Java Chat Server running on PC command line

The former post show how to "Implement simple Android Chat Application, server side" running on Android. Actually, it show info of IP/Port only, without any user interaction. This post is another command line version of the Chat Server in Java, it can run on PC's ommand Line. It can connected with "Simple Android Chat Application, client side".

The video show it was compiled with SDK 8, and run on command line, at PC running Ubuntu Linux.


JavaCmdChatServer.java

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.InetAddress;
import java.net.NetworkInterface;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.SocketException;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;

public class JavaCmdChatServer {

    static final int SocketServerPORT = 8080;

    String msgLog = "";

    List<ChatClient> userList;

    ServerSocket serverSocket;

    public static void main(String[] args) {
        JavaCmdChatServer ChatServer = new JavaCmdChatServer();

        while (true) {
        }
    }

    JavaCmdChatServer() {
        System.out.print(getIpAddress());
        userList = new ArrayList<>();
        ChatServerThread chatServerThread = new ChatServerThread();
        chatServerThread.start();

    }

    private class ChatServerThread extends Thread {

        @Override
        public void run() {
            Socket socket = null;

            try {
                serverSocket = new ServerSocket(SocketServerPORT);
                System.out.println("I'm waiting here: "
                    + serverSocket.getLocalPort());
                    System.out.println("CTRL + C to quit");

                while (true) {
                    socket = serverSocket.accept();
                    ChatClient client = new ChatClient();
                    userList.add(client);
                    ConnectThread connectThread = new ConnectThread(client, socket);
                    connectThread.start();
                }

            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                if (socket != null) {
                    try {
                        socket.close();
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }
            }

        }

    }

    private class ConnectThread extends Thread {

        Socket socket;
        ChatClient connectClient;
        String msgToSend = "";

        ConnectThread(ChatClient client, Socket socket) {
            connectClient = client;
            this.socket = socket;
            client.socket = socket;
            client.chatThread = this;
        }

        @Override
        public void run() {
            DataInputStream dataInputStream = null;
            DataOutputStream dataOutputStream = null;

            try {
                dataInputStream = new DataInputStream(socket.getInputStream());
                dataOutputStream = new DataOutputStream(socket.getOutputStream());

                String n = dataInputStream.readUTF();

                connectClient.name = n;

                msgLog = connectClient.name + " connected@"
                    + connectClient.socket.getInetAddress()
                    + ":" + connectClient.socket.getPort() + "\n";

                System.out.println(msgLog);

                dataOutputStream.writeUTF("Welcome " + n + "\n");
                dataOutputStream.flush();

                broadcastMsg(n + " join our chat.\n");

                while (true) {
                    if (dataInputStream.available() > 0) {
                        String newMsg = dataInputStream.readUTF();

                        msgLog = n + ": " + newMsg;
                        System.out.print(msgLog);
                        broadcastMsg(n + ": " + newMsg);
                    }

                    if (!msgToSend.equals("")) {
                        dataOutputStream.writeUTF(msgToSend);
                        dataOutputStream.flush();
                        msgToSend = "";
                    }

                }

            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                if (dataInputStream != null) {
                    try {
                        dataInputStream.close();
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }

                if (dataOutputStream != null) {
                    try {
                        dataOutputStream.close();
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }

                userList.remove(connectClient);

                System.out.println(connectClient.name + " removed.");

                msgLog = "-- " + connectClient.name + " leaved\n";
                System.out.println(msgLog);

                broadcastMsg("-- " + connectClient.name + " leaved\n");

            }

        }

        private void sendMsg(String msg) {
            msgToSend = msg;
        }

    }

    private void broadcastMsg(String msg) {
        for (int i = 0; i < userList.size(); i++) {
            userList.get(i).chatThread.sendMsg(msg);
            msgLog = "- send to " + userList.get(i).name + "\n";
            System.out.print(msgLog);
        }
        System.out.println();
        
    }

    private String getIpAddress() {
        String ip = "";
        try {
            Enumeration<NetworkInterface> enumNetworkInterfaces = NetworkInterface
                .getNetworkInterfaces();
            while (enumNetworkInterfaces.hasMoreElements()) {
                NetworkInterface networkInterface = enumNetworkInterfaces
                    .nextElement();
                Enumeration<InetAddress> enumInetAddress = networkInterface
                    .getInetAddresses();
                while (enumInetAddress.hasMoreElements()) {
                    InetAddress inetAddress = enumInetAddress.nextElement();

                    if (inetAddress.isSiteLocalAddress()) {
                        ip += "SiteLocalAddress: "
                            + inetAddress.getHostAddress() + "\n";
                    }

                }

            }

        } catch (SocketException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            ip += "Something Wrong! " + e.toString() + "\n";
        }

        return ip;
    }

    class ChatClient {

        String name;
        Socket socket;
        ConnectThread chatThread;

    }

}

Download the files.