tidhttp 获取程序不适用于某些网址

发布于 2024-08-24 10:55:12 字数 916 浏览 8 评论 0原文

我在 delphi Tidhttp 组件中遇到一个问题，其中 GET 过程无法获取特定的 url，但在其他 url 上它正在工作。示例：此代码返回一个空的response.datastring。仅对于此 error_url，Response.datastring 为空，但对于其他 url，response.datastring 具有值。我需要获取该 error_url 的内容来解决这个问题。

procedure TForm1.Button1Click(Sender: TObject);
var
  Response : TStringStream;
  error_url: string;
begin
  error_url := 'http://www.chefscatalog.com/international/home.aspx'; //error url
  Response := TStringStream.Create;
  try
    IdHTTP1.Get(error_url, Response);
    Memo1.Text := Response.DataString;
  finally
    FreeAndNil(Response);
  end;
end;

顺便说一下，idHTTP1 重定向属性在这里设置为 true，因此重定向不是问题。

这是我遇到的异常： 1.http/1.1 302 找到 2. EDecompressionError 并显示消息“ZLib Error (-3)”

您可以在此链接中下载该项目的源代码（indytest.zip） http://www.yourfilelink.com/get.php?fid=534933

请帮助我。提前致谢：）

原文

I am encountering a problem in delphi Tidhttp component wherein the GET procedure can't fetch a specific url but on other urls it is working. Example: this code returns an empty response.datastring. Response.datastring is empty only with this error_url but with other urls the response.datastring has a value. I need to fetch the content of that error_url to fix this problem.

procedure TForm1.Button1Click(Sender: TObject);
var
  Response : TStringStream;
  error_url: string;
begin
  error_url := 'http://www.chefscatalog.com/international/home.aspx'; //error url
  Response := TStringStream.Create;
  try
    IdHTTP1.Get(error_url, Response);
    Memo1.Text := Response.DataString;
  finally
    FreeAndNil(Response);
  end;
end;

By the way idHTTP1 redirect property is set here to true so redirection is not the problem.

This is the exception I encountered:
1. http/1.1 302 Found
2. EDecompressionError with message 'ZLib Error (-3)'

You can download the source code (which is indytest.zip) of this project in this link http://www.yourfilelink.com/get.php?fid=534933

Please help me guys. Thanks in advance :)

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小姐丶请自重 2024-08-31 10:55:12

原因是您尝试访问的网站正在寻找 cookie，如果未设置它，它会尝试设置它，然后执行 302 重定向回其自身。

因为您没有连接 cookie 管理器，所以您最终会陷入 302 重定向循环，因为网站会不断检查 cookie、设置然后重定向。

处理 cookie，只需一个 302 就可以正常工作。

但是，由于某种原因，Indy 似乎忽略了该站点发送的 cookie。如果我点击 http://www.google.com 我会编写一些测试代码，我得到的

New cookie: PREF
New cookie: NID
Redirecting (1) to: http://www.google.co.nz/
New cookie: PREF
New cookie: NID

是标题谷歌发送

Set-Cookie: PREF=ID=3c7e441914b902ae:TM=1268686477:LM=1268686477:S=Z-Gwqx52jK0V1rYR; expires=Wed, 14-Mar-2012 20:54:37 GMT; path=/; domain=.google.com
Set-Cookie: NID=32=vsOZvkr4AOZ7320d_OBPf2zR2jau4E6pupbOe_ZaaX4DNjahTzSV-mSA55naTk-5cXQcn7SNEp7uSxbE_cFrL9ZftGApTGZMPGKzcz3_NZE_2MYpWG5PGbwWFw9t2d_R; expires=Tue, 14-Sep-2010 20:54:37 GMT; path=/; domain=.google.com; HttpOnly

但是对于其他站点，我在调试输出中

Redirecting (1) to: http://www.chefscatalog.com/error.aspx?impsid=0
Redirecting (2) to: http://www.chefscatalog.com/error.aspx?impsid=0

一直得到这个，最多尝试 15 次。
如果我们查看站点发回的标头，

Set-Cookie: ASP.NET_SessionId=4o0bpi45evee0d45qos1uy55; path=/; HttpOnly
Set-Cookie: ChefsSite=CartID=00000000-0000-0000-0000-000000000000&cst=f4t8YpBpAAkNiRUd9BEf2luKAA%3d%3d&act=c0f2VBCSbv30F4kasnvWS5OfJQ%3d%3d&CookiesEnabled=False; expires=Wed, 14-Apr-2010 20:54:22 GMT; path=/

