Question

当我正在学习java socket时，我已经在两个框架中进行了一次功能但非常简单的聊天：一个客户端和一个服务器。该应用程序只在本地和工作。但是当我关闭窗口时它不会停止（虽然我将WindowListener添加到两个框架类中）：出了什么问题？

不要忘记先运行服务器，然后再运行客户端：只有在客户端连接后才会显示这两个帧。

这是SimpleSocketFrame.java（两个框架的基类）：

package com.loloof64.java_se.simple_socket;

import java.awt.GridLayout;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;

import javax.swing.JFrame;
import javax.swing.JTextArea;
import javax.swing.JTextField;

public abstract class SimpleSocketFrame extends JFrame {

    public SimpleSocketFrame() {
        setTitle(getFrameTitle());
        setLayout(new GridLayout(0, 1));

         messageToAddField = new JTextField(30);
     messageToAddField.addKeyListener(new KeyAdapter() {

            @Override
            public void keyReleased(KeyEvent e) {
                if (e.getKeyCode() == KeyEvent.VK_ENTER){
                    if ( ! messageToAddField.getText().isEmpty()) {
                        addMessage(messageToAddField.getText());
                        messageToAddField.setText("");
                    }
                }
            }

    });

        printedMessagesArea = new JTextArea(10,30);
        printedMessagesArea.setEditable(false);

        add(messageToAddField);
        add(printedMessagesArea);

    pack();
}

protected abstract void addMessage(String s);
protected abstract String getFrameTitle();

private static final long serialVersionUID = -5861605385948623162L;
protected JTextArea printedMessagesArea;
private JTextField messageToAddField;

}

这是服务器应用程序类：SimpleSocketServer.java

package com.loloof64.java_se.simple_socket;

import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.net.ServerSocket;
import java.net.Socket;

import javax.swing.JOptionPane;

public class SimpleSocketServer extends SimpleSocketFrame {

    public SimpleSocketServer(){
        super();
        setTitle("Simple Server");
        try {
            serverSocket = new ServerSocket(12345);
            relatedSocket = serverSocket.accept();

            outStream = new PrintStream(relatedSocket.getOutputStream());
            isr = new InputStreamReader(relatedSocket.getInputStream());
            inStream = new BufferedReader(isr);

            final InStreamRunnable inStreamRunnable = new InStreamRunnable();
            Thread inStreamReaderThread = new Thread(inStreamRunnable);



            addWindowListener(new WindowAdapter() {

                @Override
                public void windowClosing(WindowEvent evt) {
                    try {
                        inStream.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                    try {
                    isr.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                    outStream.close();
                try {
                    relatedSocket.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                try {
                    serverSocket.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                    inStreamRunnable.stop();
                    System.exit(0);
                }

            });

            inStreamReaderThread.start();
        } catch (IOException e) {
            JOptionPane.showMessageDialog(this, "Could not create the server !!!",
                    "Fatal error", JOptionPane.ERROR_MESSAGE);
            System.exit(1);
            e.printStackTrace();
        }
    }

    private class InStreamRunnable implements Runnable {

        @Override
        public void run() {
            while (weMustGoOn){
                String line;
                try {
                    line = inStream.readLine();
                                   printedMessagesArea.setText(printedMessagesArea.getText()+line+"\n");
                } catch (IOException e) {

                }
            }
    }

        public void stop(){
            weMustGoOn = false;
        }

        private boolean weMustGoOn = true;

    }

    @Override
    protected void addMessage(String s) {
        s = "Serveur> "+s;
        outStream.println(s);
        printedMessagesArea.setText(printedMessagesArea.getText()+"Client> "+s+"\n");
    }

    @Override
    protected String getFrameTitle() {
        return "Simple Server";
    }

    public static void main(String[] args) {
        new SimpleSocketServer().setVisible(true);
    }

    private static final long serialVersionUID = 4288994465786972478L;
    private Socket relatedSocket;
    private ServerSocket serverSocket;
    private PrintStream outStream;
    private InputStreamReader isr;
    private BufferedReader inStream;
 }

这是客户端类：SimpleSocketClient.java

package com.loloof64.java_se.simple_socket;

import java.awt.event.WindowAdapter; 
import java.awt.event.WindowEvent;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.net.InetAddress;
import java.net.Socket;

import javax.swing.JOptionPane;

public class SimpleSocketClient extends SimpleSocketFrame {

    public SimpleSocketClient(){
        try {
            socket = new Socket(InetAddress.getLocalHost(), 12345);
            outStream = new PrintStream(socket.getOutputStream());

        isr = new InputStreamReader(socket.getInputStream());
            inStream = new BufferedReader(isr); 

            final InStreamRunnable inStreamRunnable = new InStreamRunnable();
        Thread inStreamReaderThread = new Thread(inStreamRunnable);

            addWindowListener(new WindowAdapter() {

                @Override
                public void windowClosing(WindowEvent evt) {
                try {
                        inStream.close();
                } catch (IOException e2) {
                    e2.printStackTrace();
                }
                try {
                    isr.close();
                } catch (IOException e1) {
                        e1.printStackTrace();
                    }
                outStream.close();
                try {
                    socket.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                inStreamRunnable.stop();
                System.exit(0);
            }

        });
            inStreamReaderThread.start();
    } catch (IOException e) {
            JOptionPane.showMessageDialog(this, "Could not create the client !!!",
                    "Fatal error", JOptionPane.ERROR_MESSAGE);
            System.exit(1);
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {
        new SimpleSocketClient().setVisible(true);
    }

private class InStreamRunnable implements Runnable {

    @Override
    public void run() {
            while (weMustGoOn){
            String line;
            try {
                line = inStream.readLine();
                      printedMessagesArea.setText(printedMessagesArea.getText()+line+"\n");
                } catch (IOException e) {

                }
            }
        }

    public void stop(){
        weMustGoOn = false;
    }

    private boolean weMustGoOn = true;

    } 

@Override
protected void addMessage(String s) {
    s = "Client> "+s;
    outStream.println(s);
    printedMessagesArea.setText(printedMessagesArea.getText()+s+"\n");
}

@Override
    protected String getFrameTitle() {
    return "Simple Client";
}

    private static final long serialVersionUID = 5468568598525947366L;
    private Socket socket;
    private PrintStream outStream;
    private InputStreamReader isr;
    private BufferedReader inStream;


 }

Answer 1

您应该在finally和try之后添加catch块以关闭套接字，之后您可以通过系统退出方法关闭程序。

Answer 2

当您关闭正在无限期阻止的Readers时尝试关闭网络输入JFrame时，程序不会停止。 BufferedReader和InputStreamReader个对象无法关闭，因为客户端线程在等待服务器响应的readLine调用中被阻止

line = inStream.readLine();

注释或删除：

inStream.close();

和

isr.close();

关闭Socket流就足够了。

旁白：在与多线程网络应用程序的Swing组件交互时，请始终使用SwingWorker。 SwingWorkers旨在与Swing组件正确交互。

为什么这个客户端/服务器程序不会停止？

2 个答案: