JavaFX 和网络

Question

我是套接字和网络编程的新手，这是我尝试创建一个简单的聊天服务器，我的代码似乎没有任何问题(据我所知)，它编译得很好，但是当我尝试运行它时，它似乎卡住了，什么也没做。

很抱歉，如果已经有人问过这样的问题，我什么也没找到，但我不确定哪里出了问题，所以我真的不知道要寻找什么。

服务器:

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Date;

import javafx.scene.Scene;
import javafx.scene.control.TextArea;
import javafx.stage.Stage;

public class ChatServer extends Stage {
    TextArea informationArea = new TextArea();
    String message = null;

    public ChatServer() {
        informationArea.setEditable(false);
        setTitle("Chat Server");
        setScene(new Scene(informationArea, 500, 300));
        show();

        try {
            ServerSocket serverSocket = new ServerSocket(8000);
            informationArea.appendText("Server started at " + new Date() + '\n');

            int clientNumber = 1;

            while(true) {
                Socket socket = serverSocket.accept();
                InetAddress inetAddress = socket.getInetAddress();

                informationArea.appendText(
                    "Client: " + clientNumber++
                    + "\n\thost name: " + inetAddress.getHostName()
                    + "\n\tIP address " + inetAddress.getHostAddress() + "\n\n"
                );

                ClientHandler task = new ClientHandler(socket);
                new Thread(task).start();
            }
        } catch(IOException ex) {
            System.err.println(ex);
        }
    }

    class ClientHandler implements Runnable {
        private Socket socket;

        ClientHandler(Socket socket) {
            this.socket = socket;
        }

        @Override
        public void run() {
            try {
                DataInputStream inputFromClient = new DataInputStream(socket.getInputStream());
                DataOutputStream outputToClient = new DataOutputStream(socket.getOutputStream());

                while (true) {
                    if (message != null) {
                        outputToClient.writeUTF(message);
                    }
                    message = inputFromClient.readUTF();
                }
            } catch(IOException e) {
                System.err.println(e);
            }
        }
    }
}

运行它的类:

import javafx.application.Application;
import javafx.stage.Stage;

public class RunChatServer extends Application {
    public static void main(String[] args) {
        launch(args);
    }

    @Override
    public void start(Stage stage) {
        stage = new ChatServer();
    }
}

如果您能提供有关问题所在和原因、实现此目标的正确方法以及任何风格建议的意见，我将不胜感激，因为这是我的第一次尝试，我不知道实现此目标的传统方法。

更新:我认为这可能与阻止 UI 线程有关，我添加了 import javafx.concurrent.Task 并像这样重构了我的 ClientHandler 类:

class ClientHandler extends Task {
        private Socket socket;

        ClientHandler(Socket socket) {
            this.socket = socket;
        }

        @Override
        public Void call() {
            try {
                DataInputStream inputFromClient = new DataInputStream(socket.getInputStream());
                DataOutputStream outputToClient = new DataOutputStream(socket.getOutputStream());

                while (true) {
                    if (message != null) {
                        outputToClient.writeUTF(message);
                        outputToClient.flush();
                    }
                    message = inputFromClient.readUTF();
                }
            } catch(IOException e) {
                System.err.println(e);
            }
            return null;
        }
    }

但这并没有解决任何问题......

Answer 1

将服务器接受套接字的循环放在它自己的线程中，而不是阻塞构造函数。

    try {
        ServerSocket serverSocket = new ServerSocket(8000);
        informationArea.appendText("Server started at " + new Date() + '\n');

        new Thread(() -> {
            int clientNumber = 1;
            while (true) {
                try {
                    Socket socket = serverSocket.accept();
                    InetAddress inetAddress = socket.getInetAddress();

                    Platform.runLater(() -> 
                        informationArea.appendText(
                            "Client: " + clientNumber++
                            + "\n\thost name: " + inetAddress.getHostName()
                            + "\n\tIP address " + inetAddress.getHostAddress() + "\n\n"
                        )
                    );

                    ClientHandler task = new ClientHandler(socket);
                    new Thread(task).start();
                } catch (IOException ex) {
                    Logger.getLogger(ChatServer.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
        }).start();

    } catch (IOException ex) {
        System.err.println(ex);
    }