我会注意到该站点缺少 Set-Cookie 末尾的域，这很奇怪，但我不认为 RFC 必须这样做。如果我们查看 idCookieManager 的 AddCookie/2 方法，它需要该参数上的主机，因此它可能无法在任何不提供域的 Set-Cookie 上工作。

我已经在另外几个网站上对此进行了测试，如果 Set-Cookie 包含domain=.google.com，则一切正常；

值得注意的是，在 idHttp.OnRedirect 上，如果您查看

idHttp.Response.RawHeaders.Text

不起作用的网站的，您不会看到 Set-Cookies，但在起作用的网站上，您确实会看到Set-Cookies...

但是，如果我将 idhttp useragent 设置为

    Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2.1) Gecko/20100122 firefox/3.6.1

（来自另一个答案），

那么它似乎可以很好地拾取 cookie 很

    New cookie: ASP.NET_SessionId
    New cookie: ChefsSite
    Redirecting (1) to: http://www.chefscatalog.com/international/home.aspx
    New cookie: ChefsSite

奇怪。

The reason is the website you are trying to hit is looking for a cookie and if it's not getting set it tries to set it, and then does a 302 redirect back to it's self.

Because you haven't hooked up a cookie manager you are ending up in a 302 redirect loop as the site keeps checking for cookie, setting and then redirecting.

Handle cookies and it will work just fine with only a single 302.

However it seems that for some reason Indy is ignoring the cookies that are being sent by this site. I whipped up some test code if I hit http://www.google.com I get

New cookie: PREF
New cookie: NID
Redirecting (1) to: http://www.google.co.nz/
New cookie: PREF
New cookie: NID

this is the headers that google send

Set-Cookie: PREF=ID=3c7e441914b902ae:TM=1268686477:LM=1268686477:S=Z-Gwqx52jK0V1rYR; expires=Wed, 14-Mar-2012 20:54:37 GMT; path=/; domain=.google.com
Set-Cookie: NID=32=vsOZvkr4AOZ7320d_OBPf2zR2jau4E6pupbOe_ZaaX4DNjahTzSV-mSA55naTk-5cXQcn7SNEp7uSxbE_cFrL9ZftGApTGZMPGKzcz3_NZE_2MYpWG5PGbwWFw9t2d_R; expires=Tue, 14-Sep-2010 20:54:37 GMT; path=/; domain=.google.com; HttpOnly

However for that other site, I get this in my debug output

Redirecting (1) to: http://www.chefscatalog.com/error.aspx?impsid=0
Redirecting (2) to: http://www.chefscatalog.com/error.aspx?impsid=0

all the way up to 15 attempts..
if we look at what headers the site sends back

Set-Cookie: ASP.NET_SessionId=4o0bpi45evee0d45qos1uy55; path=/; HttpOnly
Set-Cookie: ChefsSite=CartID=00000000-0000-0000-0000-000000000000&cst=f4t8YpBpAAkNiRUd9BEf2luKAA%3d%3d&act=c0f2VBCSbv30F4kasnvWS5OfJQ%3d%3d&CookiesEnabled=False; expires=Wed, 14-Apr-2010 20:54:22 GMT; path=/

I note there the site is missing the domain off the end of the Set-Cookie, which is weird but I don't think it's a must from the RFC. if we look at the AddCookie/2 methods of idCookieManager its wanting a host on that param so maybe it wont work on any Set-Cookies that don't give the domain.

I have tested this on a couple more sites and all work fine IF the Set-Cookie includes domain=.google.com;

It's also interesting to note that on the idHttp.OnRedirect if you look at

idHttp.Response.RawHeaders.Text

for the site that doesn't work you don't see the Set-Cookies but on the sites that do work you do see the Set-Cookies...

However, if I set idhttp useragent to

    Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2.1) Gecko/20100122 firefox/3.6.1

(from another answer)

then it seems to pickup the cookies just fine

    New cookie: ASP.NET_SessionId
    New cookie: ChefsSite
    Redirecting (1) to: http://www.chefscatalog.com/international/home.aspx
    New cookie: ChefsSite

Weird.

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