将 index.html 作为 Akka HTTP 的 getFromDirectory 中的默认文件 [英] Treat index.html as default file in Akka HTTP's getFromDirectory

问题描述

假设我有一个文件夹 foo，其中包含一个 index.html 文件，以及下面用于 Akka HTTP 的以下最小(但很可能不起作用)服务器代码:

Assuming I have a folder foo with an index.html file in it and the following minimal (but most likely not functional) server code for Akka HTTP below:

object Server extends App {
  val route: Route =
    pathPrefix("foo") {
      getFromDirectory("foo")
    }

  Http().bindAndHandle(route, "0.0.0.0", 8080)
}

如果我在浏览器中打开 http://localhost:8080/foo/index.html 将正确提供

index.html，但如果我打开 <代码>http://localhost:8080/foo 或 http://localhost:8080/foo/.

index.html will correctly be served if I open http://localhost:8080/foo/index.html in a browser, but not if I open http://localhost:8080/foo or http://localhost:8080/foo/.

如果这是可能的，我如何设置我的 Akka HTTP 路由以默认在该位置提供 index.html 文件?

If this is even possible, how can I set up my Akka HTTP routes to serve index.html files within that location by default?

我知道我可以做到以下几点:

I know I could do the following:

val route: Route =
  path("foo") {
     getFromFile("foo/index.html")
  } ~
  pathPrefix("foo") {
    getFromDirectory("foo")
  }

但是:

• 这只会使 http://localhost:8080/foo 工作，而不是 http://localhost:8080/foo/
• 这是非常临时的，并不适用于全局:如果我有一个 foo/bar/index.html 文件，问题将是相同的.

• This only makes http://localhost:8080/foo work, not http://localhost:8080/foo/
• This is very ad-hoc and does not apply globally: if I have a foo/bar/index.html file, the problem will be the same.

推荐答案

您可以使用 pathEndOrSingleSlash 指令创建您正在寻找的 Route 指令:

You can create the Route you are looking for by using the pathEndOrSingleSlash Directive:

val route =
  pathPrefix("foo") {
    pathEndOrSingleSlash {
      getFromFile("foo/index.html")
    } ~ 
    getFromDirectory("foo")
  }

此路由将在路径的末尾匹配并提供 index.html，或者如果末尾不匹配，它将调用 getFromDirectory.

This Route will match at the end of the path and feed up the index.html, or if the end doesn't match it will call getFromDirectory instead.

如果你想让这个全局"，你可以用它创建一个函数:

If you want to make this "global" you can make a function out of it:

def routeAsDir[T](pathMatcher : PathMatcher[T], dir : String) : Route = 
  pathPrefix(pathMatcher) {
    pathEndOrSingleSlash {
      getFromFile(dir + "/index.html")
    } ~ 
    getFromDirectory(dir)
  }

然后可以使用

val barRoute = routeAsDir("foo" / "bar", "foo/bar")

函数式 Akka Http

旁注:您的代码完全正常运行.Directives DSL 的优雅可能会误导您，并让您相信您不小心误入了命令式编程风格.但每条指令都只是一个功能；没有比这更实用"的了...

Side note: your code is completely functional. The elegance of the Directives DSL can be a bit misleading and convince you that you've accidentally strayed back into imperative programming style. But each of the Directives is simply a function; can't get more "functional" than that...

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