使用Javascript在content-disposition头中设置size参数

Question

The Problem

I've been trying to set the size parameter in the content-disposition header for quite some time.

function uploadFile(file) {
    const data = new FormData();
    data.append('file', file);

    axios.post('url/of/endpoint', data);

FormData does not send the size parameter by default and, to my knowledge, I can't see a way of setting it myself. Is there a way of doing this with Axios? Do I need to go more lower level and build my own headers?

The Context

My primary objective is to pipe a file input stream via a Java endpoint to S3. But without the file size, all of the data gets loaded into memory and has a high chance of causing an OOM exception. This specific problem has been asked here as well . Is writing my own byte buffer the only way? Should I just stop being lazy and do that? Seems like an overly-complex solution...

Is there a reason as to why the file size isn't normally included in FormData? I've tried using Content-Length, but that includes the content-disposition header and leads to a mismatched byte count.

Answer 1

Right, so after going around the office... then to my friends... I come to the conclusion that this is a Java shortcoming. Well, not the original question, but the fact that a multipart upload requires the total file size. So, the implementation I'm currently going with, which makes me feel super dirty, is adding a FormData item size on the client side.

function uploadFile(file) {
    const data = new FormData();
    data.append('size', file.size.toString());
    data.append('file', file);

    axios.post('url/of/endpoint', data);

And then updating the backend to pass that size to the S3 SDK... ... oof.