如何向可能重定向到登录页面的页面发出POST请求 [英] How to make a POST request to a page that may redirect to a login page

问题描述

我正在Outlook VBA中使用宏通过POST将文件提交到URL:

I am using a macro in Outlook VBA to submit a file via POST to a URL:

Set http = New WinHttp.WinHttpRequest
http.Open "POST", UrlToPostTo, False    'True                                          '
http.setRequestHeader "User-Agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)"
http.setRequestHeader "Content-Type", "multipart/form-data; "
http.Send data

我的问题是，接受请求的页面(在这种情况下为文件上传页面)受身份验证保护-上面的初始请求将返回登录页面，而不是页面本身.

My problem is the page that will accept the request (a file upload page, in this case) is protected by authentication - the initial request for it above will return a login page instead of the page itself.

我试图检测是否显示登录页面，如果显示，则将用户名和密码作为表单变量发布(我希望这等同于人类在Web浏览器的页面中键入所述用户名和密码).

I have tried to detect if the login page appears and if so, post the username and password as form variables (I'm hoping this is equivalent to a human typing said username and password into a page in the web browser).

步骤如下:
*请求网址(包括带有帖子的文件).
*检查响应是否为登录页面.
*如果是这样，则在同一http会话中，将用户名和密码提交到URL.
*如果服务器现在处理原始帖子，很好，否则我可以再次发布.

So the steps are:
* request URL (include file with post).
* Check if the reponse is the login page.
* If so, then in the same http session, submit the username and password to the URL.
* If the server now processes the original post, good, otherwise I can post it again.

代码如下:

' if the login page comes back, send credentials                                     '
If (InStr(http.ResponseText, "j_password") > 0) Then

    Dim loginData As String
    loginData = "j_username=theusername&j_password=thepassword"

    http.Open "POST", UrlToPostTo, False
    http.setRequestHeader "User-Agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)"
    http.setRequestHeader "Content-Type", "multipart/form-data; "
    http.Send loginData
End If

但是，当我这样做时，http.Responsetext仍然只是登录页面(或再次登录).

But when I do this, The http.Responsetext is just the login page still (or again?).

知道我在做什么错吗?我的计划有效吗?

Any idea what I'm doing wrong? Is my plan even valid?

(这与尝试解决推荐答案

我知道此线程很古老，并且我意识到OP无疑是很久以前开发的.我只是度过了三个晚上的大部分时间，因为同样的问题而感到沮丧，当我停止研究更多内容时，这个话题就不断出现，所以我想我会为下一个出现的人做出贡献.

I know this thread is ancient and I realize the OP most definitely moved on long ago. I just spent the better part of 3 evenings being humbled by this exact same problem, and this thread kept coming up when I would stop to research more so I thought I would contribute for the next guy who comes along.

诀窍是:

• 使用禁用重定向Option 属性，以阻止 没有你继续前进. (请参阅下面的评论)
• 在状态属性，以及 从那里处理.

• Disable redirects using using the Option property, to stop it from moving on without you. (see comments below)
• Capture the redirect on the output of the Status property, and handle from there.

我确定还有其他方法，但这对我来说似乎很优雅，我发现了很多其他使用方法.

I'm sure there's other ways, but this seemed pretty elegant to me, and I found lots of other ways to use it.

要使用OPs代码示例，可以按计划发出请求，但有一个例外:EnableRedirects var，它必须在打开连接后出现(在任何地方都看不到，只是无法让它坚持下去)封闭的连接.)

To use the OPs code example, you could make your request as planned with one exception: The EnableRedirects var, which must come after opening the connection (didn't read that anywhere, just couldn't get it to stick to a closed connection).

下一个家伙"祝你好运！

Good luck "next guy"!

    Dim http As WinHttp.WinHttpRequest
    Dim UrlToPostTo As String, UrlRedirectedTo As String

    'Your initial request (assuming lots here)
    Set http = New WinHttp.WinHttpRequest
    http.Open "POST", UrlToPostTo, False
    'Stop it from redirecting automatically, so you can capture it
    http.Option(WinHttpRequestOption_EnableRedirects) = False 'You can also use the collection index instead of the pretty name
    http.setRequestHeader "User-Agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)"
    http.setRequestHeader "Content-Type", "multipart/form-data; "
    http.Send

    'Now if you have an active session, you should get your desired content
    'If it redirected you, you'll have a different status, header etc...    

    If http.status = "302" Then
        Dim loginData As String
        'Now lets find out where we're being pointed and POST there
        'This may not be the same url you see in your address bar 
        UrlRedirectedTo = http.GetResponseHeader("Location")
        'Also, you may have to do this again to arrive back at the intended resource    
        loginData = "j_username=theusername&j_password=thepassword"
        http.Open "POST", UrlRedirectedTo, False
        http.setRequestHeader "User-Agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)"
        http.setRequestHeader "Content-Type", "multipart/form-data; "
        http.Send loginData
    End If

我发现在MSDN迷宫中有用的一些信息.

Some info I found useful in the MSDN maze.

WinHttpRequest选项(MSDN)

WinHttpRequest对象(MSDN)

Cookie处理WinHttp(MSDN )

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