RestSharp用法小结

今天有空，小结一下RestSharp的用法。

RestSharp内置了XML和JSON的反序列化（deserializers ）。

• application/json – JsonDeserializer
• application/xml – XmlDeserializer
• text/json – JsonDeserializer
• text/xml – XmlDeserializer
• * – XmlDeserializer (all other content types not specified)

比如下面的实体类：

Public class Employee {
    Public string EmployeeId {get; set ;}
    Public int EmployeeName {get; set ;}
    Public int EmployeeAge {get ; set  ;}
}

对应的XML：

<Employee>
       < EmployeeId >1< /EmployeeId >
       < EmployeeName>John</ EmployeeName>
       < EmployeeAge>30</ EmployeeAge>
<Employee>

对应的JSON：

{
  EmployeeId:1
  EmployeeName:”John”
  EmployeeAge:30
}

1. 异步调用

client.ExecuteAsync(request, response => {
        Console.WriteLine(response.Content);
   });

2. 实现接口IRestAPIExecutor

using RestSharp;
using System;
using System.Threading.Tasks;

namespace myCompany
{
    public class RestAPIExecutor : IRestAPIExecutor
    {
        public string BaseUrl { get; set; }

        public string DefaultDateParameterFormat { get; set; }

        public IAuthenticator DefaultAuthenticator { get; set; }

        private RestClient client;

        public RestAPIExecutor(string CmsBaseURI, IAuthenticator Authenticator = null, string DateParameterFormat = null)
        {
            BaseUrl = CmsBaseURI;
            DefaultAuthenticator = Authenticator;

            client = new RestClient();

            if (DefaultAuthenticator != null)
                client.Authenticator = DefaultAuthenticator;

            if (DateParameterFormat != null)
                DefaultDateParameterFormat = DateParameterFormat;

            client.BaseUrl = BaseUrl;
        }

        public T GenericExecute<T>(RestRequest request) where T : new()
        {
            request.DateFormat = string.IsNullOrEmpty(DefaultDateParameterFormat) ? "yyyy-MM-dd HH:mm:ss" : DefaultDateParameterFormat;

            var response = client.Execute<T>(request);

            if (response.ErrorException != null)
            {
                throw new RestCallException("Error retrieving response.  Check inner details for more info.", response.ErrorException);
            } 

            return response.Data;
        }

        public RestRequestAsyncHandle AsyncGenericExecute<T>(RestRequest request, Action<IRestResponse<T>> action) where T : new()
        {
            request.DateFormat = string.IsNullOrEmpty(DefaultDateParameterFormat) ? "yyyy-MM-dd HH:mm:ss" : DefaultDateParameterFormat;
            return client.ExecuteAsync<T>(request, action);
        }

        public Task<T> GetTaskAsync<T>(RestRequest request) where T : new()
        {
            request.DateFormat = string.IsNullOrEmpty(DefaultDateParameterFormat) ? "yyyy-MM-dd HH:mm:ss" : DefaultDateParameterFormat;
            return client.GetTaskAsync<T>(request);
        }

        public IRestResponse Execute(RestRequest request)
        {
            request.DateFormat = string.IsNullOrEmpty(DefaultDateParameterFormat) ? "yyyy-MM-dd HH:mm:ss" : DefaultDateParameterFormat;

            var response = client.Execute(request);

            if (response.ErrorException != null)
            {
                throw new RestCallException("Error retrieving response.  Check inner details for more info.", response.ErrorException);
            }

            return response;
        }

        public byte[] DownloadData(RestRequest request)
        {
            return client.DownloadData(request);
        }

    }
}

3. 实现自己的业务逻辑，包括

• HTTP GET，返回JSON，自动反序列化为实体类
• HTTP GET，获得返回的XML字符串，并转为XDocument
• 获得返回的http header里面的字段
• HTTP POST, 提交一个zip包
• HTTP GET, Partial download, 分段下载大的内容，可能包含很多个请求。最后还需要另外发一个请求获得整个文件的SHA码

using System.Xml.Linq;
using RestSharp;
using System;
using System.Configuration;
using System.IO;
using System.Linq;

namespace myCompany
{
    public class myClient
    {
        #region Initialization

        private readonly IRestAPIExecutor restAPIExecutor;

