如何使用ktor库和kotlin下载.apk？

dependencies {
    implementation "io.ktor:ktor-server-core:$ktor_version"
    implementation "io.ktor:ktor-server-netty:$ktor_version"
}

import io.ktor.application.*
import io.ktor.features.ContentDisposition
import io.ktor.http.HttpHeaders
import io.ktor.http.HttpStatusCode
import io.ktor.http.content.*
import io.ktor.response.respond
import io.ktor.routing.*
import io.ktor.server.engine.embeddedServer
import io.ktor.server.netty.Netty

fun main() {
    embeddedServer(Netty, port = 8080) {
        routing {
            get("/download") {
                val apkFile = // 你要下载的.apk文件
                call.respond(
                    object : OutgoingContent.WriteChannelContent() {
                        override suspend fun writeTo(channel: ByteWriteChannel) {
                            val inputStream = apkFile.inputStream()
                            channel.writeAvailable(inputStream.readBytes())
                            inputStream.close()
                        }

                        override val contentLength: Long = apkFile.length()
                        override val contentType = ContentType.Application.OctetStream.withParameter(
                            HttpHeaders.ContentDisposition,
                            ContentDisposition.Attachment.withParameter(
                                ContentDisposition.Parameters.FileName,
                                apkFile.name
                            ).toString()
                        )
                    }
                )
            }
        }
    }.start(wait = true)
}