How work with socket and hostnames in Java? - sockets

Question

Recently I had to change my router, it was an Belking for one D-Link, my program worked it with my Belkin router but not now with the D-Link router.
Here is my program:
The client:
package brainset.socket;
import java.io.IOException;
import java.io.PrintStream;
import java.net.Socket;
/**
*
* #author Valter
*/
public class Client {
public static void main(String[] args) {
Socket s = null;
PrintStream ps = null;
try{
s = new Socket("valterhenrique.dyndns.info", 40000);
ps = new PrintStream(s.getOutputStream());
ps.println("lamp");
}catch(IOException e){
System.out.println("Some problem happens.");
e.printStackTrace();
}finally{
try{
s.close();
}catch(IOException e){}
}
}
}
And here's my server:
package brainset.socket;
// imports
public class Server {
private Supervisory supervisory;
public Server(Supervisory supervisory) {
this.supervisory = supervisory;
}
public void start() {
ThreadServer ts = new ThreadServer();
Thread t = new Thread(ts);
t.start();
}
class ThreadServer extends Thread {
public void run() {
ServerSocket ss = null;
Socket socket = null;
BufferedReader br = null;
try {
ss = new ServerSocket(40000);
socket = ss.accept();
br = new BufferedReader(new InputStreamReader(socket.getInputStream()));
String message;
while ((message = br.readLine()) != null) {
System.out.println("message:" + message);
try {
if (message.equals("lamp")) {
supervisory.active();
supervisory.switchLamp();
} else if (message.contains("airConditioning")) {
String airConditioning[] = message.split(":");
// temperature[0] = 'temperature'
// temperature[1] = temperature value
supervisory.active();
supervisory.changeTemperature(Float.parseFloat(airConditioning[1]));
}
} catch (Exception ex) {
Logger.getLogger(Server.class.getName()).log(Level.SEVERE, null, ex);
}
socket = ss.accept();
br = new BufferedReader(new InputStreamReader(socket.getInputStream()));
}
} catch (IOException ioe) {
ioe.printStackTrace();
} finally {
try {
socket.close();
ss.close();
} catch (IOException ioe) {
ioe.printStackTrace();
}
}
}
}
public static void main (String args[]){
Server s = new Server(new Supervisory("192.168.1.149", "192.168.1.255", 101));
s.start();
}
}
I already opened a port in my new router and update the hostname in DynDns.org but still keeping launching an exception:
java.net.ConnectException: Connection refused: connect
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:351)
at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:213)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:200)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
at java.net.Socket.connect(Socket.java:529)
at java.net.Socket.connect(Socket.java:478)
at java.net.Socket.<init>(Socket.java:375)
at java.net.Socket.<init>(Socket.java:189)
at brainset.socket.Client.main(Client.java:28)
If I change the hostname 'valterhenrique.dyndns.info' it works, but this is not what I want, I want to works with the hostname because I'm in a dynamic ip network.
Any idea ?

Answer 1

I think you need permit external access to your network. In the Port Forwarding page (in the router's configuration page) add a entry that forwards the external requests to a specific address in your LAN.