Java

Question

我需要让多个客户端与多个服务器通信并处理来自它们的响应。

到目前为止，我已经能够编写绑定到多个客户端的服务器代码（为每个客户端生成一个线程）并且客户端连接到多个服务器。

我遇到问题的地方是在客户端 - 我无法从服务器接收响应。

操作顺序如下-

假设我有 2 个服务器和 1 个客户端。客户端连接到两台服务器，向它们发送消息，两台服务器都收到它并都向客户端发送回复 - 我无法收到此回复。

服务器代码-

 @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();
    }

服务器代码处的处理器 -

@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 " );
  }

客户端代码-

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();
    }
  }

我确定我在听消息时做错了什么。任何有关如何从多个服务器接收和处理消息的建议都会非常有帮助。

TIA

Answer 1

我面临两个问题：

1。你没有冲水。

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

2。在服务器中你没有发送 \n

问题出在方法上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();

来自 Documentation:

Reads a line of text. A line is considered to be terminated by any one of a line feed ('\n'), a carriage return ('\r'), or a carriage return followed immediately by a linefeed.

但是服务器既不发送\n也不发送\r。尝试

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

Java - 套接字编程 - 如何让客户端从多个服务器接收消息？

Java - Socket Programming - How can I make a client receive msg from multiple servers?

sockets

serversocket

1。你没有冲水。

2。在服务器中你没有发送 \n