Thread: Socket Programming

I have been going through java networking tutorials though not sure what to connect to, e.g. If I'm on my laptop what can I connect to that will give me permission, I don't want to connect to something I shouldn't. tutorials don't give real IP address and ports that would help me practice so not sure what to do.

I know it's a stupid question, would appreciate any replies.

Thank you, I'm still somewhat confused though have an outline of what you mean, I still need practice writing java program's though I'm finding networking quite interesting so I'm getting sidetracked.I'll keep trying, if you know any good networking resources that you have found helpful, specific to java other than sun tutorials please do recommend.

--- Update ---

Local host didn't work neither so very confused now, do you think I should learn to setup a network so I can get a better understand of how it works as now I'm clueless, though I don't want to end up screwing up my Internet or phone connection.

In that case post the code you are having problems with (or a shortened version). Something is out of order somewhere it seems.

I found the following code on the net from a person who got it working on his local host though not on ip.

import java.io.*;
import java.net.*;
 
 
public class ServerTest{
	public static void main(String[] args){
		final int PORT_NUMBER = 8089;
		while(true){
			try{
				ServerSocket serversock = new ServerSocket(PORT_NUMBER);
				System.out.println("LITSENING.....");
 
				Socket clientSock = serversock.accept();
				System.out.println("Connected Client");
				BufferedReader br = new BufferedReader(new InputStreamReader(clientSock.getInputStream()));
				System.out.println(br.readLine());
				br.close();
				serversock.close();
				clientSock.close();
			}catch(Exception e){
				e.printStackTrace();
			}
		}
	}
 
}

import java.net.*;
import java.io.*;
public class ClientTest{
  public static void main(String [] args)throws IOException{
	   final int PORT_NUMBER = 8089;
	   final String HOSTNAME = "127.0.0.1";
	   try{
		   Socket sock = new Socket(HOSTNAME,PORT_NUMBER);
		   PrintWriter out = new PrintWriter(sock.getOutputStream(),true);
		   out.println("test");
		   out.flush();
		   out.close();
		   sock.close();
 
	   }catch(Exception e){
		   e.printStackTrace();
	   }
  }
}

I can't get it working on local or otherwise.

I've got the exercise on sun networking tutorial to work so now need to spend more time on how it works. Is there any way I can explore my network connection similar to exploring files by opening, closing, creating and deleting directories etc. I can't seem to find anything online saying that this can be done so not sure, it would give me more of an understanding of my network and how it works.
I took note of how you said run server first then client, Thank you.

In java, two sockets can be connected by client and server programming. Server socket in server side listens to the TCP port and the client sends the data request through this socket.