在C#中使用JSON消费RESTful Web服务

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在C#中使用JSON消费RESTful Web服务

这是我目前的代码:\n

public class Class1
{
    private const string URL = "https://sub.domain.com/objects.json?api_key=123";
    private const string DATA = @"{""object"":{""name"":""Name""}}";
    
    static void Main(string[] args)
    {
        Class1.CreateObject();
    }
    
    private static void CreateObject()
    {
        try 
        {
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(URL);
            request.Method = "POST";
            request.ContentType = "application/json";
            request.ContentLength = DATA.Length;
            
            using (StreamWriter requestWriter = new StreamWriter(request.GetRequestStream(), System.Text.Encoding.ASCII))
            {
                requestWriter.Write(DATA);
            }
            
            using (WebResponse webResponse = request.GetResponse())
            {
                using (Stream webStream = webResponse.GetResponseStream())
                {
                    using (StreamReader responseReader = new StreamReader(webStream))
                    {
                        string response = responseReader.ReadToEnd();
                        Console.Out.WriteLine(response);
                    }
                }
            }
        }
        catch (Exception e)
        {
            Console.Out.WriteLine("-----------------");
            Console.Out.WriteLine(e.Message);
        }
    }
}

\n问题在于我认为异常块被触发了(因为当我移除try-catch时,我会得到一个服务器错误(500)的消息)。但是我没有看到我放在catch块中的Console.Out行。\n我的控制台输出:\n

The thread 'vshost.NotifyLoad' (0x1a20) has exited with code 0 (0x0).
The thread '' (0x1988) has exited with code 0 (0x0).
The thread 'vshost.LoadReference' (0x1710) has exited with code 0 (0x0).
'ConsoleApplication1.vshost.exe' (Managed (v4.0.30319)): Loaded 'c:\users\l. preston sego iii\documents\visual studio 11\Projects\ConsoleApplication1\ConsoleApplication1\bin\Debug\ConsoleApplication1.exe', Symbols loaded.
'ConsoleApplication1.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\Microsoft.Net\assembly\GAC_MSIL\System.Configuration\v4.0_4.0.0.0__b03f5f7f11d50a3a\System.Configuration.dll', Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled.
A first chance exception of type 'System.Net.WebException' occurred in System.dll
The thread 'vshost.RunParkingWindow' (0x184c) has exited with code 0 (0x0).
The thread '' (0x1810) has exited with code 0 (0x0).
The program '[2780] ConsoleApplication1.vshost.exe: Program Trace' has exited with code 0 (0x0).
The program '[2780] ConsoleApplication1.vshost.exe: Managed (v4.0.30319)' has exited with code 0 (0x0).

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问题的原因是发起的HTTP请求返回了404错误,即资源未找到。解决方法是在发起请求前添加Authorization头部,将token作为Bearer凭证传递。

文章内容如下:

在使用C#消费一个带有JSON的RESTful web服务时,我们需要注意以下几点。首先,我们需要确保使用using语句块来正确地释放IDisposable对象。具体代码如下:

using System;
using System.Net;
using System.IO;
namespace ConsoleProgram
{
    public class Class1
    {
        private const string URL = "https://sub.domain.com/objects.json?api_key=123";
        private const string DATA = @"{""object"":{""name"":""Name""}}";
        static void Main(string[] args)
        {
            Class1.CreateObject();
        }
        private static void CreateObject()
        {
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(URL);
            request.Method = "POST";
            request.ContentType = "application/json";
            request.ContentLength = DATA.Length;
            using (Stream webStream = request.GetRequestStream())
            using (StreamWriter requestWriter = new StreamWriter(webStream, System.Text.Encoding.ASCII))
            {
                requestWriter.Write(DATA);
            }
            try
            {
                WebResponse webResponse = request.GetResponse();
                using (Stream webStream = webResponse.GetResponseStream() ?? Stream.Null)
                using (StreamReader responseReader = new StreamReader(webStream))
                {
                    string response = responseReader.ReadToEnd();
                    Console.Out.WriteLine(response);
                }
            }
            catch (Exception e)
            {
                Console.Out.WriteLine("-----------------");
                Console.Out.WriteLine(e.Message);
            }
        }
    }
}