        public myClient()
        {
            restAPIExecutor = new RestAPIExecutor(ConfigurationManager.AppSettings[Utility.Constants.Configuration.CmsBaseUri],
               DateParameterFormat: ConfigurationManager.AppSettings[Utility.Constants.Configuration.DateFormat]);
        }

        public myClient(string CmsBaseURI, string dateFormat, string username = null, string password = null)
        {
            restAPIExecutor = !string.IsNullOrEmpty(username) ? new RestAPIExecutor(CmsBaseURI, DateParameterFormat: dateFormat, Authenticator: new HttpBasicAuthenticator(username, password)) : new RestAPIExecutor(CmsBaseURI, DateParameterFormat: dateFormat);
        }

        #endregion

        //HTTP GET，返回JSON，自动反序列化为实体类
        public OrderResult GetOrders(DateTime date, string channel = null, string merchant = null, string venue = null)
        {
            var request = new RestRequest(ConfigurationManager.AppSettings[Utility.Constants.Configuration.API_Campaign_List], Method.GET);
            request.AddParameter("date", string.Format("{0:yyyy-MM-dd}", date));
            if (!string.IsNullOrEmpty(channel)) request.AddParameter("channel", channel);
            if (!string.IsNullOrEmpty(merchant)) request.AddParameter("merchant", merchant);
            if (!string.IsNullOrEmpty(venue)) request.AddParameter("venue", venue);

            return restAPIExecutor.GenericExecute<OrderResult>(request);
        }

        //HTTP GET，获得返回的XML字符串，并转为XDocument
        public XDocument GetOrderDetailsXml(int OrderID)
        {
            var request = new RestRequest(ConfigurationManager.AppSettings[Utility.Constants.Configuration.API_Order_Details], Method.GET);
            request.AddHeader(Application.AcceptHttpHeader, Application.AcceptHttpHeaderValue);
            request.AddParameter("OrderID", OrderID.ToString(), ParameterType.UrlSegment);
            var response = restAPIExecutor.Execute(request);

            //获得返回的http header里面的字段
            //var sha = response.Headers.Where(s => s.Name == Application.SHAHttpHeader).Select(s => s.Value).FirstOrDefault();

            return XDocument.Parse(response.Content);
        }

        //HTTP POST, 提交一个zip包
        public IRestResponse UploadZipFile(string fileName, byte[] fileContent)
        {
            var request = new RestRequest(ConfigurationManager.AppSettings[Utility.Constants.Configuration.API_POP_ZIP_Upload], Method.POST);
            request.AddHeader("Content-Type", "application/zip");
            request.AddParameter("filename", fileName);
            request.AddFile("gzip", fileContent, fileName, "application/zip");

            return restAPIExecutor.Execute(request);
        }

        //HTTP GET, Partial download, 分段下载大的内容，可能包含很多个请求。最后还需要另外发一个请求获得整个文件的SHA码
        public byte[] DownloadPartialOrderMedia()
        {
        	var request = new RestRequest(ConfigurationManager.AppSettings[Utility.Constants.Configuration.API_POP_ZIP_Upload], Method.POST);
            request.AddParameter("filename", fileName);
            return restAPIExecutor.DownloadData(request);
        }

    }
}

3. 异步读取RESTful API

var client = new RestClient("http://example.org");
var request = new RestRequest("product/42", Method.GET);
var content = await client.GetContentAsync(request);

扩展方法：

using System;
using System.Threading.Tasks;
using RestSharp;

namespace RestSharpEx
{
    public static class RestClientExtensions
    {
        private static Task<T> SelectAsync<T>(this RestClient client, IRestRequest request, Func<IRestResponse, T> selector)
        {
            var tcs = new TaskCompletionSource<T>();
            var loginResponse = client.ExecuteAsync(request, r =>
            {
                if (r.ErrorException == null)
                {
                    tcs.SetResult(selector(r));
                }
                else
                {
                    tcs.SetException(r.ErrorException);
                }
            });
            return tcs.Task;
        }

        public static Task<string> GetContentAsync(this RestClient client, IRestRequest request)
        {
            return client.SelectAsync(request, r => r.Content);
        }

        public static Task<IRestResponse> GetResponseAsync(this RestClient client, IRestRequest request)
        {
            return client.SelectAsync(request, r => r);
        }
    }
}