带有MIME附件的HTTP POST请求及其Headers multipart/related和xop？

Question

我正在尝试通过eBay的文件传输API上传大量数据。为了做到这一点，我需要向eBay服务器发送一个xml请求字符串，但这个xml请求中有一个<Data>部分，必须包含你要传输的数据（在这个例子中，是一个经过base64编码的zip文件，里面包含另一个xml文档）。eBay提供了一个C#的示例，教你如何构建这样的文档：https://ebay.custhelp.com/app/answers/detail/a_id/1561

我一直在尝试用python重现这个示例，使用httplib来POST我构建的字符串，方式和示例差不多（这三个UUID是唯一的）：

request = """
--MIMEBoundaryurn_uuid_{XMLUUID}
    Content-Type: application/xop+xml;charset=UTF-8;type="text/xml;charset=UTF-8";
    Content-Transfer-Encoding: binary
    Content-ID:<0.urn:uuid:{REQUUID}>
    <?xml version="1.0" encoding="utf-8"?>
    <uploadFileRequest xmlns:sct=\"http://www.ebay.com/soaframework/common/types\" xmlns="http://www.ebay.com/marketplace/services">
    <fileAttachment>
        <Size>{Size}</Size>
        <Data><xop:Include xmlns:xop="http://www.w3.org/2004/08/xop/include"
        href="cid:urn:uuid:{ATTCHMNTUUID}>"</Data>
    </fileAttachment>
    <fileFormat>{fileFormat}</fileFormat>
    <fileReferenceId>{fileReferenceId}</fileReferenceId>
    <taskReferenceId>{taskReferenceId}</taskReferenceId>
    </uploadFileRequest>
    --MIMEBoundaryurn_uuid_{XMLUUID}
    Content-Type: application/octet-stream
    Content-Transfer-Encoding: binary
    Content-ID: <urn.uuid:{ATTCHMNTUUID}>\r\n
    {Data}
    --MIMEBoundaryurn_uuid_{XMLUUID}--
    """.replace("\t", "")

request_dict = {
    'Size': size,
    'Data': payload,
    'fileFormat': 'zip',
    'fileReferenceId': '50000935383',
    'taskReferenceId': '50000847753',
    'REQUUID': reqUUID,
    'XMLUUID': xmlUUID,
    'ATTCHMNTUUID': attchmntUUID,
}


request = request.format( **request_dict )

我的请求头看起来是这样的：

headers = {
'X-EBAY-SOA-OPERATION-NAME': 'uploadFile',
'X-EBAY-SOA-SERVICE-NAME': 'FileTransferService',
'X-EBAY-SOA-SECURITY-TOKEN': #Auth Token,
'Content-type': "multipart/related; boundary=" + boundary  + ";type=\"application/xop+xml\";start=\"<0." + "urn:uuid:" + str(requuid) + ">\";start-info=\"text/xml\""
}

然后是我的POST请求：

connection = httplib.HTTPSConnection( 'storage.sandbox.ebay.com' )
connection.request( "POST", '/FileTransferService', request, headers )

当我发送没有MIME附件信息的xml请求时，文件可以正常接受。但是当我尝试像上面的代码那样，使用MIME multipart/related附件，并且用<xop>标签指明数据在附件中的位置时，POST请求就失败了，我收到了“错误302：临时移动”的响应。这让我觉得我构建的MIME multipart/related xml请求可能有问题，或者是“Content-type”头的声明有问题，或者是我使用xop的方式有问题，最有可能的是这三者的组合都有问题。

我想问的是：我该如何创建一个包含MIME multipart/related部分并且使用xop的xml请求呢？

谢谢你的帮助！

Wes

Answer 1

我找到了我请求出问题的原因。问题出在请求字符串的构造和头部信息上。我采用了一种更有条理和程序化的方法来处理这个问题，结果成功了。

下面是构建请求字符串的部分代码：

###########################################
# UUIDs
###########################################
reqUUID= uuid.uuid4()
attchmntUUID = uuid.uuid4()

##########################################
# MIME strings
##########################################
URN_UUID_REQUEST = "<0.urn:uuid:%s>"% reqUUID
URN_UUID_ATTACHMENT = "urn:uuid:%s" % attchmntUUID
MIME_BOUNDARY = "MIME_boundary"

request_dict = {
    'Size': size,
    'Data': payload,
    'fileFormat': 'gzip',
    'fileReferenceId': '50000945773',
    'taskReferenceId': '50000858033',
    'REQUUID': reqUUID,
    'ATTCHMNTUUID': attchmntUUID,
}


def build_request( request_dict):
    '''
    Build the request string with MIME Attachment
    '''

    request  = '<uploadFileRequest xmlns:sct="http://www.ebay.com/soaframework/common/types" xmlns="http://www.ebay.com/marketplace/services">\r\n'
    request += '<taskReferenceId>%s</taskReferenceId>\r\n' % request_dict['taskReferenceId']
    request += '<fileReferenceId>%s</fileReferenceId>\r\n' % request_dict['fileReferenceId']
    request += '<fileFormat>%s</fileFormat>\r\n' % request_dict['fileFormat']
    request += '<fileAttachment>\r\n'
    request += '<Size>%s</Size>\r\n'% request_dict['Size']
    request += '<Data><xop:Include xmlns:xop="http://www.w3.org/2004/08/xop/include" href="cid:%s"/></Data>\r\n'%URN_UUID_ATTACHMENT
    request += '</fileAttachment>\r\n'
    request += '</uploadFileRequest>\r\n'

    return request


def build_mime_message( request, data ):
    '''
    Build the xml string with MIME attachments and the base64 encoded data string
    '''

    request_part  = '\r\n'
    request_part += '--%s\r\n' % MIME_BOUNDARY
    request_part += 'Content-Type: application/xop+xml; charset=UTF-8; type="text/xml; charset=UTF-8"\r\n'
    request_part += 'Content-Transfer_Encoding: binary\r\n'
    request_part += 'Content-ID: %s\r\n\r\n' % URN_UUID_REQUEST
    request_part += '%s\r\n' % request


    binary_part  = '\r\n'
    binary_part += '--%s\r\n' % MIME_BOUNDARY
    binary_part += 'Content-Type: application/octet-stream\r\n'
    binary_part += 'Content-Transfer-Encoding: base64\r\n'
    binary_part += 'Content-ID: <%s>\r\n\r\n' % URN_UUID_ATTACHMENT
    binary_part += '%s\r\n' % data
    binary_part += '--%s--' % MIME_BOUNDARY

    return request_part + binary_part

request = build_request( request_dict )
request = build_mime_message( request, data )#data is base64 encoded gzip compressed xml file

而头部信息则是这样的：

content_type_string  = 'multipart/related;'
content_type_string += ' boundary=%s;' % MIME_BOUNDARY
content_type_string += ' type="application/xop+xml";'
content_type_string += ' start="%s";' % URN_UUID_REQUEST
content_type_string += ' start-info="text/xml"'

headers = {
'X-EBAY-SOA-OPERATION-NAME': 'uploadFile',
'X-EBAY-SOA-SERVICE-NAME': 'FileTransferService',
'X-EBAY-SOA-SECURITY-TOKEN': #auth token,
'Content-Length': len( request ),
'Content-Type': content_type_string
}

通过这些信息，我发现问题出在头部和请求中的换行符和制表符上。