public static void main(String[] args) {
try {
Socket s1 = new Socket("127.0.0.1", 57643);
InputStream is = s1.getInputStream();
DataInputStream dis = new DataInputStream(is);
System.out.println(dis.readUTF());
OutputStream os = s1.getOutputStream();
DataOutputStream dos = new DataOutputStream(os);
dos.writeUTF("Oh my gosh...");
dis.close();
is.close();
dos.close();
os.close();
s1.close();
} catch (ConnectException connExc) {
connExc.printStackTrace();
System.out.println("Server connection failed");
} catch (IOException ioExc) {
ioExc.printStackTrace();
}
}
/**
* Initialize a server on the given port. This server will not listen until it is launched with
* the start() method.
*
* @param port
* @throws IOException
*/
public Server(int port, int botPort, Retriever ret, Map<String, Double> traffic)
throws IOException {
if (port <= 1024 || botPort <= 1024) {
throw new IllegalArgumentException("Ports under 1024 are reserved!");
}
_port = port;
_clients = new ClientPool();
_socket = new ServerSocket(port);
try {
_botSocket = new Socket("localhost", botPort);
_botConnectionSuccess = true;
_trafficInput = new BufferedReader(new InputStreamReader(_botSocket.getInputStream()));
_trafficData = traffic;
} catch (ConnectException e) {
System.out.println("unable to connect");
System.out.println(e.getMessage());
_botConnectionSuccess = false;
}
r = ret;
}
public static void main(String[] args) {
int retry = 2;
int port = 123;
int timeout = 3000;
// get the address and NTP address request
InetAddress ipv4Addr = null;
try {
ipv4Addr = InetAddress.getByName("133.100.11.8");
} catch (UnknownHostException e1) {
e1.printStackTrace();
return;
}
int serviceStatus = -1;
DatagramSocket socket = null;
long responseTime = -1;
try {
socket = new DatagramSocket();
socket.setSoTimeout(timeout); // will force the InterruptedIOException
for (int attempts = 0; attempts <= retry && serviceStatus != 1; attempts++) {
try {
// Send NTP request
byte[] data = new NtpMessage().toByteArray();
DatagramPacket outgoing = new DatagramPacket(data, data.length, ipv4Addr, port);
long sentTime = System.currentTimeMillis();
socket.send(outgoing);
// Get NTP Response
// byte[] buffer = new byte[512];
DatagramPacket incoming = new DatagramPacket(data, data.length);
socket.receive(incoming);
responseTime = System.currentTimeMillis() - sentTime;
double destinationTimestamp = (System.currentTimeMillis() / 1000.0) + 2208988800.0;
// 这里要加2208988800，是因为获得到的时间是格林尼治时间，所以要变成东八区的时间，否则会与与北京时间有8小时的时差
// Validate NTP Response
// IOException thrown if packet does not decode as expected.
NtpMessage msg = new NtpMessage(incoming.getData());
double localClockOffset =
((msg.receiveTimestamp - msg.originateTimestamp)
+ (msg.transmitTimestamp - destinationTimestamp))
/ 2;
System.out.println(
"poll: valid NTP request received the local clock offset is "
+ localClockOffset
+ ", responseTime= "
+ responseTime
+ "ms");
System.out.println("poll: NTP message : " + msg.toString());
serviceStatus = 1;
} catch (InterruptedIOException ex) {
// Ignore, no response received.
System.out.println("InterruptedIOException: " + ex.getMessage());
}
}
} catch (NoRouteToHostException e) {
System.out.println("No route to host exception for address: " + ipv4Addr);
} catch (ConnectException e) {
// Connection refused. Continue to retry.
e.fillInStackTrace();
System.out.println("Connection exception for address: " + ipv4Addr);
} catch (IOException ex) {
ex.fillInStackTrace();
System.out.println("IOException while polling address: " + ipv4Addr);
} finally {
if (socket != null) socket.close();
}
// Store response time if available
if (serviceStatus == 1) {
System.out.println("responsetime==" + responseTime);
}
}
