Multipart body length limit 16384 exceeded

Question

I've been trying to get this to work, but to no avail.

What I am trying to do, is to upload a set of FormData images and attachments using JQuery AJAX.

I keep getting the error: "Multipart body length limit 16384 exceeded"

I found another similar question here on SO: Multipart body length limit exceeded exception

If anyone here can help me out or point me in a direction, that would be greatly appreciated. It's almost midnight on my side, and I'm about to give up :(.

I am using ASP.NET Core 1.1.

Here is my javascript:

let data = new FormData();
    data.enctype = "multipart/form-data";
    let file = $("#imgItem_image-upload-file")[0].files[0];

    data.append("image|" + file.name, file); //Works fine if alone.

    //Does not work, causes error on server side.
    for (var i = 0; i < objItem.Attachments[0].length; i++) {
        let attFile = objItem.Attachments[0][i].File;
        console.log(attFile);
        data.append("attachment|" + attFile.name, attFile);
    }

    data.append("Category", objItem.Category);
    data.append("NewCategory", objItem.NewCategory);
    data.append("Name", objItem.Name);
    data.append("IdentificationType", objItem.IdentificationType);
    data.append("SerialNumber", objItem.SerialNumber);
    data.append("IMEI", objItem.IMEI);
    data.append("EngineNumber", objItem.EngineNumber);
    data.append("MASNumber", objItem.MASNumber);
    data.append("NumberPlate", objItem.NumberPlate);
    data.append("VINNumber", objItem.VINNumber);
    data.append("Description", objItem.Description);
    $.ajax({
        url: "http://localhost:7001/api/AddPersonalItem",
        type: "POST",
        data: data,
        //dataType: "json",
        //headers: { 'Content-Type': false },
        //contentType: false,
        contentType: false, //'multipart/form-data'
        processData: false,
        // headers: { 
        //     'Accept': 'application/json',
        //     'Content-Type': 'application/json' 
        // },
        success: function (response) {

        },
        error: function(jqXHR, textStatus, errorThrown) {
            console.log(textStatus, errorThrown);
        }
    });

I also added this to my Startup.js file:

    public void ConfigureServices(IServiceCollection services)
    {
        // Add framework services.
        services.AddMvc();

        //Multipart
        services.Configure<FormOptions>(x =>
        {
            x.MultipartBodyLengthLimit = 60000000;
        });
    }

And here is my API Controller's code:

        public ServiceCallResponse AddPersonalItem()
        {
            ItemObject io = new ItemObject();
            io.Attachments = new List<Attachment>();
            io.Image = new Image();

            //Get files.
            foreach (IFormFile file in Request.Form.Files)
            {
                //The file name also states what type of object this is.
                string type = file.Name.Split('|')[0];
                string name = file.Name.Split('|')[1];

                StreamReader reader = new StreamReader(file.OpenReadStream());
                byte[] bytes = Encoding.Unicode.GetBytes(reader.ReadToEnd());
                string base64 = Convert.ToBase64String(bytes);

                switch (type.ToLower().Trim())
                {
                    case "attachment":
                        Attachment a = new Attachment();
                        a.Name = name;
                        a.Base64 = base64;

                        io.Attachments.Add(a);
                        break;
                    case "image":
                        io.Image.Name = name;
                        io.Image.Base64 = base64;
                        break;
                }
            }
        }

Even after increasing the multipart body length, i am still getting the exact same error.

The error occurs on:

foreach (IFormFile file in Request.Form.Files)

If I am not clear enough n this, please ask and I'll try to ellaborate! :)

Answer 1

In my case the solution was to increase MemoryBufferThreshold.

services.Configure<FormOptions>(options =>
{
    options.MemoryBufferThreshold = Int32.MaxValue;
});

Answer 2

I got the exception and I found that my client had a incorrect HTTP header "content-type". Using curl with the incorrect input type curl tried to send the entire file in the POST Body as text, not a great move :-)

Example with curl: This failed:

curl --request POST \
  --url https://stuff.net/api/storage \
  --header 'authorization: bearer MY_ACCESS_TOKEN' \
  --header 'cache-control: no-cache' \
  --header 'content-type: multipart/form-data; boundary=----WebKitFormBoundary7MA4YWxkTrZu0gW' \
  --form MyfileName=b72871d79c81 \
  --form [email protected] \
  --form MyfileId=9401c94db46c

This worked:

curl --request POST \
  --url https://stuff.net/api/storage \
  --header 'authorization: bearer MY_ACCESS_TOKEN' \
  --header 'cache-control: no-cache' \
  --form MyfileName=b72871d79c81 \
  --form [email protected] \
  --form MyfileId=9401c94db46c

Answer 3

You need to increase the value length limit as well. Default is like 4MB.

              services.Configure<FormOptions>(options =>
                {
                    options.ValueCountLimit = 10; //default 1024
                    options.ValueLengthLimit = int.MaxValue; //not recommended value
                    options.MultipartBodyLengthLimit = long.MaxValue; //not recommended value
                });