HttpWebRequest和HttpWebResponse

原文:http://blog.csdn.net/haitaofeiyang/article/details/18362225

申公前几日和一个客户做系统对接，以前和客户对接一般采用webservice或者json 解析的方式，直接调用标准解析就可以。没想到客户用“请求响应模式”，直接访问人家的接口地址取数据，无奈打造一个通用的访问类吧

参考MSDN的解释：

HttpWebRequest类：提供WebRequest类的Http特定的实现。

HttpWebRequest 类对 WebRequest 中定义的属性和方法提供支持，也对使用户能够直接与使用 HTTP 的服务器交互的附加属性和方法提供支持。

不要使用构造函数创建HttpWebRequest实例，请使用System.Net.WebRequest.Create(URI uriString)来创建实例，如果URI是Http://或Https://， 
返回的是HttpWebRequest对象。(建立请求特定URI的对象) 
当向资源发送数据时，GetRequestStream方法返回用于发送数据的Stream对象。(获取请求数据的流对象) 
GetResponse方法向RequestUri属性指定的资源发出同步请求并返回包含该响应的HttpWebResponse。(获取来自internet的响应)

好了，直接上代码：

using System.Net;
using System.IO;
using System.Security.Cryptography.X509Certificates;
using System.Net.Security;
using System.Windows.Forms;

/*
 * 作者：申公
 * 日期：
 * 说明：此类提供http，POST和GET访问远程接口
 * */
namespace ZJS.EDI.Business.HttpUtility
{
    /// <summary>
    /// 有关HTTP请求的辅助类
    /// </summary>
    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)";//浏览器
        private static Encoding requestEncoding = System.Text.Encoding.UTF8;//字符集

        /// <summary>
        /// 创建GET方式的HTTP请求
        /// </summary>
        /// <param name="url">请求的URL</param>
        /// <param name="timeout">请求的超时时间</param>
        /// <param name="userAgent">请求的客户端浏览器信息，可以为空</param>
        /// <param name="cookies">随同HTTP请求发送的Cookie信息，如果不需要身份验证可以为空</param>
        /// <returns></returns>
        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;
        }

        /// <summary>
        /// 创建POST方式的HTTP请求
        /// </summary>
        /// <param name="url">请求的URL</param>
        /// <param name="parameters">随同请求POST的参数名称及参数值字典</param>
        /// <param name="cookies">随同HTTP请求发送的Cookie信息，如果不需要身份验证可以为空</param>
        /// <returns></returns>
        public static HttpWebResponse CreatePostHttpResponse(string url, string parameters, CookieCollection cookies)
        {
            if (string.IsNullOrEmpty(url))
            {
                throw new ArgumentNullException("url");
            }

            HttpWebRequest request = null;
            Stream stream = null;//用于传参数的流

            try
            {
                //如果是发送HTTPS请求
                if (url.StartsWith("https", StringComparison.OrdinalIgnoreCase))
                {
                    ServicePointManager.ServerCertificateValidationCallback = new RemoteCertificateValidationCallback(CheckValidationResult);
                    request = WebRequest.Create(url) as HttpWebRequest;
                    //创建证书文件
                    System.Security.Cryptography.X509Certificates.X509Certificate objx509 = new System.Security.Cryptography.X509Certificates.X509Certificate(Application.StartupPath + @"\\licensefile\zjs.cer");
                    //添加到请求里
                    request.ClientCertificates.Add(objx509);
                    request.ProtocolVersion = HttpVersion.Version10;
                }
                else
                {
                    request = WebRequest.Create(url) as HttpWebRequest;
                }

                request.Method = "POST";//传输方式
                request.ContentType = "application/x-www-form-urlencoded";//协议
                request.UserAgent = DefaultUserAgent;//请求的客户端浏览器信息,默认IE
                request.Timeout = 6000;//超时时间，写死6秒

                //随同HTTP请求发送的Cookie信息，如果不需要身份验证可以为空
                if (cookies != null)
                {
                    request.CookieContainer = new CookieContainer();
                    request.CookieContainer.Add(cookies);
                }

                //如果需求POST传数据，转换成utf-8编码
                byte[] data = requestEncoding.GetBytes(parameters);
                request.ContentLength = data.Length;

                stream = request.GetRequestStream();
                stream.Write(data, 0, data.Length);

                stream.Close();
            }
            catch (Exception ee)
            {
                //写日志
                //LogHelper.
            }
            finally
            {
                if (stream != null)
                {
                    stream.Close();
                }
            }

            return request.GetResponse() as HttpWebResponse;
        }

        //验证服务器证书回调自动验证
        private static bool CheckValidationResult(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors)
        {
            return true; //总是接受
        }

        /// <summary>
        /// 获取数据
        /// </summary>
        /// <param name="HttpWebResponse">响应对象</param>
        /// <returns></returns>
        public static string OpenReadWithHttps(HttpWebResponse HttpWebResponse)
        {
            Stream responseStream = null;
            StreamReader sReader = null;
            String value = null;

            try
            {
                // 获取响应流
                responseStream = HttpWebResponse.GetResponseStream();
                // 对接响应流(以"utf-8"字符集)
                sReader = new StreamReader(responseStream, Encoding.GetEncoding("utf-8"));
                // 开始读取数据
                value = sReader.ReadToEnd();
            }
            catch (Exception)
            {
                //日志异常
            }
            finally
            {
                //强制关闭
                if (sReader != null)
                {
                    sReader.Close();
                }
                if (responseStream != null)
                {
                    responseStream.Close();
                }
                if (HttpWebResponse != null)
                {
                    HttpWebResponse.Close();
                }
            }

            return value;
        }

        /// <summary>
        /// 入口方法：获取传回来的XML文件
        /// </summary>
        /// <param name="url">请求的URL</param>
        /// <param name="parameters">随同请求POST的参数名称及参数值字典</param>
        /// <param name="cookies">随同HTTP请求发送的Cookie信息，如果不需要身份验证可以为空</param>
        /// <returns></returns>
        public static string GetResultXML(string url, string parameters, CookieCollection cookies)
        {
            return OpenReadWithHttps(CreatePostHttpResponse(url, parameters, cookies));
        }

    }
}

调用实例：

/// 调用主程序
/// </summary>
public class Program
{

    static string strUrlPre = ; // 测试环境Url
    static string strKey = ;// 签名密钥
    static string strMethod = ;// 方法编号

    static void Main(string[] args)
    {
        //MessageBox.Show("请注意，马上将进行保存操作!");           

        StringBuilder sbRequestData =;//请求参数

        // 发送请求
        StringBuilder sbUrl = new StringBuilder(); // 请求URL内容
        sbUrl.Append(strUrlPre);
        sbUrl.Append("?");
        sbUrl.Append("sign=" + strKeyMD5);
        sbUrl.Append("&" + sbSystemArgs.ToString());

        String strUrl = sbUrl.ToString();
        //解析xml文件
        string resultXML = HttpWebResponseUtility.GetResultXML(sbUrl.ToString(), sbRequestData.ToString(), null);

    }
}