问Ping an ip地址

EN

 String ip_address="\\10.28.81.9";
 boolean reachable=false;  
 TextView txt=(TextView) findViewById(R.id.info);
 InetAddress address;
try {
    address = InetAddress.getByName(ip_address);
    reachable =address.isReachable(3000); 
} catch (UnknownHostException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
} catch (IOException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}  
        if(reachable){
            txt.setText("Got it");
        }else{
            txt.setText("Sorry");

        }