這個(gè)需求來自于我最近練手的一個(gè)項(xiàng)目,在項(xiàng)目中我需要將一些自己發(fā)表的和收藏整理的網(wǎng)文集中到一個(gè)地方存放,如果全部采用手工操作工作量大而且繁瑣,因此周公決定利用C#來實(shí)現(xiàn)。在很多地方都需要驗(yàn)證用戶身份才可以進(jìn)行下一步操作,這就免不了POST請(qǐng)求來登錄,在實(shí)際過程中發(fā)現(xiàn)有些網(wǎng)站登錄是HTTPS形式的,在解決過程中遇到了一些小問題,現(xiàn)在跟大家分享。
通用輔助類
下面是我編寫的一個(gè)輔助類,在這個(gè)類中采用了HttpWebRequest中發(fā)送GET/HTTP/HTTPS請(qǐng)求,因?yàn)橛械臅r(shí)候需要獲取認(rèn)證信息(如Cookie),所以返回的是HttpWebResponse對(duì)象,有了返回的HttpWebResponse實(shí)例,可以獲取登錄過程中返回的會(huì)話信息,也可以獲取響應(yīng)流。
代碼如下:
- using System;
- using System.Collections.Generic;
- using System.Linq;
- using System.Text;
- using System.Net.Security;
- using System.Security.Cryptography.X509Certificates;
- using System.DirectoryServices.Protocols;
- using System.ServiceModel.Security;
- using System.Net;
- using System.IO;
- using System.IO.Compression;
- using System.Text.RegularExpressions;
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- namespace BaiduCang
- {
-
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- public class HttpWebResponseUtility
- {
- private static readonly string DefaultUserAgent = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; SV1; .NET CLR 1.1.4322; .NET CLR 2.0.50727)";
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- public static HttpWebResponse CreateGetHttpResponse(string url,int? timeout, string userAgent,CookieCollection cookies)
- {
- if (string.IsNullOrEmpty(url))
- {
- throw new ArgumentNullException("url");
- }
- HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
- request.Method = "GET";
- request.UserAgent = DefaultUserAgent;
- if (!string.IsNullOrEmpty(userAgent))
- {
- request.UserAgent = userAgent;
- }
- if (timeout.HasValue)
- {
- request.Timeout = timeout.Value;
- }
- if (cookies != null)
- {
- request.CookieContainer = new CookieContainer();
- request.CookieContainer.Add(cookies);
- }
- return request.GetResponse() as HttpWebResponse;
- }
-
-
-
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-
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-
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- public static HttpWebResponse CreatePostHttpResponse(string url,IDictionary<string,string> parameters,int? timeout, string userAgent,Encoding requestEncoding,CookieCollection cookies)
- {
- if (string.IsNullOrEmpty(url))
- {
- throw new ArgumentNullException("url");
- }
- if(requestEncoding==null)
- {
- throw new ArgumentNullException("requestEncoding");
- }
- HttpWebRequest request=null;
-
- if(url.StartsWith("https",StringComparison.OrdinalIgnoreCase))
- {
- ServicePointManager.ServerCertificateValidationCallback = new RemoteCertificateValidationCallback(CheckValidationResult);
- request = WebRequest.Create(url) as HttpWebRequest;
- request.ProtocolVersion=HttpVersion.Version10;
- }
- else
- {
- request = WebRequest.Create(url) as HttpWebRequest;
- }
- request.Method = "POST";
- request.ContentType = "application/x-www-form-urlencoded";
-
- if (!string.IsNullOrEmpty(userAgent))
- {
- request.UserAgent = userAgent;
- }
- else
- {
- request.UserAgent = DefaultUserAgent;
- }
-
- if (timeout.HasValue)
- {
- request.Timeout = timeout.Value;
- }
- if (cookies != null)
- {
- request.CookieContainer = new CookieContainer();
- request.CookieContainer.Add(cookies);
- }
-
- if(!(parameters==null||parameters.Count==0))
- {
- StringBuilder buffer = new StringBuilder();
