通过Python中的套接字(仅限)发送图像,无法打开图像

Question

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:

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

这是我的客户端代码:

#!/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:

#!/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()

对于示例图像:

客户端打印出消息,表明它成功将图像发送到服务器:

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

图像是在服务器端创建的,但我无法打开它.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.

感谢@BorrajaX,我设法让它发挥作用!谢谢!:)

#!/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()

Answer 1

好的，问题是，在收到实际图像的情况下，您正在读取套接字两次，并且忽略第一次读取时的数据，而只是写入第二次读取中的数据。因此，您的图片文件不完整。请参阅下面的修复程序，您可以以此为起点进行优化。它是这样工作的。

#!/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()