Why Use Httpclient for Synchronous Connection

What's the right way to use HttpClient synchronously?

For anyone coming across this now, .NET 5.0 has added a synchronous Send method to HttpClient. https://github.com/dotnet/runtime/pull/34948

You can therefore use this instead of SendAsync. For example

public string GetValue()
{
    var client = new HttpClient();
            
    var webRequest = new HttpRequestMessage(HttpMethod.Post, "http://your-api.com")
    {
        Content = new StringContent("{ 'some': 'value' }", Encoding.UTF8, "application/json")
    };

    var response = client.Send(webRequest);

    using var reader = new StreamReader(response.Content.ReadAsStream());
            
    return reader.ReadToEnd();
}

This code is just a simplified example, it's not production ready.

Why use HttpClient for Synchronous Connection

For anyone coming across this now, .NET 5.0 has added a synchronous Send method to HttpClient. https://github.com/dotnet/runtime/pull/34948

The merits as to why where discussed at length here: https://github.com/dotnet/runtime/issues/32125

You can therefore use this instead of SendAsync. For example

public string GetValue()
{
    var client = new HttpClient();
            
    var webRequest = new HttpRequestMessage(HttpMethod.Post, "http://your-api.com")
    {
        Content = new StringContent("{ 'some': 'value' }", Encoding.UTF8, "application/json")
    };

    var response = client.Send(webRequest);

    using var reader = new StreamReader(response.Content.ReadAsStream());
            
    return reader.ReadToEnd();
}

This code is just a simplified example - it's not production ready.

Why use HttpClient over HttpWebRequest for synchronous requests

HttpClient is designed to give more control over http protocol, where else doing same in HttpWebRequest or WebClient was not that straight forward. Apart from asynchronous, there are many benefits of HttpClient

Benefits of HttpClient

Biggest benefit of HttpClient is plugin architecture, that lets you change underlying behavior of HTTP protocol easily.

1. HttpClient is extensible, underlying HttpMessageHandler allows you to completely by pass underlying Microsoft's HttpClient implementation and you can plugin your own implementation. For example, in iOS and Android, instead of using .Net's HttpClient, we could use native Http stack.
2. It is easy to replace caching, cookies by customizing HttpMessageHandler
3. CancellationToken support is excellent when we want to cancel a long running Http request.
4. Not shiny, but important, Multi threaded, HttpClient is optimized to manage multiple requests with single instance. CPU time is utilized very efficiently without using too many locks (synchronous operations depend on locks, which is considerable overhead on CPU). Today we are living in world of micro services. In server with many clients to serve and mobile OS, CPU time is costly.

Drawbacks

Only drawback is async/await, you can't simply use async libraries easily in synchronous code without using a Task Runner or deadlocks. Though there are many libraries supporting how to synchronously use async code.

There is no great benefit of HttpClient on Desktop application with lots of CPU time as spare.

best way to use the nice .net 4.5 HttpClient synchronously

From http://blogs.msdn.com/b/pfxteam/archive/2012/04/13/10293638.aspx:

return Task.Run(() => Client.PostAsync()).Result;

---

Related Topics