前言
最近做了下个MVC的项目，需要用到rest接口，与java写的应用程序通信，包括数据的接收和发送，那么我将用实用的角度来全面的讲解一下它的使用方法
一、创建rest服务
首先创建一个Asp.Net Web应用程序（我这里用的是Visual Studio 2013，它已经内置了Web API2）。
在出来的模板中选择Empty（空项目），并勾选WebAPI。点击确定后，就创建了一个空的WebAPI服务。
此时只有一个空项目，还没有任何功能，在进行下一步之前，首先我们来看一下REST的基本操作模型，大致可以分为如下四种：
- POST — 创建资源
- GET — 检索资源
- PUT — 更新资源
- DELETE — 删除资源
非常经典的CRUD模型。在Web API中实现这样一个的模型是非常简单的，直接使用向导建一个Controller即可
如果用传统的向导，记得把向导后面的那个1给去掉：
默认的模板内容如下： ????public class ValuesController : ApiController ???{ ???????// GET api/<controller> ???????publicIEnumerable<string> Get() ???????{ ???????????returnnewstring[] { "value1", "value2" }; ???????} ???????// GET api/<controller>/5 ???????publicstring Get(int id) ???????{ ???????????return"value"; ???????} ???????// POST api/<controller> ???????publicvoid Post([FromBody]string value) ???????{ ???????} ???????// PUT api/<controller>/5 ???????publicvoid Put(int id, [FromBody]string value) ???????{ ???????} ???????// DELETE api/<controller>/5 ???????publicvoid Delete(int id) ???????{ ???????} ???}这其实已经帮我们实现了一个最基本的服务了，这样别人就可以访问我们的服务中的方法
二、调用其它应用程序的rest服务
1、RestClient类
为了便于使用，我们需要封装客房端的rest类，话不多说，我们直接上这个类的代码：
using System;using System.Collections.Generic;using System.IO;using System.Linq;using System.Net;using System.Text;using System.Web;namespace OilDigital.A2_A27.Web{ ???public class RestClient ???{ ???????public string EndPoint { get; set; } ???//请求的url地址 ????????public HttpVerb Method { get; set; } ???//请求的方法 ?????????public string ContentType { get; set; } //格式类型：我用的是application/json，text/xml具体使用什么，看需求吧 ?????????public string PostData { get; set; } ???//传送的数据，当然了我使用的是json字符串 ?????????public RestClient() ???????{ ???????????EndPoint = ""; ???????????Method = HttpVerb.GET; ???????????ContentType = "application/x-www-form-urlencoded"; ???????????PostData = ""; ???????} ???????public RestClient(string endpoint) ???????{ ???????????EndPoint = endpoint; ???????????Method = HttpVerb.GET; ???????????ContentType = "application/json"; ???????????PostData = ""; ???????} ???????public RestClient(string endpoint, HttpVerb method) ???????{ ???????????EndPoint = endpoint; ???????????Method = method; ???????????ContentType = "application/json"; ???????????PostData = ""; ???????} ???????public RestClient(string endpoint, HttpVerb method, string postData) ???????{ ???????????EndPoint = endpoint; ???????????Method = method; ???????????ContentType = "application/json"; ???????????PostData = postData; ???????} ???????public RestClient(string endpoint, HttpVerb method, string postData, string contentType) ???????{ ???????????EndPoint = endpoint; ???????????Method = method; ???????????ContentType = contentType; ???????????PostData = postData; ???????} ???????public string MakeRequest() ???????{ ???????????return MakeRequest(""); ???????} ???????public string MakeRequest(string parameters) ???????{ ???????????var request = (HttpWebRequest)WebRequest.Create(EndPoint + parameters); ???????????request.Method = Method.ToString(); ???????????request.ContentType = ContentType; ???????????????????????if (!string.IsNullOrEmpty(PostData) && Method == HttpVerb.POST)//如果传送的数据不为空，并且方法是post ?????????????{ ???????????????var encoding = new UTF8Encoding(); ?????????????????????var bytes = Encoding.GetEncoding("iso-8859-1").GetBytes(PostData);//编码方式按自己需求进行更改，我在项目中使用的是UTF-8 ?????????????????request.ContentLength = bytes.Length; ???????????????using (var writeStream = request.GetRequestStream()) ???????????????{ ???????????????????writeStream.Write(bytes, 0, bytes.Length); ???????????????} ???????????} ???????????if (!string.IsNullOrEmpty(PostData) && Method == HttpVerb.PUT)//如果传送的数据不为空，并且方法是put ?????????????{ ???????????????var encoding = new UTF8Encoding(); ???????????????var bytes = Encoding.GetEncoding("iso-8859-1").GetBytes(PostData);//编码方式按自己需求进行更改，我在项目中使用的是UTF-8 ?????????????????request.ContentLength = bytes.Length; ???????????????using (var writeStream = request.GetRequestStream()) ???????????????