注意,我们需要添加Authorization头部,将token作为Bearer凭证传递。具体代码如下:

request.Headers.Add("Authorization", "Bearer " + token);

这样就可以使用token进行身份验证/登录,并使用GET方法获取数据了。

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使用RestSharp和JSON.NET是一个明智的选择。我发现微软的工具集在某些方面还不够完善,可能会出现故障。

另一个支持RestSharp的原因是它可以更容易地进行测试,比WebApi客户端库要容易得多。

对于使用mono的用户来说,RestSharp似乎使用的是System.Net WebRequest API,根据我的经验,它不如.net的实现可靠。(随机的卡死)

这里需要一个示例。

RestSharp的默认JSON反序列化器不如JSON.NET强大。

关于RestSharp需要注意一点。我发现虽然它似乎使用了语义化版本控制,但实际上并没有,当我从一个版本升级到另一个版本时,很多时候会遇到破坏性的更改(接口更改/移除),而版本号表明该更改只是修复bug。

你可以覆盖默认的反序列化器:github.com/restsharp/RestSharp/wiki/Deserialization

缺少示例使得这个帖子不够有用!

我发现RestSharp的反序列化器不支持数组,但对于List来说效果非常好!

请注意,截至我撰写本评论时,RestSharp团队仍然存在套接字耗尽问题:github.com/restsharp/RestSharp/issues/1322

以上是关于如何在C#中使用JSON消费RESTful web服务的一些讨论和建议。使用RestSharp和JSON.NET是一个可行的解决方案,它们提供了更简洁和强大的方式来处理REST服务的调用和响应数据的解析。此外,还注意到RestSharp的一些限制和问题,例如默认的JSON反序列化器的能力不如JSON.NET强大,以及可能会遇到版本升级时的破坏性更改。使用RestSharp和JSON.NET可以提高代码的易用性和健壮性。

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问题:如何使用C#和JSON消费一个RESTful web服务?

原因:ASP.NET Web API已经取代了之前提到的WCF Web API。根据微软的最新指南,建议使用Microsoft ASP.NET Web API客户端库来消费RESTful服务。这个库可以通过NuGet包Microsoft.AspNet.WebApi.Client进行安装。

解决方法:首先,在解决方案中添加Microsoft.AspNet.WebApi.Client NuGet包。然后,使用ASP.NET Web API客户端库实现如下代码:

using System;
using System.Collections.Generic;
using System.Net.Http;
using System.Net.Http.Headers;
namespace ConsoleProgram
{
    public class DataObject
    {
        public string Name { get; set; }
    }
    public class Class1
    {
        private const string URL = "https://sub.domain.com/objects.json";
        private string urlParameters = "?api_key=123";
        static void Main(string[] args)
        {
            HttpClient client = new HttpClient();
            client.BaseAddress = new Uri(URL);
            // Add an Accept header for JSON format.
            client.DefaultRequestHeaders.Accept.Add(
            new MediaTypeWithQualityHeaderValue("application/json"));
            // List data response.
            HttpResponseMessage response = client.GetAsync(urlParameters).Result;  // Blocking call! Program will wait here until a response is received or a timeout occurs.
            if (response.IsSuccessStatusCode)
            {
                // Parse the response body.
                var dataObjects = response.Content.ReadAsAsync>().Result;  //Make sure to add a reference to System.Net.Http.Formatting.dll
                foreach (var d in dataObjects)
                {
                    Console.WriteLine("{0}", d.Name);
                }
            }
            else
            {
                Console.WriteLine("{0} ({1})", (int)response.StatusCode, response.ReasonPhrase);
            }
            
            // Make any other calls using HttpClient here.
            // Dispose once all HttpClient calls are complete. This is not necessary if the containing object will be disposed of; for example in this case the HttpClient instance will be disposed automatically when the application terminates so the following call is superfluous.
            client.Dispose();
        }
    }
}

请注意,在多次请求时,应该重复使用HttpClient实例,而不是创建新的实例。为了更好地管理资源,请使用using语句将HttpClient声明包装起来。

以上是问题“如何使用C#和JSON消费一个RESTful web服务?”的原因和解决方法。如果需要更多详情,请参考微软官方文档《从.NET客户端(C#)调用Web API》和相关的博客文章。

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