还是那个题目(题目和流程见java版本),感觉光用java写一点新意也没有,恰巧刚学习了python,何不拿来一用,呵呵:
服务器端:
import SocketServer, time
class MyServer(SocketServer.BaseRequestHandler):
userInfo = {
'yangsq' : 'yangsq',
'hudeyong' : 'hudeyong',
'mudan' : 'mudan' }
def handle(self):
print 'Connected from', self.client_address
while True:
receivedData = self.request.recv(8192)
if not receivedData:
continue
elif receivedData == 'Hi, server':
self.request.sendall('hi, client')
elif receivedData.startswith('name'):
self.clientName = receivedData.split(':')[-1]
if MyServer.userInfo.has_key(self.clientName):
self.request.sendall('valid')
else:
self.request.sendall('invalid')
elif receivedData.startswith('pwd'):
self.clientPwd = receivedData.split(':')[-1]
if self.clientPwd == MyServer.userInfo[self.clientName]:
self.request.sendall('valid')
time.sleep(5)
sfile = open('PyNet.pdf', 'rb')
while True:
data = sfile.read(1024)
if not data:
break
while len(data) > 0:
intSent = self.request.send(data)
data = data[intSent:]
time.sleep(3)
self.request.sendall('EOF')
else:
self.request.sendall('invalid')
elif receivedData == 'bye':
break
self.request.close()
print 'Disconnected from', self.client_address
if __name__ == '__main__':
print 'Server is started\nwaiting for connection...\n'
srv = SocketServer.ThreadingTCPServer(('localhost', 50000), MyServer)
srv.serve_forever()
说明:
line-55到line-58的作用就相当于java中某个类里面的main函数,即一个类的入口。
python中SocketServer module里提供了好多实用的现成的类,BaseRequestHandler就是一个,它的作用是为每一个请求fork一个线程,只要继承它,就有这个能力了,哈哈,真是美事。
当然,我们继承了BaseRequestHandler,就是override它的handle方法,就像java中继承了Thread后要实现run方法一样。实际上这个handle方法的内容和我们的java版本的run函数实现的完全一样。
line-30到line-43就是处理文件下载的主要内容了。看着都挺眼熟的呵:)
这里在文件发送完后发了一个“EOF”,告诉client文件传完了。
客户端:
import socket, time
class MyClient:
def __init__(self):
print 'Prepare for connecting...'
def connect(self):
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.connect(('localhost', 50000))
sock.sendall('Hi, server')
self.response = sock.recv(8192)
print 'Server:', self.response
self.s = raw_input("Server: Do you want get the 'thinking in python' file?(y/n):")
if self.s == 'y':
while True:
self.name = raw_input('Server: input our name:')
sock.sendall('name:' + self.name.strip())
self.response = sock.recv(8192)
if self.response == 'valid':
break
else:
print 'Server: Invalid username'
while True:
self.pwd = raw_input('Server: input our password:')
sock.sendall('pwd:' + self.pwd.strip())
self.response = sock.recv(8192)
if self.response == 'valid':
print 'please wait...'
f = open('b.pdf', 'wb')
while True:
data = sock.recv(1024)
if data == 'EOF':
break
f.write(data)
f.flush()
f.close()
print 'download finished'
break
else:
print 'Server: Invalid password'
sock.sendall('bye')
sock.close()
print 'Disconnected'
if __name__ == '__main__':
client = MyClient()
client.connect()
line-34到line-41处理文件下载,client收到server的“EOF”信号后,就知道文件传完了。
最后需要说明一下python的文件,由于是内置类型,所以不想java那样有那么多的reader,writer,input,ouput啊。python中,在打开或建立一个文件时,主要是通过模式(mode)来区别的。
python的网络编程确实简单,因为它提供了各种功能的已经写好的类,直接继承就Ok了。
python还在学习中,上面的例子跑通是没问题,但写得肯定不够好,还得学习啊