Extent
{
return new Extent(-9466091.13399388, 4610475.01946595, -8939371.68667449, 5183684.37031855, new SpatialReference(102113));
}
override public function get initialExtent():Extent
{
return new Extent(-9466091.13399388, 4610475.01946595, -8939371.68667449, 5183684.37031855, new SpatialReference(102113));
}

override public function get spatialReference():SpatialReference
{
return new SpatialReference(102113);
}

override public function get tileInfo():TileInfo
{
return _tileInfo;
}

override protected function getTileURL(level:Number, row:Number, col:Number):URLRequest
{

var _baseURL:String="http://khm2.google.com/kh/v=38&hl=zh-CN&x=";

var url:String=_baseURL + col.toString() + "&y=" + row.toString() + "&z=" + level.toString() + "&s=";
return new URLRequest(url);
}

private function buildTileInfo():void
{
_tileInfo.height=256;
_tileInfo.width=256;
_tileInfo.origin=new MapPoint(-20037508.342787, 20037508.342787);
_tileInfo.spatialReference=new SpatialReference(102113);
_tileInfo.lods = [

new LOD(0, 1222.99245256249, 4622324.434309),
new LOD(1, 611.49622628138, 2311162.217155),
new LOD(2, 305.748113140558, 1155581.108577),
new LOD(3, 152.874056570411, 577790.554289),
new LOD(4, 76.4370282850732, 288895.277144),
new LOD(5, 38.2185141425366, 144447.638572),
new LOD(6, 19.1092570712683, 72223.819286),
new LOD(7, 9.55462853563415, 36111.909643),
new LOD(8,1.19432856685505, 4513.988705)
];
}
}
}

<?xml version="1.0" encoding="utf-8"?>
<mx:Application
xmlns:mx="http://www.adobe.com/2006/mxml"
xmlns:esri="http://www.esri.com/2008/ags"
xmlns:google="*"
>
<mx:Text text="" width="100%"/>
<esri:Map>
<google:GoogleMapLayer id="googleMap" />
</esri:Map>
</mx:Application>