Question

Ok so I have constructed a working example of a client and server which can accept multiple client connections. My problem is is that I cannot connect a client which is not running the same internet connection as the one the server is being hosted on. Is this possible using server sockets?

Here is the code for my server:

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

public class MultipleSocketServer {

public static Socket connection;
public static String name = "Tyler's Server";
public static int limit = 2;
public static Thread[] clients = new Thread[limit];
public static int current = 0;
public static int port = 25565;
public static String[] connected = new String[limit];
public static ServerSocket socket;

public static void main(String[] args) {
    System.out.println("Server starting...");
    for(int i = 0; i < limit; i++) {
        connected[i] = "";
    }
    try {
        ServerSocket socket = new ServerSocket(port);
        while(true) {
            Socket connection = socket.accept();
            String ip = connection.getRemoteSocketAddress().toString().substring(1, 13);
            loop:
            for(int i = 0; i < connected.length; i++) {
                if(connected[0].equals(ip) || connected[1].equals(ip)) {
                    break loop;
                }else if(!connected[i].equals(ip)) {
                    connected[i] = ip;
                    MultiServer_Client client = new     MultiServer_Client(connection, i);
                    Thread run = new Thread(client);
                    run.start();
                    break loop;
                }
            }
        }
    } catch (IOException e1) {
        System.out.println("Could not bind server on: " + port);
        System.exit(-1);
    }
}
}

And here is the rest:

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

public class MultiServer_Client implements Runnable {

public String time;
public Socket client;
public StringBuffer process = new StringBuffer();

public BufferedInputStream inputStream;
public InputStreamReader reader;

public BufferedOutputStream outputStream;
public OutputStreamWriter writer;

public StringVis check = new StringVis("");
public StringChangeListener checkListener = new StringChangeListener() {
    public void textChanged(StringChangeEvent e) {
        System.out.println("Changed");
        write("Server recieved message...");
    }
};

public boolean connected = true;
public int ID;

public MultiServer_Client(Socket connection, int i) {
    client = connection;
    ID = i;
    try {
        //declare text input/output
        inputStream = new BufferedInputStream(client.getInputStream());
        reader = new InputStreamReader(inputStream);
        outputStream = new BufferedOutputStream(client.getOutputStream());
        writer = new OutputStreamWriter(outputStream, "US-ASCII");
    } catch (IOException e) {
        System.out.println("IOException: " + e);
    }
    System.out.println(MultipleSocketServer.connected[ID] + " connected...");
    write("Connected to " + MultipleSocketServer.name);
}

public void run() {
    while(connected) {
        read();
    }
    System.out.println("Disconnecting client...");
}

public void write(String authen) {
    try {
        time = new java.util.Date().toString();
        String message = time + ": " + authen + (char) 13;
        writer.write(message);
        writer.flush();
    } catch (IOException e) {
        connected = false;
        MultipleSocketServer.connected[ID] = "";
    }
}

public void read() {
    //read from client
    int character;
    process = new StringBuffer();
    try {
        while ((character = reader.read()) != 13) {
            process.append((char) character);
        }
        check.setText(process.toString());
        process.delete(0, process.length());
    } catch (IOException e) {
        connected = false;
        MultipleSocketServer.connected[ID] = "";
    }
}
}

Here’s the client code:

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

public class SocketClient {

public static String host = "69.182.134.79";
public static int port = 25565;

public static void main(String [] args) {
    StringBuffer imports = new StringBuffer();
    String time;
    System.out.println("Client starting...");

    try {
        //establish client
        InetAddress address = InetAddress.getByName(host);
        Socket connection = new Socket(address, port);

        BufferedOutputStream bos = new     BufferedOutputStream(connection.getOutputStream());
        OutputStreamWriter osw = new OutputStreamWriter(bos, "US-ASCII");

        BufferedInputStream bis = new     BufferedInputStream(connection.getInputStream());
        InputStreamReader isr = new InputStreamReader(bis, "US-ASCII");

        while(true) {
            Scanner scan = new Scanner(System.in);
            String message = scan.nextLine();

            //write to server
            time = new java.util.Date().toString();
            String process = host + ":" + port + " sent data at " +     time + ": " + message + (char) 13;
            osw.write(process);
            osw.flush();

            //read from server
            int c;
            while ((c = isr.read()) != 13) {
                imports.append((char) c);
            }
            System.out.println(imports);
            imports.replace(0, imports.length(), "");

            if(message.equals("--EXIT")) {
                connection.close();
            }
        }

    } catch (UnknownHostException e) {
        System.out.println("UnknownHostException: " + e);
    } catch (IOException e) {
        System.out.println("IOExcepion: " + e);
    }
}
}

Answer 1

Change

MultiServer_Client client = new MultiServer_Client(connection, i);

to

MultiServer_Client client = new MultiServer_Client(new Socket([Server IP], port), i);

This should work.