Question

从playframework-2.2.4迁移到playframework-2.3.9后，我在运行时遇到以下错误：

[namek] $ run

java.util.NoSuchElementException: head of empty list
        at scala.collection.immutable.Nil$.head(List.scala:337)
        at scala.collection.immutable.Nil$.head(List.scala:334)
        at play.runsupport.Reloader$.startDevMode(Reloader.scala:184)
        at play.PlayRun$$anonfun$playRunTask$1$$anonfun$apply$2$$anonfun$apply$3.devModeServer$lzycompute$1(PlayRun.scala:75)
        at play.PlayRun$$anonfun$playRunTask$1$$anonfun$apply$2$$anonfun$apply$3.play$PlayRun$class$$anonfun$$anonfun$$anonfun$$devModeServer$1(PlayRun.scala:75)
        at play.PlayRun$$anonfun$playRunTask$1$$anonfun$apply$2$$anonfun$apply$3.apply(PlayRun.scala:98)
        at play.PlayRun$$anonfun$playRunTask$1$$anonfun$apply$2$$anonfun$apply$3.apply(PlayRun.scala:54)
        at scala.Function1$$anonfun$compose$1.apply(Function1.scala:47)
[trace] Stack trace suppressed: run last compile:run for the full output.
[error] (compile:run) java.util.NoSuchElementException: head of empty list
[error] Total time: 3 s, completed 26-May-2015 12:35:03

在源文件Reloader.scala：184（https://github.com/playframework/playframework/blob/2.3.9/framework/src/run-support/src/main/scala/play/runsupport/Reloader.scala）中，我看到对＆＃34; play-docs＆＃34;的引用在docsClasspath的名称中：Classpath作为startDevMode中的参数接收。

val docsJarFile = {
        val f = docsClasspath.filter(_.getName.startsWith("play-docs")).head
        new JarFile(f)
      }

我该怎么办？我无法找到关于此播放文档名称的任何参考。

UPDATE 似乎在旧版本中，playDocsJar使用了headOption而不是head（https://github.com/playframework/playframework/blob/848329be7d8a2d3d52d9031880332d46f845899e/framework/src/sbt-plugin/src/main/scala/play/sbt/PlaySettings.scala）

playDocsJar := (managedClasspath in DocsApplication).value.files.filter(_.getName.startsWith(playDocsName.value)).headOption,

Answer 1

作为解决方法，我创建了一个DocsApplication并添加了一个虚拟库

libraryDependencies += "com.typesafe.play" %% "play-docs" % play.core.PlayVersion.current % "docs"

Playframework迁移到2.3.9缺少播放文档并阻止startDevMode

1 个答案: