如何使服务器能够接受来自具有不同套接字连接的客户端的多个输入流？

Question

I'm trying to create a simple chat server that allows multiple distinct clients to chat with one another via the server output console. The clients each with their own thread write to the server and can view the results on the server's standard output via the console. However, I can't seem to get the BufferedReader to receive the messages coming from more than one client socket connection.

Currently the first client thread gains exclusive access to the BufferedReader via it's socket. However, I'd like multiple clients to connect to the server's input stream reader and have it wait for input from multiple client threads with distinct socket connections. I would like clients to be able to post to the server at the same time. How would I accomplish this with or without BufferedReader as my input stream reader?

public class chatServer {

    public chatServer() throws IOException {

        int PORT = 8189;

        try (ServerSocket server = new ServerSocket(PORT)) {
            System.out.println("The server is running at "
                    + InetAddress.getByName(null) + "...");
            String rules = "The rules of this server are as follows:\n"
                    + "1.Respect your fellow chatters\n"
                    + "2.Vulgar language will result in punishment\n"
                    + "3.We reserve the right to ban you at any time.\n"
                    + "Enjoy!";

            System.out.println(rules + "\n");

            while (true) {
                try {
                    new clientHandler(server.accept()).run();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }

    public static void main(String[] args) throws IOException {
        chatServer cs = new chatServer();
    }

    class clientHandler implements Runnable {

        Socket socket;

        public clientHandler(Socket socket) {
            this.socket = socket;
        }

        public void run() {

            try {
                BufferedReader in = new BufferedReader(new InputStreamReader(
                        socket.getInputStream()));

                String line;
                while (true) {
                    line = in.readLine();
                    if ((line == null) || line.equalsIgnoreCase("exit")) {
                        // socket.close();
                    } else {
                        System.out.println(socket.getPort() + " > " + line);
                    }
                }

            } catch (IOException e) {
                e.printStackTrace();
            } catch (Exception e) {
                e.printStackTrace();
            }

        }

    }
}

---

public class chatClient {

    private Socket socket;
    private String name = "";   
    private String IP = "127.0.0.1";
    private int PORT = 8189;


    public chatClient(String name, String IP, int PORT) throws UnknownHostException, IOException{

        this.name = name;
        socket = new Socket(this.IP,this.PORT);

    }

    public static void main(String[] args) throws UnknownHostException, IOException{

        chatClient c1 = new chatClient("John",null,0);
        chatClient.connect(c1);

    }

    public static void connect(chatClient cc) throws IOException {

        Socket socket = cc.socket; 
        PrintWriter out = new PrintWriter(socket.getOutputStream(), true);
        out.println("Welcome " + cc.name);

        String message = "";
        boolean done = false;
        Scanner stdin = new Scanner(System.in);
        System.out.println("Type your message here:");

        while(!done){
        System.out.print("> ");
        message = stdin.nextLine();
        out.println(message);

        if(message.trim().equalsIgnoreCase("exit")){
            done = true;
        }

        }
    }

}

Update: I'm looking for a suitable/alternative method to achieve the functionality of a Server that accepts multiple posts from various clients with distinct socket connections? If my current implementation cannot do so then how may I modify it to do so?

Answer 1

A BufferedReader is constructed around a single reader, which in turn is directly or indirectly connected to a single data source. There is no way of changing that once constructed.

In short your question doesn't make sense. Each client has a distinct socket, which in turn has its unique input and out out streams, which in turn must be wrapped in a distinct BufferedTeader per client. Not one shared between all clients.

EDIT Your actual problem has nothing to do with BufferedReaders . It is here:

new clientHandler(server.accept()).run();

You're running the handler inline instead of as a separate thread. run() should be

new Thread(new clientHandler(socket.accept())).start();