从同一应用程序中的另一个WebAPI调用WebApi

Question

I have several webAPIs developed in MVC WebAPI such as

public IHttpActionResult SendBroadcast(FinalPayload FinalPayload)

And I want to call another web api from inside this API. All my APIs are in the same application. The signature of the second API is

public IHttpActionResult SendMessage(Notifications)

From the first API i tried

this.SendMessage(Notifications)

and got error message something like reference to static object ....

I wanted to know if this way of calling webAPI is allowed or do I have to invoke a web client or similar such.

Any help in this will be much appreciated.

Answer 1

1st approach

You have to redesign the code in your application ie Solution.

• Create a class library project. Create an interface for the logic/functions which are common and consumed by different projects.
• Implement the interface in the class library project.
• In different projects(ie WebAPI projects) use the interface to access the common functionality.

2nd Approach

As thought by you, of-course you can create a web client to access the Web API in another project.

• Its not a good design and your problem is not ACTUALLY solved (just circumvented).
• Poor efficiency, as webclient will use http request to access the code in same solution.
• For future maintenance you may end up creating multiple web clients.

Answer 2

No, as usual you'll need to create a new web client in order to consume the API.

What @Marcus H has suggested in the comment is doable too, just wrap the logic inside second API into a separate method (be it instance or static) and invoke it from your first API will do the trick.

Answer 3

Yes you can. You can create a webClient in your controller method method2 that calls method1.

This is a little helper class you could use to help you:

namespace Api.Helpers
{
    public static class ApiHelpers
    {
        private static string HttpGet(string url)
        {
            WebRequest request = WebRequest.Create(url);
            request.Credentials = CredentialCache.DefaultCredentials;
            WebResponse response = request.GetResponse();
            Stream dataStream = response.GetResponseStream();
            StreamReader reader = new StreamReader(dataStream);
            string responseFromServer = reader.ReadToEnd();
            reader.Close();
            response.Close();
            return responseFromServer;
        }

        public static string HttpPostJson(string url, string json)
        {
            var httpWebRequest = (HttpWebRequest)WebRequest.Create(url);
            httpWebRequest.ContentType = "application/json";
            httpWebRequest.Method = "POST";

            using (var streamWriter = new StreamWriter(httpWebRequest.GetRequestStream()))
            {
                streamWriter.Write(json);
            }

            var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();
            using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
            {
                var result = streamReader.ReadToEnd();
                return result;
            };
        }
    }
}

If you want Cookie based authentication, then just use RestSharp instead. If you use Postman the Chrome extension tool, then if you can access your endpoint, you can automatically generate your C# code. Simply put the webclient code within the Controller method, and one API call will effectively chain to another.

so in your ApiController you'd write something like:

IHttpActionResult method1() {
    var result = ApiHelpers.HttpGet("http://thing.com/test");
    return Ok(result);
}