在HttpClient和WebClient之间做出决定

我们的网络应用程序在.Net Framework 4.0中运行.UI通过ajax调用调用控制器方法.

我们需要从供应商处使用REST服务.我正在评估在.Net 4.0中调用REST服务的最佳方法.REST服务需要基本身份验证方案,它可以返回XML和JSON中的数据.没有要求上传/下载大量数据,我将来也看不到任何东西.我看了几个用于REST消费的开源代码项目,并没有找到任何值来证明项目中的额外依赖性.开始评估WebClient和HttpClient.我从NuGet下载了用于.Net 4.0的HttpClient.

我搜索了WebClient和之间的差异,HttpClient并且该网站提到单个HttpClient可以处理并发调用,它可以重用已解析的DNS,cookie配置和身份验证.我还没有看到由于差异我们可能获得的实用价值.

我做了一个快速的性能测试,以找到WebClient(同步调用),HttpClient(同步和异步)如何执行.以下是结果:

HttpClient对所有请求使用相同的实例(min - max)

WebClient同步:8毫秒 - 167毫秒
HttpClient同步:3毫秒 - 7228毫秒
HttpClient异步:985 - 10405毫秒

HttpClient为每个请求使用new (min - max)

WebClient同步:4毫秒 - 297毫秒
HttpClient同步:3毫秒 - 7953毫秒
HttpClient异步:1027 - 10834毫秒

码

public class AHNData
{
    public int i;
    public string str;
}

public class Program
{
    public static HttpClient httpClient = new HttpClient();
    private static readonly string _url = "http://localhost:9000/api/values/";

    public static void Main(string[] args)
    {
       #region "Trace"
       Trace.Listeners.Clear();

       TextWriterTraceListener twtl = new TextWriterTraceListener(
           "C:\\Temp\\REST_Test.txt");
       twtl.Name = "TextLogger";
       twtl.TraceOutputOptions = TraceOptions.ThreadId | TraceOptions.DateTime;

       ConsoleTraceListener ctl = new ConsoleTraceListener(false);
       ctl.TraceOutputOptions = TraceOptions.DateTime;

       Trace.Listeners.Add(twtl);
       Trace.Listeners.Add(ctl);
       Trace.AutoFlush = true;
       #endregion

       int batchSize = 1000;

       ParallelOptions parallelOptions = new ParallelOptions();
       parallelOptions.MaxDegreeOfParallelism = batchSize;

       ServicePointManager.DefaultConnectionLimit = 1000000;

       Parallel.For(0, batchSize, parallelOptions,
           j =>
           {
               Stopwatch sw1 = Stopwatch.StartNew();
               GetDataFromHttpClientAsync>(sw1);
           });
       Parallel.For(0, batchSize, parallelOptions,
            j =>
            {
                Stopwatch sw1 = Stopwatch.StartNew();
                GetDataFromHttpClientSync>(sw1);
            });
       Parallel.For(0, batchSize, parallelOptions,
            j =>
            {
                using (WebClient client = new WebClient())
                {
                   Stopwatch sw = Stopwatch.StartNew();
                   byte[] arr = client.DownloadData(_url);
                   sw.Stop();

                   Trace.WriteLine("WebClient Sync " + sw.ElapsedMilliseconds);
                }
           });

           Console.Read();
        }

        public static T GetDataFromWebClient()
        {
            using (var webClient = new WebClient())
            {
                webClient.BaseAddress = _url;
                return JsonConvert.DeserializeObject(
                    webClient.DownloadString(_url));
            }
        }

        public static void GetDataFromHttpClientSync(Stopwatch sw)
        {
            HttpClient httpClient = new HttpClient();
            var response = httpClient.GetAsync(_url).Result;
            var obj = JsonConvert.DeserializeObject(
                response.Content.ReadAsStringAsync().Result);
            sw.Stop();

            Trace.WriteLine("HttpClient Sync " + sw.ElapsedMilliseconds);
        }

        public static void GetDataFromHttpClientAsync(Stopwatch sw)
        {
           HttpClient httpClient = new HttpClient();
           var response = httpClient.GetAsync(_url).ContinueWith(
              (a) => {
                 JsonConvert.DeserializeObject(
                    a.Result.Content.ReadAsStringAsync().Result);
                 sw.Stop();
                 Trace.WriteLine("HttpClient Async " + sw.ElapsedMilliseconds);
              }, TaskContinuationOptions.None);
        }
    }
}