Java Networking Problem: java.net.ConnectException: Connection refused: connect

I am unable to do any networking in Java when i run a simple networking program i am unable to get a connection, even when using the local host, The Error:

java.net.ConnectException: Connection refused: connect
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 EchoClient.main(EchoClient.java:8)

This is the program:

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

public class EchoClient{
    public static void main(String[] args) {
        try{
            Socket client = new Socket(InetAddress.getLocalHost(), 1234);
            InputStream clientIn = client.getInputStream();
            OutputStream clientOut = client.getOutputStream();
            PrintWriter pw = new PrintWriter(clientOut);
            BufferedReader br = new BufferedReader(new InputStreamReader(clientIn));
            Scanner stdIn = new Scanner(System.in);
            System.out.println("Input Message:");
            pw.println(stdIn.nextLine(开发者_如何学C));
            System.out.println("Recieved Message:");
            System.out.println(br.readLine());
            pw.close();
            br.close();
            client.close();
        }catch(Exception e){
            e.printStackTrace();
        }
    }
}

I use windows 7, i have turned of windows firewall and i dont have an anti virus.

As I wrote in my comment, check that the server (something like EchoServer?) is up and running.

But there are other problems when you succeed connecting. pw.println(stdIn.nextLine()); might not send the content to the server, you need to do a pw.flush(); to really send the content or you can create your PrintWriter with autoflushing:

 pw = new PrintWriter(clientOut, true);

If you need a EchoServer I just wrote one that works with your client if you add the flushing that I described above:

public class EchoServer {
    public static void main(String[] args) throws IOException {
        ServerSocket ss = new ServerSocket(1234);

        while (true) {
            // accept the connection 
            Socket s = ss.accept();

            try {
                Scanner in = new Scanner(s.getInputStream());
                PrintWriter out = new PrintWriter(s.getOutputStream(), true);

                // read a line from the client and echo it back
                String line;
                while ((line = in.nextLine()) != null) 
                    out.println(line);

            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                s.close();
            }
        }
    }
}

You can try it with telnet localhost 1234.

Double check that your local EchoServer is up and running on port 1234. If there is no server operating on that port, you won't be able to connect.

My solution in Windows 7 was to turn on "Simple TCP/IP Services". It's described here: http://www.windowsnetworking.com/articles_tutorials/windows-7-simple-tcpip-services-what-how.html