SocketExceptopn: Socket Operation on nonsocket: JVM_Bind - what ?

Question

Hi,
I'm a new Java-application developer. I'm stadying Java at university in Kassel (germany) an now in university holiday I wnat to development a little messanging tool. So I have tried some basic technics.... but the simplesed things won't work!
I've wrote this code:
import java.net.*;
import java.io.*;
class MulClient
public static void main( String args[] ) throws IOException
Socket server = new Socket("localhost", 450 );
But if I complie the code an run it....the JVM throws an Exception:
Exception in thread "main" java.net.SocketException: Socket operation on nonsocket: JVM_Bind
at java.net.PlainSocketImpl.socketBind(Native Method)
at java.net.PlainSocketImpl.bind(PlainSocketImpl.java:359)
at java.net.Socket.bind(Socket.java:553)
at java.net.Socket.<init>(Socket.java:363)
at java.net.Socket.<init>(Socket.java:178)
at MulClient.main(MulClient.java:8)
I'm using windows xp Sp1 an a firewall (kerio personal firewall), ie 6 sp1....I'm behind a router but protocolls such as TCP/ip are installed..of course....
Excause me bad english.....
Thanks!
Faithfully MrSandman

Answer 1

Hi,
1) You haven't created a ServerSocket so nothing's
listening on that port. I doubt this is it, as it
would probabl time out.If I start the server class-file (changed port 1044):
import java.net.*;
import java.io.*;
public class MulServer
  public static void main( String args[] ) throws IOException
    ServerSocket server = new ServerSocket( 1044 );
     while ( true )
      Socket client = server.accept();
      InputStream  in  = client.getInputStream();
      OutputStream out = client.getOutputStream();
      int start = in.read();
      int end = in.read();
      int result = start * end;
      out.write( result );
      client.close();
}the same exception appears. So there can't be a server listining on that port. But why doesn't this work?
on MS developers page the exception or winsocket error is explained:
"An operation was attempted on something that is not a socket. Either the socket handle parameter did not reference a valid socket, or for select, a member of an fd_set was not valid."
But I don't understand; what does this mean?
2) There is a server/listener type dealy bound to
that port, but it's a FIFO or named pipe or
something, rather than a Socket.What? do you think there is another application running on that port. There isn't anyone.
I can't believe. I've tried another network-sample file taken from an internet tutorial...(I thought...this should work...) but the same exception....
Any ideas? Please help!
Thanks MrSandman