JavaFX、贷款服务器

服务器：

package net;
 
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;
 
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Date;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
 
public class Exercise31_01Server extends Application {
    private ExecutorService executor = Executors.newFixedThreadPool(5);     //线程池（管理线程数量）
    private TextArea textArea = new TextArea();         //文本区域（显示信息）
    private static final int SERVER_PORT = 8000;        //端口号
 
    public static void main(String[] args) {
        launch(args);
    }
 
    @Override
    public void start(Stage primaryStage) {
        //文本区域（设置属性）
        textArea.setPrefColumnCount(40);
        textArea.setPrefRowCount(10);
        textArea.setEditable(false);
 
        Scene scene = new Scene(new ScrollPane(textArea));
        primaryStage.setScene(scene);
        primaryStage.setTitle("Exercise31_01Server");
        primaryStage.show();
 
        //启动线程
        new Thread(this::startServer).start();
    }
 
    /** 启动服务器 */
    private void startServer() {
        try {
            //创建服务器套接字
            ServerSocket server = new ServerSocket(SERVER_PORT);
            Platform.runLater(() -> textArea.appendText(this.getClass().getSimpleName() + " started at " + new Date() + "\n"));
 
            while (true) {
                //创建套接字（连接客户端）
                Socket socket = server.accept();
                Platform.runLater(() -> textArea.appendText("Connected to a client at " + new Date() + "\n"));
 
                //为连接的客户端分配一个线程
                executor.execute(new HandleClient(socket));
            }
        } catch (IOException ex) {
            ex.printStackTrace();
        } finally {
            executor.shutdown();
        }
    }
 
    /** 内部类-处理一个客户端 */
    private class HandleClient implements Runnable {
        private Socket socket;  //连接客户端的套接字
 
        public HandleClient(Socket socket) {
            this.socket = socket;
        }
 
        @Override
        public void run() {
            //输入、输出流
            DataInputStream inputFromClient = null;
            DataOutputStream outputToClient = null;
 
            try {
                inputFromClient = new DataInputStream(socket.getInputStream());
                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();
                    double monthlyRate = annualInterestRate / 1200;
                    double monthlyPayment = loanAmount * monthlyRate / (1 - 1 / Math.pow(1 + monthlyRate, numberOfYears * 12));
                    double totalPayment = monthlyPayment * 12 * numberOfYears;
 
                    //写数据到客户端
                    outputToClient.writeDouble(monthlyPayment);
                    outputToClient.writeDouble(totalPayment);
                    Platform.runLater(() ->
                        textArea.appendText("Annual Interest Rate: " + annualInterestRate + "\n" +
                                "Number of Year: " + numberOfYears + "\n" +
                                "Loan Amount: " + loanAmount + "\n" +
                                "monthlyPayment: " + monthlyPayment + "\n" +
                                "totalPayment: " + totalPayment + "\n\n"));
                }
            } catch (IOException ex) {
                textArea.appendText(ex.getMessage());
            } finally {
                try {   //关闭流
                    if (inputFromClient != null) inputFromClient.close();
                    if (outputToClient != null) outputToClient.close();
                } catch (Exception ex) {
                    ex.printStackTrace();
                }
            }
        }
    }
}

客户端：

package net;
 
import javafx.application.Application;
import javafx.application.Platform;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.*;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.GridPane;
import javafx.stage.Stage;
 
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.Socket;
 
public class Exercise31_01Client extends Application {
    private TextField annualInterestRate = new TextField();     //年利息率
    private TextField numberOfYears = new TextField();          //年数
    private TextField loanAmount = new TextField();             //贷款数量
    private Button submit = new Button("Submit");               //提交
    private TextArea message = new TextArea();                  //文本区域（显示信息）
    private static final String HOST = "localhost";             //主机/IP地址
    private static final int SERVER_PORT = 8000;                //端口号
 
    public static void main(String[] args) {
        launch(args);
    }
 
    @Override
    public void start(Stage primaryStage) {
        //总面板
        BorderPane pane = new BorderPane(new ScrollPane(message));
        pane.setTop(getTopPane());
 
        //文本区域设置属性
        message.setPrefRowCount(6);
        message.setPrefColumnCount(30);
        message.setEditable(false);
 
        //按钮设置动作事件
        submit.setOnAction(event -> handleSubmit());
 
        Scene scene = new Scene(pane);
        primaryStage.setScene(scene);
        primaryStage.setTitle("Exercise31_01Client");
        primaryStage.show();
    }
 
    /** 返回顶部面板 */
    private GridPane getTopPane() {
        //网格面板（放置文本域）
        GridPane pane = new GridPane();
        pane.setStyle("-fx-hgap: 10px; -fx-vgap: 5px;");
        pane.addRow(0, new Label("Annual Interest Rate:"), annualInterestRate);
        pane.addRow(1, new Label("Number of Years:"), numberOfYears);
        pane.addRow(2, new Label("Loan Amount:"), loanAmount);
        pane.add(submit, 2, 1);
 
        //文本域设置属性
        annualInterestRate.setAlignment(Pos.BOTTOM_RIGHT);
        numberOfYears.setAlignment(Pos.BOTTOM_RIGHT);
        loanAmount.setAlignment(Pos.BOTTOM_RIGHT);
        annualInterestRate.setPrefColumnCount(13);
        numberOfYears.setPrefColumnCount(13);
        loanAmount.setPrefColumnCount(13);
 
        return pane;
    }
 
    /** 提交信息给服务器 */
    private void handleSubmit() {
        Socket socket = null;                   //客户端套接字
        DataInputStream inputFromServer = null; //输入流
        DataOutputStream outputToServer = null; //输出流
 
        try {
            socket = new Socket(HOST, SERVER_PORT);
            inputFromServer = new DataInputStream(socket.getInputStream());
            outputToServer = new DataOutputStream(socket.getOutputStream());
 
            double annualInterestRate = Double.parseDouble(this.annualInterestRate.getText().trim());
            int numberOfYears = Integer.parseInt(this.numberOfYears.getText().trim());
            double loanAmount = Double.parseDouble(this.loanAmount.getText().trim());
 
            //发送数据到服务器
            outputToServer.writeDouble(annualInterestRate);
            outputToServer.writeInt(numberOfYears);
            outputToServer.writeDouble(loanAmount);
 
            //接受服务器数据
            double monthlyPayment = inputFromServer.readDouble();
            double totalPayment = inputFromServer.readDouble();
            Platform.runLater(() ->
                    message.appendText("Annual Interest Rate: " + annualInterestRate + "\n" +
                            "Number of Year: " + numberOfYears + "\n" +
                            "Loan Amount: " + loanAmount + "\n" +
                            "monthlyPayment: " + monthlyPayment + "\n" +
                            "totalPayment: " + totalPayment + "\n\n"));
            this.annualInterestRate.setText("");
            this.numberOfYears.setText("");
            this.loanAmount.setText("");
        } catch (IOException ex) {
            ex.printStackTrace();
        } finally {
            try {       //关闭与服务器的连接
                if (socket != null) socket.close();
                if (inputFromServer != null) inputFromServer.close();
                if (outputToServer != null) outputToServer.close();
            } catch (Exception ex) {
                ex.printStackTrace();
            }
        }
    }
}