单聊与群聊
一对一聊天（TCP）
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.ArrayList;
import java.util.List;
public class TCPServer {
private List clients = new ArrayList<>();
public static void main(String[] args) {
new TCPServer().startServer();
}
public void startServer() {
try {
ServerSocket serverSocket = new ServerSocket(12345);
System.out.println("Server listening on port 12345");
while (true) {
Socket clientSocket = serverSocket.accept();
System.out.println("New client connected: " + clientSocket);
ClientHandler clientHandler = new ClientHandler(clientSocket);
clients.add(clientHandler);
Thread thread = new Thread(clientHandler);
thread.start();
}
} catch (IOException e) {
e.printStackTrace();
}
}
private class ClientHandler implements Runnable {
private Socket clientSocket;
private InputStream inputStream;
private OutputStream outputStream;
public ClientHandler(Socket clientSocket) {
this.clientSocket = clientSocket;
try {
this.inputStream = clientSocket.getInputStream();
this.outputStream = clientSocket.getOutputStream();
} catch (IOException e) {
e.printStackTrace();
}
}
@Override
public void run() {
try {
while (true) {
byte[] buffer = new byte[1024];
int bytesRead = inputStream.read(buffer);
if (bytesRead == -1) {
break;
}
String receivedMessage = new String(buffer, 0, bytesRead);
System.out.println("Received from " + clientSocket + ": " + receivedMessage);
broadcastMessage(receivedMessage);
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
clientSocket.close();
clients.remove(this);
System.out.println("Connection closed: " + clientSocket);
} catch (IOException e) {
e.printStackTrace();
}
}
}
public void sendMessage(String message) {
try {
outputStream.write(message.getBytes());
} catch (IOException e) {
e.printStackTrace();
}
}
}
private void broadcastMessage(String message) {
for (ClientHandler client : clients) {
client.sendMessage(message);
}
}
} 客户端
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;
public class TCPClient extends JFrame {
private JTextArea chatArea;
private JTextField messageField;
private JButton sendButton;
private Socket socket;
private InputStream inputStream;
private OutputStream outputStream;
public static void main(String[] args) {
new TCPClient().startClient();
}
public void startClient() {
try {
socket = new Socket("localhost", 12345);
inputStream = socket.getInputStream();
outputStream = socket.getOutputStream();
} catch (IOException e) {
e.printStackTrace();
}
SwingUtilities.invokeLater(() -> {
initialize();
startMessageReceiver();
setVisible(true);
});
}
private void initialize() {
setTitle("TCP Chat Client");
setSize(400, 300);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
chatArea = new JTextArea();
chatArea.setEditable(false);
JScrollPane scrollPane = new JScrollPane(chatArea);
messageField = new JTextField();
sendButton = new JButton("Send");
sendButton.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
sendMessage();
}
});
setLayout(new BorderLayout());
add(scrollPane, BorderLayout.CENTER);
add(messageField, BorderLayout.SOUTH);
add(sendButton, BorderLayout.EAST);
}
private void startMessageReceiver() {
Thread receiverThread = new Thread(() -> {
try {
while (true) {
byte[] buffer = new byte[1024];
int bytesRead = inputStream.read(buffer);
if (bytesRead == -1) {
break;
}
String receivedMessage = new String(buffer, 0, bytesRead);
appendToChatArea(receivedMessage);
}
} catch (IOException e) {
e.printStackTrace();
}
});
receiverThread.start();
}
private void sendMessage() {
try {
String message = messageField.getText();
outputStream.write(message.getBytes());
messageField.setText("");
} catch (IOException e) {
e.printStackTrace();
}
}
private void appendToChatArea(String message) {
SwingUtilities.invokeLater(() -> {
chatArea.append(message + "\n");
});
}
}群聊（UDP）
服务器端
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.util.ArrayList;
import java.util.List;
public class UDPServer {
private List clients = new ArrayList<>();
public static void main(String[] args) {
new UDPServer().startServer();
}
public void startServer() {
try {
DatagramSocket serverSocket = new DatagramSocket(12346);
System.out.println("Server listening on port 12346");
while (true) {
byte[] receiveData = new byte[1024];
DatagramPacket receivePacket = new DatagramPacket(receiveData, receiveData.length);
serverSocket.receive(receivePacket);
String message = new String(receivePacket.getData(), 0, receivePacket.getLength());
System.out.println("Received from " + receivePacket.getAddress() + ": " + message);
broadcastMessage(message, receivePacket.getAddress());
}
} catch (Exception e) {
e.printStackTrace();
}
}
private void broadcastMessage(String message, InetAddress senderAddress) {
for (ClientHandler client : clients) {
if (!client.getAddress().equals(senderAddress)) {
client.sendMessage(message);
}
}
}
private class ClientHandler {
private InetAddress address;
private int port;
public ClientHandler(InetAddress address, int port) {
this.address = address;
this.port = port;
}
public InetAddress getAddress() {
return address;
}
public int getPort() {
return port;
}
public void sendMessage(String message) {
try {
DatagramSocket socket = new DatagramSocket();
byte[] sendData = message.getBytes();
DatagramPacket sendPacket = new DatagramPacket(sendData, sendData.length, address, port);
socket.send(sendPacket);
socket.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
} 客户端
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
public class UDPClient extends JFrame {
private JTextArea chatArea;
private JTextField messageField;
private JButton sendButton;
private DatagramSocket socket;
private InetAddress serverAddress;
private int serverPort = 12346; // Use a different port for UDP
public static void main(String[] args) {
new UDPClient().startClient();
}
public void startClient() {
try {
socket = new DatagramSocket();
serverAddress = InetAddress.getByName("localhost");
} catch (Exception e) {
e.printStackTrace();
}
SwingUtilities.invokeLater(() -> {
initialize();
startMessageReceiver();
setVisible(true);
});
}
private void initialize() {
setTitle("UDP Chat Client");
setSize(400, 300);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
chatArea = new JTextArea();
chatArea.setEditable(false);
JScrollPane scrollPane = new JScrollPane(chatArea);
messageField = new JTextField();
sendButton = new JButton("Send");
sendButton.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
sendMessage();
}
});
setLayout(new BorderLayout());
add(scrollPane, BorderLayout.CENTER);
add(messageField, BorderLayout.SOUTH);
add(sendButton, BorderLayout.EAST);
}
private void startMessageReceiver() {
Thread receiverThread = new Thread(() -> {
try {
while (true) {
byte[] receiveData = new byte[1024];
DatagramPacket receivePacket = new DatagramPacket(receiveData, receiveData.length);
socket.receive(receivePacket);
String receivedMessage = new String(receivePacket.getData(), 0, receivePacket.getLength());
appendToChatArea(receivedMessage);
}
} catch (Exception e) {
e.printStackTrace();
}
});
receiverThread.start();
}
private void sendMessage() {
try {
String message = messageField.getText();
byte[] sendData = message.getBytes();
DatagramPacket sendPacket = new DatagramPacket(sendData, sendData.length, serverAddress, serverPort);
socket.send(sendPacket);
messageField.setText("");
} catch (Exception e) {
e.printStackTrace();
}
}
private void appendToChatArea(String message) {
SwingUtilities.invokeLater(() -> {
chatArea.append(message + "\n");
});
}
}