.Net整合Json实现REST服务客户端的方法详解

using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;

namespace psi.Common
{
 public class HttpClientUtil
 {
 // REST @GET 方法，根据泛型自动转换成实体，支持List<T> 
 public static T doGetMethodToObj<T>(string url)
 {
 HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
 request.Method = "get";
 request.ContentType = "application/json;charset=UTF-8";
 HttpWebResponse response = null;
 try
 {
 response = (HttpWebResponse)request.GetResponse();
 }
 catch (WebException e)
 {
 response = (HttpWebResponse)e.Response;
 return default(T);
 }
 string json = getResponseString(response);
 return JsonConvert.DeserializeObject<T>(json);
 }

 // 将 HttpWebResponse 返回结果转换成 string 
 private static string getResponseString(HttpWebResponse response)
 {
 string json = null;
 using (StreamReader reader = new StreamReader(response.GetResponseStream(), System.Text.Encoding.GetEncoding("UTF-8")))
 {
 json = reader.ReadToEnd();
 }
 return json;
 }

 // 获取异常信息 
 private static string getRestErrorMessage(HttpWebResponse errorResponse)
 {
 string errorhtml = getResponseString(errorResponse);
 string errorkey = "UnhandledException:";
 errorhtml = errorhtml.Substring(errorhtml.IndexOf(errorkey) + errorkey.Length);
 errorhtml = errorhtml.Substring(0, errorhtml.IndexOf("\n"));
 return errorhtml;
 }

 // REST @POST 方法 
 public static T doPostMethodToObj<T>(string url, string jsonBody)
 {
 HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
 request.Method = "post";
 request.ContentType = "application/json;charset=UTF-8";
 var stream = request.GetRequestStream();
 using (var writer = new StreamWriter(stream))
 {
 writer.Write(jsonBody);
 writer.Flush();
 }
 HttpWebResponse response = (HttpWebResponse)request.GetResponse();
 string json = getResponseString(response);
 return JsonConvert.DeserializeObject<T>(json);
 }

 // REST @PUT 方法 
 public static string doPutMethod(string url)
 {
 HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
 request.Method = "put";
 request.ContentType = "application/json;charset=UTF-8";
 HttpWebResponse response = (HttpWebResponse)request.GetResponse();
 using (StreamReader reader = new StreamReader(response.GetResponseStream(), System.Text.Encoding.GetEncoding("UTF-8")))
 {
 return reader.ReadToEnd();
 }
 }

 // REST @PUT 方法，带发送内容主体 
 public static T doPutMethodToObj<T>(string url, string jsonBody)
 {
 HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
 request.Method = "put";
 request.ContentType = "application/json;charset=UTF-8";
 request.Timeout = 30 * 1000;
 var stream = request.GetRequestStream();
 using (var writer = new StreamWriter(stream))
 {
 writer.Write(jsonBody);
 writer.Flush();
 }
 HttpWebResponse response = (HttpWebResponse)request.GetResponse();
 string json = getResponseString(response);
 return JsonConvert.DeserializeObject<T>(json);
 }

 // REST @DELETE 方法 
 public static bool doDeleteMethod(string url)
 {
 HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
 request.Method = "delete";
 request.ContentType = "application/json;charset=UTF-8";
 HttpWebResponse response = (HttpWebResponse)request.GetResponse();
 using (StreamReader reader = new StreamReader(response.GetResponseStream(), System.Text.Encoding.GetEncoding("UTF-8")))
 {
 string responseString = reader.ReadToEnd();
 if (responseString.Equals("1"))
 {
 return true;
 }
 return false;
 }
 } 
 }
}

/// <summary>
/// 取得升级服务端的url地址
/// </summary>
/// <returns></returns>
private String getServerUrl()
{
 String result = "";
 UpgraderClient upgraderClient = getUpgraderClient();
 if (upgraderClient != null)
 {
 result += "http://" + upgraderClient.serverIP +
 ":" + upgraderClient.serverPort +
 "/upgraderServer/service/upgrade.do";
 }
 return result;
}

/// <summary>
/// 测试与升级服务端的连接
/// </summary>
/// <returns></returns>
public bool testConnect()
{
 FileRequest fileReq = new FileRequest();
 fileReq.type = (int)RequestType.TEST_CONNECT;
 string jsonData = JsonConvert.SerializeObject(fileReq);
 FileResponse rep = null;
 try
 {
 rep = HttpClientUtil.doPostMethodToObj<FileResponse>(getServerUrl(), jsonData);
 } catch
 {
 throw new Exception("连接远程服务端失败！");
 }
 return rep.status == 200;
}