我正在尝试使用akka http实现简单的文件上传。
我的尝试如下所示:
import akka.actor.ActorSystem
import akka.event.{LoggingAdapter, Logging}
import akka.http.scaladsl.Http
import akka.http.scaladsl.model.{HttpResponse, HttpRequest}
import akka.http.scaladsl.model.StatusCodes._
import akka.http.scaladsl.server.Directives._
import akka.stream.{ActorMaterializer, Materializer}
import com.typesafe.config.Config
import com.typesafe.config.ConfigFactory
import scala.concurrent.{ExecutionContextExecutor, Future}
import akka.http.scaladsl.model.StatusCodes
import akka.http.scaladsl.model.HttpEntity
import java.io._
import akka.stream.io._
object UploadTest extends App {
implicit val system = ActorSystem()
implicit val executor = system.dispatcher
implicit val materializer = ActorMaterializer()
val config = ConfigFactory.load()
val logger = Logging(system, getClass)
val routes = {
pathSingleSlash {
(post & extractRequest) {
request => {
val source = request.entity.dataBytes
val outFile = new File("/tmp/outfile.dat")
val sink = SynchronousFileSink.create(outFile)
source.to(sink).run()
complete(HttpResponse(status = StatusCodes.OK))
}
}
}
}
Http().bindAndHandle(routes, config.getString("http.interface"), config.getInt("http.port"))
}
此代码存在多个问题:
Request Content-Length 24090745 exceeds the configured limit of 8388608
dead letters encountered.
异常。 克服大小限制的最佳方法是什么?如何正确关闭文件,以便后续的上载会覆盖现有文件(暂时忽略并发上载)?
最佳答案
对于第2点,我认为source.to(sink).run()
可异步执行该操作。它实现了Future
。因此,您的HTTP请求可能会在文件写入完成之前返回,因此,如果在第一个请求返回后立即在客户端开始第二次上载,则第一个请求可能尚未完成对文件的写入。
您可以使用onComplete
或onSuccess
指令仅在将来完成时完成http请求:
http://doc.akka.io/docs/akka-stream-and-http-experimental/1.0-M2/scala/http/directives/alphabetically.html
http://doc.akka.io/docs/akka-stream-and-http-experimental/1.0/scala/http/routing-dsl/directives/future-directives/onSuccess.html
编辑:
对于内容长度问题,您可以做的一件事就是增加application.conf
中该属性的大小。默认值为:
akka.server.parsing.max-content-length = 8m
参见http://doc.akka.io/docs/akka-stream-and-http-experimental/1.0/java/http/configuration.html
关于scala - Akka-HTTP : File Upload,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/32924813/