Kotlin Ktor http客户端-请求进度

如何监视Ktor http客户端中的请求进度

例如：我有这样的请求：

val response = HttpClient().get<String>("https://stackoverflow.com/")

fun progress(downloaded: Long, contentLength: Long) {
    // Update progress bar or whatever
}

如何设置HttpClient调用的

progress（）

编辑：这是Kotlin多平台项目。相关依赖项包括：

implementation 'io.ktor:ktor-client-core:1.2.5'
implementation 'io.ktor:ktor-client-cio:1.2.5'

---

在从Ktor 1.6.0开始的Ktor中，您可以使用

HttpRequestBuilder

公开的扩展功能对下载进度更改作出反应：

val通道=获取（“https://ktor.io/") {
onDownload{bytesSentTotal，contentLength->
println（“从$contentLength接收到$bytesSentTotal字节”）
}
}

还有一个功能可用于显示上载进度：

onUpload{bytesSentTotal，contentLength->
println（“从$contentLength发送的$bytesSentTotal字节”）
}

以下是Ktor文档中的可运行示例：

val contentLength = // need to get via HEAD reqeuest 

suspend fun download() {
   val url = "https://stackoverflow.com/"
   val client = HttpClient()
   val channel = client.get<ByteReadChannel>(url)
   var total = 0
   var readBytes:Int
  
   var buffer = ByteArray(contentLength)
   do {
      readBytes = channel.readAvailable(buffer, total, 4096 )
      total+=readBytes
      progress(total, contentLength)
   } while (readBytes>0)
   val response = String(buffer)
}

suspend fun download() {
  val client = HttpClient()
  val builder = HttpRequestBuilder().apply {
    url("https://stackoverflow.com")
  }
  val httpStatement = HttpStatement(builder,  client)
  httpStatement.execute { response: HttpResponse ->
    // Response is not downloaded here
    val channel = response.receive<ByteReadChannel>()
    val contentLength = response.contentLength()
    requireNotNull(contentLength) {"Header needs to be set by server"}

    var total = 0
    var readBytes:Int
    var buffer = ByteArray(contentLength)  
    do {
      readBytes = channel.readAvailable(buffer, total, 4096 )
      total+=readBytes
      progress(total, contentLength)
    } while (readBytes>0)
      
    val response = String(buffer) 
  }
}

...
var buffer = ByteArray(4096) 
do {
   readBytes = channel.readAvailable(buffer, 0, 4096 )
   total+=readBytes
   writeToFile(buffer, readBytes) // do something sensible with the read bytes
   progress(total, response.contentLength())
} while (readBytes>0)
...