public void checkIP(List<String> ip){
		System.out.println("reachable ip:----------------->");
		Socket socket = null;
        for (String url : ip) {
            boolean reachable = false;
            try {
                socket = new Socket();
                // set timeout to 3 seconds
                socket.connect(new InetSocketAddress(url, 80), 3000);
                reachable = true;
            } catch (Exception e) {
                reachable = false;
            } finally {
                if (socket != null)
                    try {
                        socket.close();
                    } catch (IOException e) {
                    }
            }
            
            if(reachable == true)
            	System.out.println(url);
        }
	}