Can one post binary data (not multipart) from a `java.io.File` like this? ```val channel = file.read...

# ktor

[natario1]

Can one post binary data (not multipart) from a java.io.File like this?

val channel = file.readChannel()
return <http://ktor.post|ktor.post>("endpoint") {
    setBody(channel)
    contentType(ContentType.Application.OctetStream)
}.body()

Server returns 500 and I’m trying to understand if it’s my fault or not. I found readChannel() by accident, but it seemed useful in order to avoid loading the whole file in JVM memory as a ByteArray for example.

[natario1]

Another Channel-related test (as said, I’m not confident with the interface, just playing with it):

setBody(ChannelWriterContent(
    contentType = contentType,
    body = {
        val read = file.readChannel()
        read.copyTo(this)
    }
))

It fails too. setBody(file.readBytes()) works.

[Aleksei Tirman [JB]]

The following code works on my machine:

val channel = File("path/to/file").readChannel()
val client = HttpClient()
val response = <http://client.post|client.post>("<https://httpbin.org/post>") {
    setBody(channel)
    contentType(ContentType.Application.OctetStream)
}
println(response.bodyAsText())

[natario1]

Thanks Aleksei, I have the same code. If I replace readChannel() with readBytes(), our server is happy, otherwise it isn’t. So this line creates some difference in the outgoing request, but I can’t figure out what

[Aleksei Tirman [JB]]

Maybe the problem is that in case of the readChannel the Transfer-Encoding: chunked header is sent.

[natario1]

I see, that’s likely the problem… FWIW I tried passing contentLength to ChannelWriterContent, to avoid the chunked transfer. But backend is still unhappy. Now I don’t think I have more time to spend on this 😄 thank you anyway!