### 使用 Python 实现网络聊天软件 可以基于 `socket` 和多线程技术构建一个简单的网络聊天应用程序。以下是完整的实现方案： #### 客户端代码 客户端负责连接到服务器并发送/接收消息。 ```python import socket import threading def receive_messages(client_socket): """ 接收来自服务器的消息 """ while True: try: message = client_socket.recv(1024).decode() if not message: break print(message) except ConnectionResetError: print("服务器已断开连接...") break def send_message(client_socket): """ 发送消息给服务器 """ while True: message = input("") if message.strip().lower() == 'exit': client_socket.close() break client_socket.sendall(message.encode()) if __name__ == "__main__": HOST = "127.0.0.1" PORT = 50007 with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s: s.connect((HOST, PORT)) # 启动两个线程分别处理接收和发送消息 receiver_thread = threading.Thread(target=receive_messages, args=(s,)) sender_thread = threading.Thread(target=send_message, args=(s,)) receiver_thread.start() sender_thread.start() # 等待线程结束 receiver_thread.join() sender_thread.join() ``` [^3] --- ### 使用 Python 实现文件服务器程序 可以通过 `socket` 创建一个支持上传和下载功能的简单文件服务器。 #### 服务器端代码 服务器监听客户端请求，并提供文件上传或下载的服务。 ```python import os import socket from threading import Thread BUFFER_SIZE = 4096 def handle_client_connection(conn, addr): """ 处理单个客户端连接 """ conn.send(b"Welcome to the File Server! Type 'upload' or 'download'.\n") command = conn.recv(BUFFER_SIZE).decode().strip() if command == "upload": filename = conn.recv(BUFFER_SIZE).decode().strip() file_size_data = conn.recv(BUFFER_SIZE).decode().strip() file_size = int(file_size_data) with open(f"server_files/{filename}", "wb") as f: bytes_received = 0 while bytes_received < file_size: data = conn.recv(min(BUFFER_SIZE, file_size - bytes_received)) if not data: break f.write(data) bytes_received += len(data) conn.send(b"File uploaded successfully.\n") elif command == "download": filename = conn.recv(BUFFER_SIZE).decode().strip() filepath = f"server_files/{filename}" if os.path.exists(filepath): conn.send(str(os.path.getsize(filepath)).encode()) with open(filepath, "rb") as f: while chunk := f.read(BUFFER_SIZE): conn.send(chunk) else: conn.send(b"-1\n") # 表示文件不存在 conn.close() def start_server(host="127.0.0.1", port=50008): server = socket.socket(socket.AF_INET, socket.SOCK_STREAM) server.bind((host, port)) server.listen(5) print(f"Server listening on {host}:{port}") while True: conn, addr = server.accept() print(f"[NEW CONNECTION] {addr} connected.") thread = Thread(target=handle_client_connection, args=(conn, addr)) thread.start() if __name__ == "__main__": start_server() ``` [^1] #### 客户端代码 客户端可以选择上传或下载文件至服务器。 ```python import socket BUFFER_SIZE = 4096 def upload_file(s, filename): filesize = os.path.getsize(filename) s.send("upload".encode()) s.send(os.path.basename(filename).encode()) s.send(str(filesize).encode()) with open(filename, "rb") as f: while read_bytes := f.read(BUFFER_SIZE): s.send(read_bytes) def download_file(s, filename): s.send("download".encode()) s.send(filename.encode()) file_size = int(s.recv(BUFFER_SIZE).decode()) if file_size == -1: print("文件未找到!") return total_recv = 0 with open(f"downloads/{os.path.basename(filename)}", "wb") as f: while total_recv < file_size: data = s.recv(BUFFER_SIZE) if not data: break f.write(data) total_recv += len(data) print("文件下载完成!") if __name__ == "__main__": host = "127.0.0.1" port = 50008 s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.connect((host, port)) action = input("请选择操作 (upload/download): ").strip() if action == "upload": filename = input("输入要上传的文件路径: ") upload_file(s, filename) elif action == "download": filename = input("输入要下载的文件名: ") download_file(s, filename) s.close() ``` --- ### 总结 上述代码展示了如何利用 Python 的 `socket` 库创建一个基础的网络聊天应用以及文件传输服务。这些例子涵盖了 TCP 协议的基础通信机制，同时也引入了多线程的概念以提高并发性能。