网络编程的专利权应该属于Unix,各个平台(如windows、Linux等)、各门语言(C、C++、Python、Java等)所实现的符合自身特性的语法都大同小异。在我看来,懂得了Unix的socket网络编程,其他的形式的网络编程方法也就知道了。这句话说得还不太严谨。准确的应该说成懂得了socket编程的原理,网络编程也就知道了,不同之处就在于每个平台,每个语言都有自己专享的语法,我们直接灵活套用就行了。
下面是用python实现的最基本的网络编程的例子,即依托于客户端-服务器的架构,实现客户端与服务器之间的单向“数据流通”。我们分别用两个方法来实现,一个方法是最原始的socket编程,另一个方法是利用python的面向对象对第一种方法进行封装实现,目的是减少实现透明性,便于快速开发。
要求:客户端输入数据,发送到服务端,服务器端生成(时间戳+数据)的封装数据回应客户端。由于socket编程包括两种:面向连接的和无连接的,这两种分别对应TCP数据流和UDP数据报文。所以,我们两种方法都进行实现。
一、Python socket编程
面向连接的TCP socket编程:
1 # -*- coding: utf-8 -*-
2
3 from socket import *
4 from time import ctime
5
6 # Address and Port
7 HOST = ''
8 PORT = 21567
9 ADDR = (HOST, PORT)
10
11 # BuffSize
12 BUFSIZ = 1024
13
14 # build socket
15 tcpSerSock = socket(AF_INET, SOCK_STREAM)
16 # bind socket
17 tcpSerSock.bind(ADDR)
18 # listen 5 client
19 tcpSerSock.listen(5)
20
21 try:
22 while True:
23 print 'waiting for connection...'
24 # build client socket
25 tcpCliSock, addr = tcpSerSock.accept()
26 print '...connect from:', addr
27
28 # accept data and process
29 while True:
30 data = tcpCliSock.recv(BUFSIZ)
31 if not data:
32 break
33 tcpCliSock.send('[%s] %s' % (ctime(), data))
34
35 # close client socket
36 tcpCliSock.close()
37 except EOFError, KeyboardInterrupt:
38 tcpSerSock.close()
1 # -*- coding:utf-8 -*-
2
3 from socket import *
4
5 # Address and Port
6 HOST = '127.0.0.1'
7 PORT = 21567
8 ADDR = (HOST, PORT)
9
10 # BufferSize
11 BUFSIZ = 1024
12
13 #build socket
14 tcpCliSocket = socket(AF_INET, SOCK_STREAM)
15 tcpCliSocket.connect(ADDR)
16
17 while True:
18 data = raw_input('> ')
19 if not data:
20 break
21 # send data
22 tcpCliSocket.send(data)
23 # recv data
24 data = tcpCliSocket.recv(BUFSIZ)
25 if not data:
26 break
27 # show data
28 print data
29 tcpCliSocket.close()
无连接的UDP socket编程
1 # -*- coding: utf-8 -*-
2
3 from socket import *
4 from time import ctime
5
6 # Address and Port
7 HOST = ''
8 PORT = 8000
9 ADDR = (HOST, PORT)
10
11 # BufferSize
12 BUFFSIZE = 1024
13 # build socket
14 udpSerSock = socket(AF_INET, SOCK_DGRAM)
15 # bind socket
16 udpSerSock.bind(ADDR)
17
18 try:
19 while True:
20 print 'waiting the message...'
21 data, addr = udpSerSock.recvfrom(BUFFSIZE)
22 print 'received the message: '+data+' from: ', addr
23 udpSerSock.sendto('[%s] %s' % (ctime(), data), addr)
24 except EOFError, KeyboardInterrupt:
25 udpSerSock.close()
1 # -*- coding: utf-8 -*-
2
3 from socket import *
4
5 # Address and Port
6 HOST = 'localhost'
7 PORT = 8000
8 ADDR = (HOST, PORT)
9
10 # BufferSize
11 BUFSIZ = 1024
12
13 # build socket
14 udpCliSock = socket(AF_INET, SOCK_DGRAM)
15
16 while True:
17 data = raw_input('> ')
18 udpCliSock.sendto(data, ADDR)
19 data = udpCliSock.recvfrom(BUFSIZ)
20 if not data:
21 break
22 print data
23 udpCliSock.close()
二、基于封装类SocketServer的网络编程
1 # -*- coding: utf-8 -*-
2
3 from SocketServer import TCPServer as TCP, StreamRequestHandler as SRH
4 from time import ctime
5
6 # Address and Port
7 HOST = ''
8 PORT = 21567
9 ADDR = (HOST, PORT)
10
11 # BuffSize
12 BUFSIZ = 1024
13
14 # build RequestHandler
15 class MyRequestHandler(SRH):
16 def handle(self):
17 print '...connected from: ', self.client_address
18 self.wfile.write('[%s] %s' % (ctime(), self.rfile.readline()))
19
20 # build TCPServer
21 TCPServ = TCP(ADDR, MyRequestHandler)
22 print 'waiting for connection...'
23 # loop to process
24 TCPServ.serve_forever()
1 # -*- coding:utf-8 -*-
2
3 from socket import *
4
5 # Address and Port
6 HOST = '127.0.0.1'
7 PORT = 21567
8 ADDR = (HOST, PORT)
9
10 # BufferSize
11 BUFSIZ = 1024
12
13 while True:
14 # note: SocketServer 的请求处理器的默认行为是接受连接,
15 # 得到请求,然后就关闭连接,所以需要多次连接
16 tcpCliSock = socket(AF_INET, SOCK_STREAM)
17 tcpCliSock.connect(ADDR)
18
19 # process data
20 data = raw_input('> ')
21 if not data:
22 break
23 tcpCliSock.send('%s\r\n' % data)
24
25 data = tcpCliSock.recv(BUFSIZ)
26 if not data:
27 break
28 print data.strip()
29 tcpCliSock.close()