- int i = 0;
- foreach (string key in parameters.Keys)
- {
- if (i > 0)
- {
- buffer.AppendFormat("&{0}={1}", key, parameters[key]);
- }
- else
- {
- buffer.AppendFormat("{0}={1}", key, parameters[key]);
- }
- i++;
- }
- byte[] data = requestEncoding.GetBytes(buffer.ToString());
- using (Stream stream = request.GetRequestStream())
- {
- stream.Write(data, 0, data.Length);
- }
- }
- return request.GetResponse() as HttpWebResponse;
- }
-
- private static bool CheckValidationResult(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors)
- {
- return true;
- }
- }
- }
從上面的代碼中可以看出POST數(shù)據(jù)到HTTP和HTTPS站點(diǎn)不同,POST數(shù)據(jù)到HTTPS站點(diǎn)的時(shí)候需要設(shè)置ServicePointManager類的ServerCertificateValidationCallback屬性,并且在POST到https://passport.baidu.com/?login時(shí)還需要將HttpWebResquest實(shí)例的ProtocolVersion屬性設(shè)置為HttpVersion.Version10(這個(gè)未驗(yàn)證是否所有的HTTPS站點(diǎn)都需要設(shè)置),否則在調(diào)用GetResponse()方法時(shí)會(huì)拋出“基礎(chǔ)連接已經(jīng)關(guān)閉: 連接被意外關(guān)閉。”的異常。
用法舉例
這個(gè)類用起來也很簡(jiǎn)單:
(1)POST數(shù)據(jù)到HTTPS站點(diǎn),用它來登錄百度:
- string loginUrl = "https://passport.baidu.com/?login";
- string userName = "userName";
- string password = "password";
- string tagUrl = "http://cang.baidu.com/"+userName+"/tags";
- Encoding encoding = Encoding.GetEncoding("gb2312");
-
- IDictionary<string, string> parameters = new Dictionary<string, string>();
- parameters.Add("tpl", "fa");
- parameters.Add("tpl_reg", "fa");
- parameters.Add("u", tagUrl);
- parameters.Add("psp_tt", "0");
- parameters.Add("username", userName);
- parameters.Add("password", password);
- parameters.Add("mem_pass", "1");
- HttpWebResponse response = HttpWebResponseUtility.CreatePostHttpResponse(loginUrl, parameters, null, null, encoding, null);
- string cookieString = response.Headers["Set-Cookie"];
(2)發(fā)送GET請(qǐng)求到HTTP站點(diǎn)
在cookieString中包含了服務(wù)器端返回的會(huì)話信息數(shù)據(jù),從中提取了之后可以設(shè)置Cookie下次登錄時(shí)帶上這個(gè)Cookie就可以以認(rèn)證用戶的信息,假設(shè)我們已經(jīng)登錄成功并且獲取了Cookie,那么發(fā)送GET請(qǐng)求的代碼如下:
- string userName = "userName";
- string tagUrl = "http://cang.baidu.com/"+userName+"/tags";
- CookieCollection cookies = new CookieCollection();
- response = HttpWebResponseUtility.CreateGetHttpResponse(tagUrl, null, null, cookies);
(3)發(fā)送POST請(qǐng)求到HTTP站點(diǎn)
以登錄51CTO為例:
- string loginUrl = "http://home.51cto.com/index.php?s=/Index/doLogin";
- string userName = "userName";
- string password = "password";
-
- IDictionary<string, string> parameters = new Dictionary<string, string>();
- parameters.Add("email", userName);
- parameters.Add("passwd", password);
-
- HttpWebResponse response = HttpWebResponseUtility.CreatePostHttpResponse(loginUrl, parameters, null, null, Encoding.UTF8, null);
在這里說句題外話,CSDN的登錄處理是由http://passport.csdn.net/ajax/accounthandler.ashx這個(gè)Handler來處理的。
總結(jié)
在本文只是講解了在C#中發(fā)送請(qǐng)求到HTTP和HTTPS的用法,分GET/POST兩種方式,為減少一些繁瑣和機(jī)械的編碼,周公將其封裝為一個(gè)類,發(fā)送數(shù)據(jù)之后返回HttpWebResponse對(duì)象實(shí)例,利用這個(gè)實(shí)例我們可以獲取服務(wù)器端返回的Cookie以便用認(rèn)證用戶的身份繼續(xù)發(fā)送請(qǐng)求,或者讀取服務(wù)器端響應(yīng)的內(nèi)容,不過在讀取響應(yīng)內(nèi)容時(shí)要注意響應(yīng)格式和編碼,本來在這個(gè)類中還有讀取HTML和WML內(nèi)容的方法(包括服務(wù)器使用壓縮方式傳輸?shù)臄?shù)據(jù)),但限于篇幅和其它方面的原因,此處省略掉了。如有機(jī)會(huì),在以后的文章中會(huì)繼續(xù)講述這方面的內(nèi)容。
周公
2011-05-08
本文出自 “周公(周金橋)的專欄” 博客,請(qǐng)務(wù)必保留此出處http://zhoufoxcn.blog.51cto.com/792419/561934