几乎在学习、使用任何一种编程语言的时候,关于socket的练习从来都不会少,尤其是会写一些局域网的通信的东西。所以书上的这个项目刚好可以练习一下socket编程。
这个练习的整体思路首先有一个聊天的服务器,这个服务器的功能主要是提供客户端socket的连接、存储每个客户端的连接session,处理每个连接发送的消息、解析客户端发送的数据。就这些,至于客户端方面不需要写代码,用系统的telnet工具即可。
我觉得有了上面的分析,剩下的这个程序就没有什么说的了,当然,除了那两个把socket封装的类之外。
自己使用python中的socket类尝试这个编写了一个简单的通信程序,不过不知为什么,通信中总是出现意外。这段简单的代码如下:
server.py
import socket mysocket = socket.socket(socket.AF_INET,socket.SOCK_STREAM) mysocket.bind(('',8888)) mysocket.listen(5) while True: connection,addr = mysocket.accept() revStr = connection.recv(1024) connection.send('Server:' + revStr) connection.close()
clinet.py
import socket import time clientsocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM) clientsocket.connect(('',8888)) while True: time.sleep(2) clientsocket.send('hello the5fire') print clientsocket.recv(1024) clientsocket.close()
这个程序出错的原因没有去细揪,因为python中提供了两个封装好的类来完成socket通信过程:asynchat中的async_chat和asyncore中的dispatcher以及asyncore本身。前面的类是用来处理客户端同服务器的每一次会话,后面的类主要是用来提供socket连接服务。并且将每一个socket连接都托管给前者(async_chat)来处理。
来看代码:
from asyncore import dispatcher from asynchat import async_chat import socket, asyncore PORT = 5005 NAME = 'TestChat' class EndSession(Exception):pass class CommandHandler: def unknown(self, session, cmd): session.push('Unknown command: %s\r\n' % cmd) def handle(self, session, line): if not line.strip(): return parts = line.split(' ',1) cmd = parts[0] try: line = parts[1].strip() except IndexError: line = '' meth = getattr(self, 'do_'+cmd, None) try: meth(session, line) except TypeError: self.unknown(session,cmd) class Room(CommandHandler): def __init__(self, server): self.server = server self.sessions = [] def add(self, session): self.sessions.append(session) def remove(self, session): self.sessions.remove(session) def broadcast(self, line): for session in self.sessions: session.push(line) def do_logout(self, session, line): raise EndSession class LoginRoom(Room): def add(self,session): Room.add(self,session) self.broadcast('Welcome to %s\r\n' % self.server.name) def unknown(self, session, cmd): session.push('Please log in \nUse "login"\r\n') def do_login(self, session, line): name = line.strip() if not name: session.push('Please enter a name\r\n') elif name in self.server.users: session.push('The name "%s" is taken.\r\n' % name) sessoin.push('Please try again.\r\n') else: session.name = name session.enter(self.server.main_room) class ChatRoom(Room): def add(self, session): self.broadcast(session.name + ' has entered the room.\r\n') self.server.users[session.name] = session Room.add(self, session) def remove(self, session): Room.remove(self, session) self.broadcast(session.name + ' has left the room.\r\n') def do_say(self, session, line): self.broadcast(session.name + ': ' + line + '\r\n') def do_look(self, session, line): session.push('The following are in this room:\r\n') for other in self.sessions: session.push(other.name + '\r\n') def do_who(self, session, line): session.push('The following are logged in:\r\n') for name in self.server.users: session.push(name + '\r\n') class LogoutRoom(Room): def add(self, session): try: del self.server.users[session.name] except KeyError: pass class ChatSession(async_chat): def __init__(self, server, sock): async_chat.__init__(self,sock) self.server = server self.set_terminator('\r\n') self.data = [] self.name = None self.enter(LoginRoom(server)) def enter(self, room): try: cur = self.room except AttributeError: pass else: cur.remove(self) self.room = room room.add(self) def collect_incoming_data(self, data): self.data.append(data) def found_terminator(self): line = ''.join(self.data) self.data = [] try: self.room.handle(self, line) except EndSession: self.handle_close() def handle_close(self): async_chat.handle_close(self) self.enter(LogoutRoom(self.server)) class ChatServer(dispatcher): def __init__(self, port, name): dispatcher.__init__(self) self.create_socket(socket.AF_INET, socket.SOCK_STREAM) self.bind(('',port)) self.listen(5) self.name = name self.users = {} self.main_room = ChatRoom(self) def handle_accept(self): conn, addr = self.accept() ChatSession(self,conn) if __name__ == '__main__': s = ChatServer(PORT, NAME) try: asyncore.loop() except KeyboardInterrupt: print
整个程序分为我一开始说的三个部分:
提供客户端的socket连接:ChatServer类。
存储每个客户端的连接session,处理每个连接发送的消息:ChatSession类,这个类的作用很简单,接受数据,判断是否有终结符,如果有调用found_terminator这个方法。
解析客户端发送的数据:就是剩下的room相关的类,这些类分别用来处理客户端发送的字符串和命令,都是继承自CommandHandler。
最终截图:
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持。