Java-套接字編程-如何使客戶端從多個服務器接收消息？

Question

我需要讓多個客戶端與多個服務器對話並處理它們的響應。

到目前為止，我已經能夠編寫綁定到多個客戶端的服務器代碼（為每個客戶端生成一個線程），並且客戶端連接到多個服務器。

我遇到問題的地方是客戶端-我無法從服務器接收響應。

操作順序如下-

假設我有2台服務器和1個客戶端。 客戶端連接到兩台服務器，向它們發送消息，兩台服務器都接收到該消息，並且都向客戶端發送回復-我無法收到此回復。

服務器代碼-

 @Override
  public void run() {
    try {

      // create a serversocket to listen to requests
      ServerSocket serverSocket = new ServerSocket(port);

      // create n sockets to listen to 5 client
      for (int i = 0; i < n; i++) {
        Socket socket = serverSocket.accept();
        // create a processor thread for each to read and process the incoming Messages
        Processor processor = new Processor(socket);
        processor.start();
      }

     serverSocket.close();
    } catch (IOException e) {
      e.printStackTrace();
    }

服務器代碼處的處理器-

@Override
  public void run() {
    try {
      ObjectInputStream in = new ObjectInputStream(socket.getInputStream());
      OutputStreamWriter out = new OutputStreamWriter(socket.getOutputStream());

      while (true) {
        String str = in.readObject();

        System.out.println(message);

        out.write("Got your message " + message.toString());

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

    System.out.println("Processor completed " );
  }

客戶代碼-

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

    // make the connections with other nodes
    connections = connect();

    // connect() creates connections from the client to all servers and stores the socket and out objects in the object called Connections.Code omitted to avoid clutter

    // process all the commands 
    while(!commands.isEmpty()){

      for(int i=0 ; i<2; i++){
      send(commands.poll() , i);

    }

      Thread.sleep(500);
    }

  }


  // Sends Message m to the node i
  public static synchronized void send(Message m, int i) {
    try {
      connections.outs[i].writeInt(m.nodeId);
      connections.outs[i].writeInt(m.timestamp);
      connections.outs[i].writeObject(m.type);
      connections.outs[i].writeObject(m.value);
      connections.outs[i].flush();

      InputStreamReader isr = new       InputStreamReader(connections.sockets[i].getInputStream());
      final BufferedReader br = new BufferedReader(isr);

      new Thread() {
        public void run() {
          try {
            while (true) {
              String message = br.readLine();
              System.out.println("Message received from the server : " +message);
            }
          } catch(IOException e) {
            e.printStackTrace();
          }
        }
      }.start();

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

我確定在收聽消息時我做錯了什么。 關於如何從多個服務器接收和處理消息的任何建議都將非常有幫助。

TIA

Answer 1

我面臨兩個問題：

1.您沒有沖洗。

out.write（“收到您的消息” + message.toString（））;

2.在服務器中，您不發送\\ n

問題是方法readLine

  new Thread() {
    public void run() {
      try {
        while (true) {
          String message = br.readLine();
          System.out.println("Message received from the server : " +message);
        }
      } catch(IOException e) {
        e.printStackTrace();
      }
    }
  }.start();

來自文檔 ：

讀取一行文本。 一行被認為由換行符（'\\ n'），回車符（'\\ r'）或回車符后緊跟換行符之一終止。

但是服務器既不發送\\ n也不發送\\ r。 嘗試

  out.write("Got your message " + message.toString() + "\n");