Java 服务器未接收数据/客户端未发送数据

我正在制作一个聊天程序。问题发生在连接阶段。理论上，连接是这样发生的：

[服务器]接受（）传入连接

[客户端]尝试连接到服务器

[服务器和客户端]初始化IO

[客户端]发送带有后缀的用户名，该后缀指示是否有密码

[服务器]接收用户名，检查是否有传入密码（如果有，也请阅读）

[服务器]如果客户端已注册，则签入数据库

[服务器]。。。（多次检查客户账户等）

[服务器]如果客户机被接受或未被接受，则向客户机发送答复

[客户]接收并解释答案

请注意，步骤6和7尚未实现，服务器跳过直接创建新客户机帐户并在网络中接受它

现在，在第4步（如果错误来自客户端未发送其名称）或第5步（如果错误来自服务器未接收名称），在这两种情况下，服务器都无法等待客户端的名称，客户端无法等待服务器的答复（第9步）。我请求您帮助查找此错误的原因以及如何修复它

以下是服务器用于接受新连接的函数代码：

public void establishConnection() {
    Socket client = null;
    BufferedReader input = null;
    PrintWriter output = null;
    String name = null;
    String password = null;

    try {
        client = server.accept();
        System.out.println("A connection is being established");
        input = new BufferedReader(new InputStreamReader(client.getInputStream()));
        output = new PrintWriter(client.getOutputStream());

        //LOCATION OF THE BUG
        //DESCRIPTION: If the name has been sent, the server seems not to receive it.
        System.out.println("Waiting for the client's name...");
        name = input.readLine();
        if (name.charAt(name.length() - 1) == Keywords.PASSWORD) {
            System.out.println("Waiting for the client's password...");
            password = input.readLine();
        } else
            System.out.println("The client has no password");
        name = name.substring(0, name.length() - 1);

        System.out.println("Creation of the metaClient");
        MetaClient metaClient = new MetaClient(name);
        if (password != null)
            metaClient.setPassword(password);
        metaClient.setSocket(client);
        System.out.println("Activating listening thread");
        metaClient.activateCommunications(this, this);

        /* If there is no already registered clients,
         * the first to connect shall be the owner.
         */
        if (clientsList.size() == 0)
            metaClient.addRight(MetaClient.OWNER);

        clientsList.add(metaClient);

        output.write(Keywords.CONNECTION_ACCEPTED);
        System.out.println("The connection process of user " + metaClient.getName()
                + " is complete.");
    } catch (IOException e) {
        System.out.println("Error when establishing a new connection");
        e.printStackTrace();
    } finally {
        try {
            if (input != null)
                input.close();
            if (output != null)
                output.close();
        } catch (IOException e) {
            System.out.println("Error when closing the IO of the new connection.");
            e.printStackTrace();
        }
    }
}

以下是尝试连接到服务器的客户端生成器的代码：

public ChatClient(String ip, int port, String name, String password) throws ConnectException {
    this.name = name;
    boolean connectionRefused = false;
    try {
        System.out.println("Establishing connection to the server...");
        server = new Socket(ip, port);
        BufferedReader input = new BufferedReader(new InputStreamReader(server.getInputStream()));
        PrintWriter output = new PrintWriter(server.getOutputStream());

        //LOCATION OF THE BUG:
        //BUG DESCRIPTION: The name seems not to be sent to the server
        System.out.println("Sending name to the server...");
        if (password == null || password == "") {
            name += Keywords.NO_PASSWORD;
            output.println(name);
        } else {
            name += Keywords.PASSWORD;
            output.println(name);
            System.out.println("Sending password to the server...");
            output.println(password);
        }

        System.out.println("Waiting for the server's response...");
        //Wait for the server's response
        String response = input.readLine();
        if (response.equals(Keywords.CONNECTION_ACCEPTED))
            System.out.println("The connection has been accepted");
        else
            connectionRefused = true;
    } catch (IOException e) {
        System.out.println("Error when connecting to the server");
        e.printStackTrace();
        System.exit(1);
    }

    if (connectionRefused)
        throw new ConnectException("The connection was refused by the server");
    else {
        communication = new CommunicationProtocol(server, this, this);
        communication.start();
    }
}

任何帮助都将非常感谢，这让我花了相当长的时间来解决这个问题

编辑回答恐怖袋熊的评论：

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是的，一台机器运行服务器，另一台运行客户端。但是，即使两个程序在同一台机器上作为两个独立的程序运行，也会发生错误。

客户端和服务器是否在两个不同的进程/线程中？@ScaryWombat我对帖子进行了编辑，解释了它是如何运行的。简言之：是的。它们实际上在两个不同的应用程序中运行，一个用于最终用户，另一个用于网络所有者。抛出了什么错误？@ScaryWombat没有抛出错误，都只是一直等待对方的名称/答案。readLine（）是一个阻塞函数，它等待所有信息到达后再继续。如果您指的是客户端构造函数可以抛出的ConnectException，那么如果服务器拒绝连接，则会抛出该异常，通常是因为客户端已被禁止或是黑名单的一部分。