delphi - 为什么当我连接到 Whatismyip.com 时会收到 "403 Forbidden"？

Question

使用以下代码，我得到异常类 EIdHTTPProtocolException 和消息“HTTP/1.1 403 Forbidden”。进程 svchostip.exe (11172)

function GetInternetIP:string;
var
  IdHTTPMainUrl : TIdHTTP;
begin
  try
    IdHTTPMainUrl := TIdHTTP.Create(nil);
    IdHTTPMainUrl.Request.Host := 'http://www.whatismyip.com/automation/n09230945.asp';
    Result := idHTTPMainUrl.Get('http://automation.whatismyip.com/n09230945.asp');
  except
    IdHTTPMainUrl.Free;
  end;
end;

Answer 1

您需要设置您的用户代理，这记录在 WhatIsMyIP faq 中:

•Please set your program's user agent to Mozilla/5.0 (Windows NT 6.1; WOW64; rv:12.0) Gecko/20100101 Firefox/12.0 , this will keep your program from being blocked by CloudFlare

此外，释放 TIdHTTP 实例应该是无条件的，只有在引发异常时才释放它。使用异常处理来处理异常。

function GetInternetIP:string;
var
  IdHTTPMainUrl : TIdHTTP;
begin
  IdHTTPMainUrl := TIdHTTP.Create(nil);
  try
    IdHTTPMainUrl.Request.UserAgent :=
      'Mozilla/5.0 (Windows NT 6.1; WOW64; rv:12.0) Gecko/20100101 Firefox/12.0';
    Result := idHTTPMainUrl.Get('http://automation.whatismyip.com/n09230945.asp');
  finally
    IdHTTPMainUrl.Free;
  end;
end;