android 判断3G WIFI网络

public class ConnectionChangeReceiver extends BroadcastReceiver
{
public void onReceive( Context context, Intent intent )
{
ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService( Context.CONNECTIVITY_SERVICE );
NetworkInfo activeNetInfo = connectivityManager.getActiveNetworkInfo(); //WIFI
NetworkInfo mobNetInfo = connectivityManager.getNetworkInfo(     ConnectivityManager.TYPE_MOBILE ); //3G
if ( activeNetInfo != null )
{
Toast.makeText( context, "Active Network Type : " + activeNetInfo.getTypeName(), Toast.LENGTH_SHORT ).show();
}
if( mobNetInfo != null )
{
Toast.makeText( context, "Mobile Network Type : " + mobNetInfo.getTypeName(), Toast.LENGTH_SHORT ).show();
}
}
}