UnknownHostException?

[gautam89]

Hi,

I'm sorry if this sort of question has been answered before. I've looked through many of the threads pertaining to sockets, but was not able to find where I was going wrong.

I need to create a program that can communicate with another PC on the same LAN network for my computer science project. When I run the client program I get the following error:

Exception in thread "main"

java.net.UnknownHostException: GAUTAM-LAPTOP
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 tcpclient.main(tcpclient.java:12)

I'm running the server program on a laptop with name GAUTAM-LAPTOP. I've configured my router to direct port 1234 (TCP) to GAUTAM-LAPTOP as well.

Below is the server code I am using:

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

public class tcpserver
{
	public static void main(String args[]) throws Exception
	{
		String	message;
		String	messageout;
		ServerSocket ssock = new ServerSocket(1234);
		while(true)
		{
			Socket	connsock = ssock.accept();
			InputStreamReader instr =  
				new InputStreamReader(connsock.getInputStream());
			DataOutputStream outstr = 
				new DataOutputStream(connsock.getOutputStream());
			BufferedReader innet = new BufferedReader(instr);
			message = innet.readLine();
			messageout = message.toUpperCase() + "\n";
			outstr.writeBytes(messageout);
		}
	}
}

Below is the client code I am using:

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

public	class	tcpclient	
{
	public	static	void	main(String[] args) throws Exception
	{
		String	message;
		String	modifiedmessage;
		BufferedReader inkbd = 
			new BufferedReader(new InputStreamReader(System.in));
		Socket	csock = new Socket("GAUTAM-LAPTOP",1234);
		DataOutputStream out = 
			new DataOutputStream(csock.getOutputStream());
		BufferedReader innet = 
			new BufferedReader(new InputStreamReader(csock.getInputStream()));
		message = inkbd.readLine();
		out.writeBytes(message + "\n");
		modifiedmessage = innet.readLine();
		System.out.println("Server sent :- " + modifiedmessage);
		csock.close();
	}
}

Can someone please give me some guidance as to what I am doing wrong and why the error is coming? Also, is there an easier way to implement this - I only need it for communication between computers on the same network.

[henry_78]

I think u have a problem with translating your lap-top name in an IP address..try to modify your hosts file adding an entry with your lap-top name and ip