Java套接字swingWorker正在运行，但未接收或发送任何消息

Question

几天前，我尝试创建一个服务器-
客户端或客户端服务器，作为实验来学习使用线程的套接字，但后来有人告诉我应该使用swingWorker。我研究了如何使用它，并在实践中实现了它，但是它仍然不起作用。即使我获得连接并使用了.excute（），swingWorker线程也似乎没有运行。如果你们能帮我找出我做错的地方，那将是很好的。SwingWorker类位于startSever（）和startClient（）方法中。

    private void startServer() {
        SwingWorker <Void, String> runningServer = new SwingWorker<Void, String>(){
        protected Void doInBackground() {
            try {
                listeningSocket = new ServerSocket(port);
                System.out.println("waiting for connection");
                connection = listeningSocket.accept();
                connected = true;
                System.out.println("Connected");
                String incomeMessage =null;
                while(connected){
                inStream = connection.getInputStream();
                    inDataStream = new DataInputStream(inStream);
                    if (myMessage !=null){
                        outStream = connection.getOutputStream();
                        outDataStream = new DataOutputStream(outStream);
                    outDataStream.writeUTF(myMessage);
                    }

                    if((incomeMessage = inDataStream.readUTF())!=null){
                        clientMessage = incomeMessage;
                        publish(clientMessage);
                        incomeMessage =null;
                    }
                }
            } catch (IOException e) {
                clientMessage = "Connection Lost";
            }
        return null;
    }           
runningServer.execute();
}

Answer 1

这是一个非常基本的例子。

基本上，由于您的程序需要异步通信（也就是说，您需要能够从套接字读取并同时对其进行写入），因此需要将每个流卸载到单独的线程中。

很好，此示例的管理过程不存在。实际上，您应该具有某种“连接”管理器，该管理器可以干净地关闭输出和输入线程，以便例如，当用户键入“再见”时，输出线程将能够告诉连接管理器：连接应终止。然后它将告诉输入线程停止读取任何新消息并终止…

客户

public class Client {

    public static void main(String[] args) {

        try {
            Socket master = new Socket("localhost", 8900);
            new Thread(new InputHandler(master)).start();
            new Thread(new OuputHandler(master)).start();
        } catch (Exception ex) {
            ex.printStackTrace();
        }

    }

    public static class InputHandler implements Runnable {

        private Socket socket;

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

        @Override
        public void run() {
            boolean commune = true;
            BufferedReader reader = null;
            try {
                reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
                while (commune) {
                    String text = reader.readLine();
                    System.out.println("\n<server> " + text);
                    if (text.toLowerCase().equals("bye")) {
                        commune = false;
                    }
                }
            } catch (Exception exp) {
                exp.printStackTrace();
            } finally {
                try {
                    reader.close();
                } catch (Exception e) {
                }
                try {
                    socket.close();
                } catch (Exception e) {
                }
            }
        }
    }

    public static class OuputHandler implements Runnable {

        private Socket socket;

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

        @Override
        public void run() {
            boolean commune = true;
            BufferedWriter writer = null;
            try {
                writer = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
                Scanner scanner = new Scanner(System.in);
                while (commune) {
                    System.out.print("> ");
                    String text = scanner.nextLine();
                    writer.write(text);
                    writer.newLine();
                    writer.flush();
                    if (text.equalsIgnoreCase("bye")) {
                        commune = false;
                    }
                }
            } catch (Exception exp) {
                exp.printStackTrace();
            } finally {
                try {
                    writer.close();
                } catch (Exception e) {
                }
                try {
                    socket.close();
                } catch (Exception e) {
                }
            }
        }
    }
}

服务器

public class Server {

    public static void main(String[] args) {

        try {
            ServerSocket master = new ServerSocket(8900);
            Socket socket = master.accept();
            new Thread(new InputHandler(socket)).start();
            new Thread(new OuputHandler(socket)).start();
        } catch (Exception ex) {
            ex.printStackTrace();
        }

    }

    public static class InputHandler implements Runnable {

        private Socket socket;

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

        @Override
        public void run() {
            boolean commune = true;
            BufferedReader reader = null;
            try {
                reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
                while (commune) {
                    String text = reader.readLine();
                    System.out.println("\n<client> " + text);
                    if (text.toLowerCase().equals("bye")) {
                        commune = false;
                    }
                }
            } catch (Exception exp) {
                exp.printStackTrace();
            } finally {
                try {
                    reader.close();
                } catch (Exception e) {
                }
                try {
                    socket.close();
                } catch (Exception e) {
                }
            }
        }
    }
    public static class OuputHandler implements Runnable {

        private Socket socket;

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

        @Override
        public void run() {
            boolean commune = true;
            BufferedWriter writer = null;
            try {
                writer = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
                Scanner scanner = new Scanner(System.in);
                while (commune) {
                    System.out.print("> ");
                    String text = scanner.next();
                    writer.write(text);
                    writer.newLine();
                    writer.flush();
                    if (text.equalsIgnoreCase("bye")) {
                        commune = false;
                    }
                }
            } catch (Exception exp) {
                exp.printStackTrace();
            } finally {
                try {
                    writer.close();
                } catch (Exception e) {
                }
                try {
                    socket.close();
                } catch (Exception e) {
                }
            }
        }
    }
}

更新（抱怨）

当我眼前出现您的源代码时…

应该很少需要做 textMessage.addKeyListener(this)

因为您使用JTextField，所以应该使用ActionListener。造成这种情况的原因有很多，但是对您而言，主要的原因是“接受”动作取决于外观。虽然大多数系统都Enter按“接受”的方式使用，但这并不是保证。

看看如何编写动作监听器以获取更多信息

鉴于您要执行的操作通常很复杂，因此+1是一个很好的整体尝试！