网络编程实操题

以下是一个基于Socket的简单的聊天室实操题。

要求：

1. 实现一个多人在线聊天室，可以支持多个客户端连接到服务器并进行聊天。
2. 客户端可以输入用户名，服务器会记录下来并将其显示在聊天室中。
3. 客户端可以输入消息并发送给其他客户端，服务器会将其转发给所有连接到服务器的客户端。
4. 实现基本的异常处理，例如客户端异常断开连接、服务器异常关闭等情况。

提示：

1. 可以使用Python的socket模块来实现网络通信。
2. 服务器可以使用单线程或多线程的方式实现，可以考虑使用select模块来实现多路复用。
3. 客户端可以使用命令行或简单的图形界面来实现。

代码示例：

服务器端代码：

import socket

HOST = '127.0.0.1' # Server IP address
PORT = 8888 # Server port
BUFSIZ = 1024 # Buffer size
ADDR = (HOST, PORT)

server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server_socket.bind(ADDR)
server_socket.listen(5)

print('Server started at {}:{}'.format(HOST, PORT))

# List of client sockets
client_sockets = []

while True:
    # Wait for a new client connection
    client_socket, client_addr = server_socket.accept()
    print('Client {}:{} connected'.format(client_addr[0], client_addr[1]))

    # Add the new client socket to the list
    client_sockets.append(client_socket)

    # Send a welcome message to the new client
    client_socket.send('Welcome to the chat room! Please enter your username:'.encode('utf-8'))

    # Receive the username of the new client
    username = client_socket.recv(BUFSIZ).decode('utf-8')
    print('Client {}:{} username is {}'.format(client_addr[0], client_addr[1], username))

    # Send a welcome message to all clients
    for sock in client_sockets:
        if sock != client_socket:
            sock.send('{} joined the chat room!'.format(username).encode('utf-8'))

    # Start a new thread to handle the client connection
    # You can also use select() to handle multiple connections in the same thread
    while True:
        try:
            data = client_socket.recv(BUFSIZ)
            if not data:
                break
            # Broadcast the message to all clients
            for sock in client_sockets:
                if sock != client_socket:
                    sock.send('[{}] {}: {}'.format(username, client_addr[0], data.decode('utf-8')).encode('utf-8'))
        except Exception as e:
            print('Client {}:{} error: {}'.format(client_addr[0], client_addr[1], e))
            break

    # Remove the client socket from the list
    client_sockets.remove(client_socket)

    # Send a leave message to all clients
    for sock in client_sockets:
        sock.send('{} left the chat room!'.format(username).encode('utf-8'))

    # Close the client socket
    client_socket.close()

# Close the server socket
server_socket.close()

客户端代码：

import socket
import threading

HOST = '127.0.0.1' # Server IP address
PORT = 8888 # Server port
BUFSIZ = 1024 # Buffer size

client_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
client_socket.connect((HOST, PORT))

# Receive messages from the server
def receive():
    while True:
        try:
            data = client_socket.recv(BUFSIZ)
            print(data.decode('utf-8'))
        except Exception as e:
            print('Error: {}'.format(e))
            break

# Start a new thread to receive messages from the server
receive_thread = threading.Thread(target=receive)
receive_thread.start()

# Send messages to the server
username = input('Please enter your username:')
client_socket.send(username.encode('utf-8'))

while True:
    try:
        message = input('')
        if message == 'quit':
            break
        client_socket.send(message.encode('utf-8'))
    except Exception as e:
        print('Error: {}'.format(e))
        break

# Close the client socket
client_socket.close()

运行方式：

1. 在终端中运行服务器端代码：`python server.py`
2. 在多个终端中分别运行客户端代码：`python client.py`
3. 在客户端中输入用户名并发送消息即可在聊天室中进行聊天，输入`quit`退出程序。