[Java] Socket: ConnectException

[Patrick Jane]

Ciao a tutti,

non ho mai smanettato con i Socket, così ho ripreso la parte del libro che ne parlava e mostrava questo esempio..

import java.io.*;
import java.net.*;

class Whois {
  public static void main(String args[]) throws Exception {
    int c;
	Socket s = new Socket("internic.net",43);
	InputStream in = s.getInputStream();
	OutputStream out = s.getOutputStream();
	String str = (args.length == 0 ? "mcgraw-hill.com" : args[0]) + "\n";
	byte[] buf = str.getBytes();
	out.write(buf);
	while((c = in.read()) != -1) {
	  System.out.println((char) c);
	}
	
	s.close();
  }
}

Al momento dell'esecuzione ottengo:

Exception in thread "main" java.net.ConnectException: Connection refused: connec
t
        at java.net.PlainSocketImpl.socketConnect(Native Method)
        at java.net.PlainSocketImpl.doConnect(Unknown Source)
        at java.net.PlainSocketImpl.connectToAddress(Unknown Source)
        at java.net.PlainSocketImpl.connect(Unknown Source)
        at java.net.SocksSocketImpl.connect(Unknown Source)
        at java.net.Socket.connect(Unknown Source)
        at java.net.Socket.connect(Unknown Source)
        at java.net.Socket.<init>(Unknown Source)
        at java.net.Socket.<init>(Unknown Source)
        at Whois.main(Whois.java:7)

Per qual motivo?

Grazie! ^^