初学Java网络编程socket，为何我的服务器打不开？

Question

初学Java网络编程socket，写了个服务器，但是打不开，求指导。代码如下

 import java.io.*;
import java.net.*;
import java.util.*;
import javafx.application.Application;
import javafx.application.Platform;
import javafx.scene.Scene;
import javafx.scene.control.ScrollPane;
import javafx.scene.control.TextArea;
import javafx.stage.Stage;

public class Test2_2Server extends Application{
    //创建显示文本域
    private TextArea area = new TextArea();

    public void start(Stage primaryStage){
        area.setEditable(false);

        Scene scene = new Scene(new ScrollPane(area), 450,300);
        primaryStage.setTitle("Test2_2Server");
        primaryStage.setScene(scene);
        primaryStage.show();

        try {
            //创建一个服务器套接字
            ServerSocket serverSocket = new ServerSocket(8800);
            Platform.runLater(() ->
                area.appendText("Server started at " + new Date() + '\n'));

            int clientNo = 1;
            while (true){
                //监听
                Socket socket = serverSocket.accept();

                area.appendText("Starting thread for client " + clientNo + " at " + new Date() + '\n');

                //获取客户端地址
                InetAddress inetAddress = socket.getInetAddress();
                area.appendText("Client " + clientNo + "'s host name is " + inetAddress.getHostName() + '\n');
                area.appendText("Client " + clientNo + "'s IP Address is " + inetAddress.getHostAddress() + '\n');

                //创建进程
                HandleAClient task = new HandleAClient(socket);

                //开始运行
                new Thread(task).start();

                //客户端数加一
                clientNo++;
            }
        }
        catch(IOException ex) {
            System.err.println(ex);
        }


    }

    public static void main(String[] args) {
        launch(args);
    }

    //服务器端的任务类
    class HandleAClient implements Runnable{
        private Socket socket;

        public HandleAClient(Socket socket1){
            this.socket = socket1;
        }

        public void run(){
            try {
                //创建输入输出流
                DataInputStream inputFromClient = new DataInputStream(socket.getInputStream());
                DataOutputStream outputToClient = new DataOutputStream(socket.getOutputStream());

                while (true){
                    //获取客户端数据
                    double annualInterestRate = inputFromClient.readDouble();
                    int numberOfYears = inputFromClient.readInt();
                    double loanAmount = inputFromClient.readDouble();

                    //计算偿还额
                    double totalPayment = loanAmount * Math.pow(1 + annualInterestRate * 0.01, numberOfYears);
                    double monthlyPayment = totalPayment / numberOfYears / 12;
                    //将数据传送至客户端
                    outputToClient.writeDouble(monthlyPayment);
                    outputToClient.writeDouble(totalPayment);
                    //输出
                    Platform.runLater(() ->{
                        area.appendText("Annual Interest Rate:" + annualInterestRate + '\n');
                        area.appendText("Number Of Year:" + numberOfYears + '\n');
                        area.appendText("Loan Amount:" + loanAmount + '\n');

                        area.appendText("Monthly Payment:" + monthlyPayment + '\n');
                        area.appendText("Total Payment:" + totalPayment + '\n');
                    });
                }
            }
            catch (IOException ex) {
                ex.printStackTrace();
            }
        }
    }
} 

Answer 1

已经找到问题，问题出在JavaFX的application线程，需要给服务器也分配一个线程，否则两者会发生冲突，导致程序无法正常启动。
具体修改程序代码如下,由于有人说看起来太复杂，稍作删减：

import java.io.*;
import java.net.*;
import java.util.*;
import javafx.application.Application;
import javafx.application.Platform;
import javafx.scene.Scene;
import javafx.scene.control.ScrollPane;
import javafx.scene.control.TextArea;
import javafx.stage.Stage;

public class net extends Application{
    //创建显示文本域
    private TextArea area = new TextArea();

    public void start(Stage primaryStage){

        Scene scene = new Scene(new ScrollPane(area), 450,300);
        primaryStage.setTitle("Test2_2Server");
        primaryStage.setScene(scene);
        primaryStage.show();

    //此处做修改，为服务器分配线程
        new Thread(() ->{
            try {
                //创建一个服务器套接字
                ServerSocket serverSocket = new ServerSocket(8000);

                area.appendText("Server started at " + new Date() + '\n');

                while (true){

                    //监听
                    Socket socket = serverSocket.accept();

                    //创建进程
                    HandleAClient task = new HandleAClient(socket);

                    //开始运行
                    new Thread(task).start();

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


    }

    public static void main(String[] args) {
        launch(args);
    }

    //服务器端的任务类
    class HandleAClient implements Runnable{
        private Socket socket;

        public HandleAClient(Socket socket1){
            this.socket = socket1;
        }

        public void run(){
            try {
                //创建输入输出流
                DataInputStream input = new DataInputStream(socket.getInputStream());
                DataOutputStream output = new DataOutputStream(socket.getOutputStream());

                while (true){
                    //获取客户端数据
                    double annualInterestRate = input.readDouble();
                    int numberOfYears = input.readInt();
                    double loanAmount = input.readDouble();

                    //计算偿还额
                    double totalPayment = loanAmount * Math.pow(1 + annualInterestRate * 0.01, numberOfYears);
                    double monthlyPayment = totalPayment / numberOfYears / 12;
                    //将数据传送至客户端
                    output.writeDouble(monthlyPayment);
                    output.writeDouble(totalPayment);
                    //输出
                    Platform.runLater(() ->{
                        area.appendText("Annual Interest Rate:" + annualInterestRate + '\n');
                        area.appendText("Number Of Year:" + numberOfYears + '\n');
                        area.appendText("Loan Amount:" + loanAmount + '\n');

                        area.appendText("Monthly Payment:" + monthlyPayment + '\n');
                        area.appendText("Total Payment:" + totalPayment + '\n');
                    });


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