如何使用ktor上传单个位图图像？

import io.ktor.application.*
import io.ktor.http.*
import io.ktor.request.*
import io.ktor.response.*
import io.ktor.routing.*
import io.ktor.server.engine.*
import io.ktor.server.netty.*
import java.io.File

fun main() {
    embeddedServer(Netty, port = 8080) {
        routing {
            post("/upload") {
                val multipartData = call.receiveMultipart()
                multipartData.forEachPart { part ->
                    when (part) {
                        is PartData.FileItem -> {
                            val fileName = part.originalFileName as String
                            val fileBytes = part.streamProvider().readBytes()
                            val file = File("uploads/$fileName")
                            file.writeBytes(fileBytes)
                            call.respond(HttpStatusCode.OK, "File uploaded successfully: $fileName")
                        }
                        else -> {
                            part.dispose()
                        }
                    }
                }
            }
        }
    }.start(wait = true)
}