{ ???????????????????writeStream.Write(bytes, 0, bytes.Length); ???????????????} ???????????} ???????????using (var response = (HttpWebResponse)request.GetResponse()) ???????????{ ???????????????var responseValue = string.Empty; ???????????????if (response.StatusCode != HttpStatusCode.OK) ???????????????{ ???????????????????var message = String.Format("Request failed. Received HTTP {0}", response.StatusCode); ???????????????????throw new ApplicationException(message); ???????????????} ???????????????// grab the response ?????????????????using (var responseStream = response.GetResponseStream()) ???????????????{ ???????????????????if (responseStream != null) ???????????????????????using (var reader = new StreamReader(responseStream)) ???????????????????????{ ???????????????????????????responseValue = reader.ReadToEnd(); ???????????????????????} ???????????????} ???????????????return responseValue; ???????????} ???????} ???} ???public enum HttpVerb ???{ ???????GET, ???????????//method ?常用的就这几样，当然你也可以添加其他的 ??get：获取 ???post：修改 ???put：写入 ???delete：删除 ?????????POST, ???????PUT, ???????DELETE ???}}2、RestClient类使用
有了这个类后我们就很方便的去调用别人的rest服务了，使用方法如下：
1，基本的调用： var client = new RestClient();string endPoint = @"http:\\myRestService.com\api\";var client = new RestClient(endPoint);var json = client.MakeRequest(); 2，如果你想带入参数 var json = client.MakeRequest("?param=0"); 3，使用最多的方式 var client = new RestClient();client.EndPoint = @"http:\\myRestService.com\api\"; ;client.ContentType = "application/json";client.Method = HttpVerb.POST;client.PostData = "{postData: value}";var json = client.MakeRequest();三、我自己项目中的使用
1、首先我测试了一下，我调用我自己的rest服务的带参的get方法，当然我这里传的参数直接写在url的后面在，参数形式是string，所以接收的get方法的形参也要改成string,这样你就
可以接收到传过去的参数了。当然别人应用程序也是可以调的。只要把url给他就行了。
/// <summary> ???????/// 从接口中获取当前用户所有信息 ???????/// </summary> ???????/// <param name="userId">用户ID</param> ???????/// <returns>json对象</returns> ???????public string GetCurrentUserInfo() ???????{ ???????????string userId = GetCurrentUserId(); ???????????string endPoint = "http://localhost:100/Api/RestService/"+userId; ??????????var client = new RestClient(endPoint); ???????????var userInfo = client.MakeRequest(); ???????????return userInfo; ???????}2、接下来，我要开始试用java写的应用程序下的rest服务了，我通过我传过去的用户ID获取到了用户的所有信息，当然我在项目中使用了缓存技术，还将返回回来的json字符串转换成了json对象，以便我后面好用linq对其进行操作，关于linq to json 可以参考我的linq专题相关文章 ，我在项目中的代码是酱子的：
/// <summary> ???????/// 从接口中获取用户所有信息 ???????/// </summary> ???????/// <param name="userId">用户ID</param> ???????/// <returns></returns> ???????public static JObject CacheUser() ???????{ ???????????try ???????????{ ???????????????string currentUser = GetCurrentUserId(); ???????????????if (HttpRuntime.Cache.Get("user$" + GetCurrentUserId()) == null) ???????????????{ ???????????????????string endPoint = "http://66.66.66.666:6666/DASBASE/restServices/dataCollectionService/getUserPermissions"; ???????????????????string postData = "jsonData={\"userCode\": \"kfry\",\"systemId\": \"1E1A7AC94BFC41D4BEBED8942EB69689\"}"; ???????????????????var client = new RestClient(endPoint, HttpVerb.POST, postData, "application/x-www-form-urlencoded"); ???????????????????var u = client.MakeRequest(); ???????????????????JObject userInfo = JObject.Parse(u); ???????????????????//插入缓存 ???????????????????HttpRuntime.Cache.Insert("user$" + currentUser, userInfo, null, System.DateTime.UtcNow.AddMinutes(30), TimeSpan.Zero); ???????????????} ???????????????return (JObject)HttpRuntime.Cache.Get("user$" + GetCurrentUserId()); ???????????} ???????????catch (Exception ex) ???????????{ ???????????????throw new ApplicationException("获取用户信息出错："+ex.Message); ???????????} ???????}asp.net MVC下使用rest
原文地址：http://www.cnblogs.com/zhengwei-cq/p/7530348.html