通过Python中的套接字（仅限）发送图像，无法打开图像 [英] Sending image over sockets (ONLY) in Python, image can not be open

问题描述

我想使用Python中的ONLY套接字将图像从客户端上传到服务器。我设计了一个非常简单的协议流程，我想这样做：

I want to upload the image from client to server using ONLY sockets in Python. I designed a very simple protocol flow of how I would like to do this:

CLIENT                                       SERVER
               SIZE 512 (send image size)
         ---------------------------------->
                      GOT SIZE   
         <---------------------------------- 
                 send image itself
         ---------------------------------->
                      GOT IMAGE
         <----------------------------------
                      BYE BYE 
         ---------------------------------->
                server closes socket

这是我的客户代码：

#!/usr/bin/env python

import random
import socket, select
from time import gmtime, strftime
from random import randint

image = "tux.png"

HOST = '127.0.0.1'
PORT = 6666

sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server_address = (HOST, PORT)
sock.connect(server_address)

try:

    # open image
    myfile = open(image, 'rb')
    bytes = myfile.read()
    size = len(bytes)

    # send image size to server
    sock.sendall("SIZE %s" % size)
    answer = sock.recv(4096)

    print 'answer = %s' % answer

    # send image to server
    if answer == 'GOT SIZE':
        sock.sendall(bytes)

        # check what server send
        answer = sock.recv(4096)
        print 'answer = %s' % answer

        if answer == 'GOT IMAGE' :
            sock.sendall("BYE BYE ")
            print 'Image successfully send to server'

    myfile.close()

finally:
    sock.close()

我的服务器，从客户端接收图像：

And my server, which receives images from clients:

#!/usr/bin/env python

import random
import socket, select
from time import gmtime, strftime
from random import randint

imgcounter = 1
basename = "image%s.png"

HOST = '127.0.0.1'
PORT = 6666

connected_clients_sockets = []

server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
server_socket.bind((HOST, PORT))
server_socket.listen(10)

connected_clients_sockets.append(server_socket)

while True:

    read_sockets, write_sockets, error_sockets = select.select(connected_clients_sockets, [], [])

    for sock in read_sockets:

        if sock == server_socket:

            sockfd, client_address = server_socket.accept()
            connected_clients_sockets.append(sockfd)

        else:
            try:

                data = sock.recv(4096)
                txt = str(data)

                if txt.startswith('SIZE'):
                    tmp = txt.split()
                    size = int(tmp[1])

                    print 'got size'

                    sock.send("GOT SIZE")

                elif txt.startswith('BYE'):
                    sock.shutdown()

                elif data:

                    myfile = open(basename % imgcounter, 'wb')

                    data = sock.recv(40960000)
                    if not data:
                        myfile.close()
                        break
                    myfile.write(data)
                    myfile.close()

                    sock.send("GOT IMAGE")
                    sock.shutdown()
            except:
                sock.close()
                connected_clients_sockets.remove(sock)
                continue
        imgcounter += 1
server_socket.close()

示例图片：

客户端打印出消息，表明它已成功将图像发送到服务器：

The client prints out messages, that suggest, that it send the image to server successfully:

answer = GOT SIZE
answer = GOT IMAGE
Image successfully send to server

图像是在服务器端创建的，但我不能操作恩。是的，我尝试了不同的图像。没有成功。我无法在服务器端打开它们，即使它们在那里可用。

The image is created at server's side, but I can not open it. And yes, I tried different images. With no success. I can't open them at server's side, even though they are available there.

感谢@BorrajaX，我设法让它发挥作用！谢谢！ ：）

Thanks to @BorrajaX, I managed to make it work! Thanks! :)

#!/usr/bin/env python

import random
import socket, select
from time import gmtime, strftime
from random import randint

imgcounter = 1
basename = "image%s.png"

HOST = '127.0.0.1'
PORT = 6666

connected_clients_sockets = []

server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
server_socket.bind((HOST, PORT))
server_socket.listen(10)

connected_clients_sockets.append(server_socket)

while True:

    read_sockets, write_sockets, error_sockets = select.select(connected_clients_sockets, [], [])

    for sock in read_sockets:

        if sock == server_socket:

            sockfd, client_address = server_socket.accept()
            connected_clients_sockets.append(sockfd)

        else:
            try:

                data = sock.recv(4096)
                txt = str(data)

                if data:

                    if data.startswith('SIZE'):
                        tmp = txt.split()
                        size = int(tmp[1])

                        print 'got size'

                        sock.sendall("GOT SIZE")

                    elif data.startswith('BYE'):
                        sock.shutdown()

                    else :

                        myfile = open(basename % imgcounter, 'wb')
                        myfile.write(data)

                        data = sock.recv(40960000)
                        if not data:
                            myfile.close()
                            break
                        myfile.write(data)
                        myfile.close()

                        sock.sendall("GOT IMAGE")
                        sock.shutdown()
            except:
                sock.close()
                connected_clients_sockets.remove(sock)
                continue
        imgcounter += 1
server_socket.close()

推荐答案

好的问题是，在接收到实际图像的情况下，您正在读取套接字两次并忽略第一次读取中的数据并仅写入第二次读取中接收的数据。所以你的图像文件不完整。请参阅下面的修复程序，您可以从中进行优化，将其作为起点。它就是这样的。

Okay your problem is, in the case of actual image received, you are reading the socket two times and ignoring the data in the first read and just writing the data received in the second read. So your image file is incomplete. See my fix below , you can optimize from this taking it as starting point. It works as such.

#!/usr/bin/env python

import random
import socket, select
from time import gmtime, strftime
from random import randint

imgcounter = 1
basename = "image%s.png"

HOST = '127.0.0.1'
PORT = 6666

connected_clients_sockets = []

server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
server_socket.bind((HOST, PORT))
server_socket.listen(10)

connected_clients_sockets.append(server_socket)
buffer_size = 4096

while True:

    read_sockets, write_sockets, error_sockets = select.select(connected_clients_sockets, [], [])



    for sock in read_sockets:

        if sock == server_socket:

            sockfd, client_address = server_socket.accept()
            connected_clients_sockets.append(sockfd)

        else:
            try:
                print ' Buffer size is %s' % buffer_size
                data = sock.recv(buffer_size)
                txt = str(data)

                if txt.startswith('SIZE'):
                    tmp = txt.split()
                    size = int(tmp[1])

                    print 'got size'
                    print 'size is %s' % size

                    sock.send("GOT SIZE")
                    # Now set the buffer size for the image 
                    buffer_size = 40960000

                elif txt.startswith('BYE'):
                    sock.shutdown()

                elif data:

                    myfile = open(basename % imgcounter, 'wb')

                    # data = sock.recv(buffer_size)
                    if not data:
                        myfile.close()
                        break
                    myfile.write(data)
                    myfile.close()

                    sock.send("GOT IMAGE")
                    buffer_size = 4096
                    sock.shutdown()
            except:
                sock.close()
                connected_clients_sockets.remove(sock)
                continue
        imgcounter += 1
server_socket.close() 

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