使用 Swing GUI 的简单客户端-服务器程序 [英] Simple Client-Server program using Swing GUI
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问题描述
我正在制作一个简单的无线程 客户端-服务器程序，其中 GUI 在两个服务器上都有一个按钮em> 和 客户端.当 client 按下按钮时，它会将按钮上的文本更改为 "C" 并发送到 server "C" 字符串，因此服务器端的按钮将文本更改为C".服务器的工作方式与客户端类似，但发送S"而不是C".它们轮流工作:当轮到客户时，服务器的按钮被锁定，他不能改变他的按钮.客户端总是先启动.
I'm making a simple, no thread Client-Server program where GUI has one button on both server and client side. When client presses button it changes text on a button to "C" and sends to server "C" string, so the button on the server side changes text to "C". Server works similarly to client but sends "S" instead of "C". They work in turns: when it's the client's turn, server's button is locked and he cannot change his button. Client always starts first.
当客户端按下按钮时它工作正常，但是当服务器按下按钮时它在服务器上将按钮更改为S" 端，但不是 客户端 端.我知道我做错了什么.
When client presses button it works fine, but when server presses button it changes button to "S" on the server side but not on client's side. I know what I'm doing wrong.
服务器代码:
public class Serv implements ActionListener
{
private JButton button;
private boolean myTurn;
private ServerSocket sock;
private Socket s;
private BufferedReader input;
private PrintStream output;
public Serv() throws UnknownHostException, IOException
{
button = new JButton();
myTurn = false;
sock = new ServerSocket(9001);
s = null;
button = new JButton();
}
public void createGUI()
{
JFrame frame = new JFrame("TicTacToe - Server");
JPanel mainPanel = new JPanel();
mainPanel.setPreferredSize(new Dimension(100, 100));
button = new JButton("");
button.setPreferredSize(new Dimension(100, 100));
button.setFont(new Font(button.getFont().getName(), button.getFont().getStyle(), 70));
button.setActionCommand("1");
button.addActionListener(this);
mainPanel.add(button);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(mainPanel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public void startMyGame() throws IOException
{
createGUI();
s = sock.accept();
input = new BufferedReader(new InputStreamReader(s.getInputStream()));
output = new PrintStream(s.getOutputStream(), true);
while(true)
{
if(myTurn == false)
{
myTurn = true;
String out = input.readLine();
button.setText(out);
}
}
}
public static void main(String args[])
{
Serv tc = null;
try
{
tc = new Serv();
tc.startMyGame();
}
catch(Exception ex)
{
ex.printStackTrace();
}
finally
{
try
{
tc.close();
}
catch(Exception ex)
{
ex.printStackTrace();
}
}
}
private void close() throws IOException
{
this.sock.close();
this.input.close();
this.output.close();
}
@Override
public void actionPerformed(ActionEvent e)
{
if(myTurn == true)
{
if(e.getActionCommand().equals("1"))
{
JButton b = (JButton) e.getSource();
b.setText("S");
output.println("S");
myTurn = false;
}
}
}
}
客户代码:
public class Cli implements ActionListener
{
private JButton button;
private boolean myTurn;
private Socket sock;
private BufferedReader input;
private PrintStream output;
public Cli() throws UnknownHostException, IOException
{
button = new JButton();
myTurn = true;
sock = new Socket("127.0.0.1", 9001);
input = new BufferedReader(new InputStreamReader(sock.getInputStream()));
output = new PrintStream(sock.getOutputStream(), true);
}
public void createGUI()
{
JFrame frame = new JFrame("TicTacToe - Client");
JPanel mainPanel = new JPanel();
mainPanel.setPreferredSize(new Dimension(100, 100));
button = new JButton("");
button.setPreferredSize(new Dimension(100, 100));
button.setFont(new Font(button.getFont().getName(), button.getFont().getStyle(), 70));
button.setActionCommand("1");
button.addActionListener(this);
mainPanel.add(button);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(mainPanel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public void startMyGame() throws IOException
{
createGUI();
while(true)
{
if(myTurn == false)
{
myTurn = true;
String out = input.readLine();
button.setText(out);
}
}
}
private void close() throws IOException
{
this.sock.close();
this.input.close();
this.output.close();
}
public static void main(String args[])
{
Cli tc = null;
try
{
tc = new Cli();
tc.startMyGame();
}
catch(Exception ex)
{
ex.printStackTrace();
}
finally
{
try
{
tc.close();
}
catch(Exception ex)
{
ex.printStackTrace();
}
}
}
@Override
public void actionPerformed(ActionEvent e)
{
if(myTurn == true)
{
if(e.getActionCommand().equals("1"))
{
JButton b = (JButton) e.getSource();
if(!b.getText().equals("X") || !b.getText().equals("O"))
{
b.setText("C");
output.println("C");
myTurn = false;
}
}
}
}
}
我删除了导入，所以代码会更短.
I have deleted imports so the codes would be shorter.
推荐答案
您的代码的当前问题:
- 您正在创建 Swing GUI 并关闭 Swing 事件调度线程或 EDT 运行它.GUI 应该在事件线程上启动，以便保证所有 Swing 代码都在单个线程上运行.
- 您有一个长时间运行的 while 循环，它正在执行 Swing 突变调用，更新 JButton 的状态.如果此代码在 Swing 事件线程上运行，它将阻塞/冻结 GUI.该块应该在不是 EDT 的后台线程中显式调用，并且所有 Swing 调用都应该按照 课程:Swing 中的并发 教程.
- 您在不同的线程中使用非易失性布尔值，冒着变量在应该更改时未被更改的风险
- 您似乎立即关闭了您的信息流，阻碍了关注点之间的充分沟通.
- You're creating a Swing GUI and running it off of the Swing event dispatch thread or EDT. GUI's should be started on the event thread so that all Swing code is guaranteed to run on a single thread.
- You've got a long-running while loop, and it is making Swing mutational calls, updating the state of a JButton. If this code were running on the Swing event thread, it would block/freeze the GUI. This block should be explicitly called in a background thread that is not the EDT, and all Swing calls should be queued onto the event thread as per the Lesson: Concurrency in Swing tutorial.
- You're using a non-volatile boolean in different threads, risking the variable not being changed when it should be changed
- You appear to be closing your streams immediately, preventing adequate communication between concerns.
正在编写一个更简洁的示例......
Working on a cleaner example.......
例如:
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.io.IOException;
import java.io.PrintStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Scanner;
import javax.swing.*;
public class SimpleServerClient {
private static final int PORT = 9001;
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> {
try {
SimpleServer server = new SimpleServer(PORT, "Server", false);
SimpleClient client = new SimpleClient(PORT, "Client", true);
server.createGui();
client.createGui();
} catch (IOException e) {
e.printStackTrace();
}
});
}
}
interface SimpleGui {
void sendLine(String nextLine);
}
// background thread handles listening to the Scanner
// which scans a Socket's InputStream
class MyWorker extends SwingWorker<Void, Void> {
public static final String LINE = "line";
private Scanner inputScanner;
private SimpleGui gui;
private String line = "";
public MyWorker(Scanner inputScanner, SimpleGui gui) {
this.inputScanner = inputScanner;
this.gui = gui;
}
@Override
protected Void doInBackground() throws Exception {
while (inputScanner.hasNext()) {
// get line from Scanner
// use the setter method in case we want to use a PropertyChangeListener later
setLine(inputScanner.nextLine());
// send line to the GUI
gui.sendLine(getLine());
}
return null;
}
public String getLine() {
return line;
}
// again rigged up to allow use of PropertyChangeListeners
public void setLine(String line) {
this.line = line;
firePropertyChange(LINE, null, line);
}
}
// code that both the client and server GUI classes share
abstract class DefaultGui implements SimpleGui {
// this guy ***must**** be volitile!
private volatile boolean myTurn;
protected Scanner inputScanner;
protected PrintStream out;
protected JButton button = new JButton("Blank");
protected Socket socket;
protected String name;
protected int port;
public DefaultGui(int port, String name, boolean myTurn) {
this.port = port;
this.name = name;
this.myTurn = myTurn;
}
@Override
public void sendLine(String nextLine) {
button.setText(nextLine);
myTurn = true;
}
public void createGui() {
button.addActionListener(e -> actionPerformed(e));
JPanel panel = new JPanel();
panel.setPreferredSize(new Dimension(300, 300));
panel.add(button);
JFrame frame = new JFrame(getName());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(panel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
protected void actionPerformed(ActionEvent e) {
if (!myTurn) {
return;
}
out.println(getName());
button.setText(getName());
myTurn = false;
}
public String getName() {
return name;
}
}
class SimpleServer extends DefaultGui {
private ServerSocket serverSocket;
public SimpleServer(int port, String name, boolean myTurn) throws IOException {
super(port, name, myTurn);
serverSocket = new ServerSocket(port);
new Thread(() -> {
try {
// accept() blocks the current thread, so must be called on a background thread
socket = serverSocket.accept();
inputScanner = new Scanner(socket.getInputStream());
out = new PrintStream(socket.getOutputStream(), true);
new MyWorker(inputScanner, this).execute();
} catch (IOException e) {
e.printStackTrace();
}
}).start();
}
}
class SimpleClient extends DefaultGui {
public SimpleClient(int port, String name, boolean myTurn) throws IOException {
super(port, name, myTurn);
socket = new Socket("localhost", port);
inputScanner = new Scanner(socket.getInputStream());
out = new PrintStream(socket.getOutputStream());
new MyWorker(inputScanner, this).execute();
}
}
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