什么是SocketServer？

SocketServer的最主要的作用是实现并发处理,也就是可以多个用户同时上传和下载文件。

socketserver模块简化了编写网络服务器的任务。

socketserver一共有这么几种类型

class socketserver.TCPServer(server_address, RequestHandlerClass, bind_and_activate=True)

这使用Internet TCP协议，该协议提供客户端和服务器之间的连续数据流。

class socketserver.UDPServer(server_address, RequestHandlerClass, bind_and_activate=True)

它使用数据报文，这是离散的信息包，在传输过程中可能会无序到达或丢失。参数与TCPServer相同。

class socketserver.UnixStreamServer(server_address, RequestHandlerClass, bind_and_activate=True)class socketserver.UnixDatagramServer(server_address, RequestHandlerClass,bind_and_activate=True)

这些不常用的类与TCP和UDP类相似，但是使用Unix域套接字;它们在非unix平台上不可用。参数与TCPServer相同。

在继承关系图中有五个类，其中四个代表四种类型的同步服务器:

+------------+

| BaseServer |

+------------+

|

v

+-----------+ +------------------+

| TCPServer |------->| UnixStreamServer |

+-----------+ +------------------+

|

v

+-----------+ +--------------------+

| UDPServer |------->| UnixDatagramServer |

+-----------+ +--------------------+

创建一个socketserver 至少分以下几步:

1、首先，必须通过子类化BaseRequestHandlerclass并重写其handle()方法创建一个请求处理程序类;此方法将处理传入的请求。

2、其次，必须实例化一个服务器类，将服务器的地址和请求处理程序类传递给它。

3、然后调用服务器对象的handle_request() orserve_forever()方法来处理一个或多个请求。

4、最后，调用server_close()来关闭套接字

## server.py ##

importsocketserverclass MyTCPHandler(socketserver.BaseRequestHandler): #定义MyTCPHandler这个类

"""The request handler class for our server.

It is instantiated once per connection to the server, and must

override the handle() method to implement communication to the

client."""

def handle(self): #handel默认自父亲里面是空的 作用是什么？就是跟客户端所有操作，都是在handle里完成的，每个请求过来，都会走这里

whileTrue:try:

self.data= self.request.recv(1024).strip()print("{} wrote:".format(self.client_address[0])) #打印客户端的IP地址

print(self.data)#if not self.data: # 客户端断开连接

#print(self.client_address,"断开连接！")

#break

self.request.send(self.data.upper())exceptConnectionResetError as error:print("客户端已经断开连接！",error)break

if __name__ == "__main__":

HOST, PORT= "HW-20180425SPSL", 6969server=socketserver.TCPServer((HOST, PORT), MyTCPHandler)

server.serve_forever()

## client.py ##

importsocket

client= socket.socket() #生命socket类型 同时 生成socket连接# 对相

client.connect(('HW-20180425SPSL',6969)) #连接6969端口

whileTrue:

msg= input(">>:").strip()

client.send(msg.encode("utf-8"))

data= client.recv(1024) # print(data.decode())

client.close()

显示结果：

client.py

server.py

当客户端进行断开操作，那么服务端会出现什么情况呢？

SocketServer多并发操作

下面的程序是实现多用户在线Ftp程序

## client.py ##

importsocketimportosimportjsonclassFtpClient(object):def __init__(self):

self.client=socket.socket()defhelp(self):

msg= '''ls

pwd

cd ../..

get filename

put filename'''

print(msg)defconnect(self,ip,port):

self.client.connect((ip, port))definteractive(self):#self.authenticate()

whileTrue:

cmd= input(">>").strip()if len(cmd) ==0:continuecmd_str=cmd.split()[0]if hasattr(self,"cmd_%s" %cmd_str):

func= getattr(self,"cmd_%s" %cmd_str)

func(cmd)else:

self.help()def cmd_put(self,*args):

cmd_split=args[0].split()if len(cmd_split) > 1:

filename= cmd_split[1]ifos.path.isfile(filename):

filesize=os.stat(filename).st_size

msg_dic={"action": "put","filename":filename,"size": filesize,"overridden":True

}

self.client.send( json.dumps(msg_dic).encode("utf-8") )print("send",json.dumps(msg_dic).encode("utf-8") )#防止粘包，等服务器确认

server_response = self.client.recv(1024)

f= open(filename,"rb")for line inf:

self.client.send(line)else:print("file upload success...")

f.close()else:print(filename,"is not exist")defcmd_get(self):passftp=FtpClient()

ftp.connect('HW-20180425SPSL', 6969)

ftp.interactive()

## server.py ##

importsocketserverimportjsonimportosclassMyTCPHandler(socketserver.BaseRequestHandler):def put(self,*args):'''接收客户端文件'''cmd_dic=args[0]

filename= cmd_dic["filename"]

filesize= cmd_dic["size"]ifos.path.isfile(filename):

f= open(filename + ".new","wb")else:

f= open(filename , "wb")

self.request.send(b"200 ok")

received_size=0while received_size

data= self.request.recv(1024)

f.write(data)

received_size+=len(data)else:print("file [%s] has uploaded..." %filename)defhandle(self):whileTrue:try:

self.data= self.request.recv(1024).strip()print("{} wrote:".format(self.client_address[0]))print(self.data)

cmd_dic=json.loads(self.data.decode())

action= cmd_dic["action"]ifhasattr(self,action):

func=getattr(self,action)

func(cmd_dic)exceptConnectionResetError as e:print("err",e)break

if __name__ == "__main__":

HOST, PORT= "HW-20180425SPSL", 6969

#Create the server, binding to localhost on port 9999

server =socketserver.ThreadingTCPServer((HOST, PORT), MyTCPHandler)

server.serve_forever()

结果显示：

client:

client(1):

server: