Return JSON file with ASP.NET Web API

Question

I am trying to return a JSON file using ASP.NET Web API (for testing).

public string[] Get()
{
    string[] text = System.IO.File.ReadAllLines(@"c:\data.json");

    return text;
}

In Fiddler this does appear as a Json type but when I debug in Chrome and view the object it appears as and array of individual lines (left). The right image is what the object should look like when I am using it.

Can anyone tell me what I should return to achieve a Json result in the correct format?

http://stackoverflow.com/questions/9847564/how-do-i-get-asp-net-web-api-to-return-json-instead-of-xml-using-chrome..May help you! — ssilas777, Mar 31 '13 at 03:55
@ssilas777 I don't think that's the same question. That's about returning XML vs. JSON as opposed to returning incorrect JSON. — Eilon, Mar 31 '13 at 03:58

score 31 · Accepted Answer · edited May 08 '16 at 14:31

31

Does the file already has valid JSON in it? If so, instead of calling File.ReadAllLines you should call File.ReadAllText and get it as a single string. Then you need to parse it as JSON so that Web API can re-serialize it.

public object Get()
{
    string allText = System.IO.File.ReadAllText(@"c:\data.json");

    object jsonObject = JsonConvert.DeserializeObject(allText);
    return jsonObject;
}

This will:

Read the file as a string
Parse it as a JSON object into a CLR object
Return it to Web API so that it can be formatted as JSON (or XML, or whatever)

edited May 08 '16 at 14:31

ojhawkins

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answered Mar 31 '13 at 03:56

Eilon

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how would one do this if the .JSON file would be an uri and not on c:, the file does not accept an uri as input – Ewald Bos Jun 25 '18 at 19:28

ojhawkins · Answer 2 · 2016-05-08T08:29:08.520

23

I found another solution which works also if anyone was interested.

public HttpResponseMessage Get()
{
    var stream = new FileStream(@"c:\data.json", FileMode.Open);

    var result = Request.CreateResponse(HttpStatusCode.OK);
    result.Content = new StreamContent(stream);
    result.Content.Headers.ContentType = new MediaTypeHeaderValue("application/json");

    return result;
}

edited May 08 '16 at 08:29

answered Mar 31 '13 at 04:02

ojhawkins

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The generic HttpResponseMessage is now deprecated as it wasn't Type safe.. http://stackoverflow.com/questions/10655350/returning-http-status-code-from-asp-net-mvc-4-web-api-controller – Markive May 08 '13 at 01:36
4

+1: The HttpResponseMessage may be deprecated, but it worked in the situation where the JSON property names were not valid CLR (e.g. had spaces in them). Your answer gave me the clue I needed to return generated raw text as JSON. Thanks – iCollect.it Ltd Jul 01 '13 at 07:34

score 5 · Answer 3 · edited May 23 '17 at 11:47

I needed something similar, but IHttpActionResult (WebApi2) was required.

public virtual IHttpActionResult Get()
{
    var result = new System.Net.Http.HttpResponseMessage(System.Net.HttpStatusCode.OK)
    {
        Content = new System.Net.Http.ByteArrayContent(System.IO.File.ReadAllBytes(@"c:\temp\some.json"))
    };

    result.Content.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("application/json");
    return ResponseMessage(result);
}

Return JSON file with ASP.NET Web API

3 Answers3