sbt - 如何避免激活器在访问“播放”页面时两次执行编译任务？

Question

我正在尝试在Play 2.3应用程序的编译之前运行自定义任务。我的build.sbt文件中有这个:

lazy val helloTask = TaskKey[Unit]("hello", "hello")

helloTask := {
  println("hello test")
}

(compile in Compile) <<= (compile in Compile) dependsOn helloTask

当我运行 activator ~run并在浏览器中打开一个页面时，得到以下输出:

C:\Development\test>activator ~run
[info] Loading project definition from C:\Development\test\project
[info] Set current project to play (in build file:/C:/Development/test/)

--- (Running the application from SBT, auto-reloading is enabled) ---

[info] play - Listening for HTTP on /0:0:0:0:0:0:0:0:9000

(Server started, use Ctrl+D to stop and go back to the console...)

hello test
[success] Compiled in 418ms
hello test
hello test
[info] play - Application started (Dev)

看来我的自定义任务正在运行3次。有办法避免这种情况吗？

Answer 1

我遇到了同样的问题，并且找到了解决方案。

在Sbt中，您有三个Scopes by configuration axis:

• Compile which defines the main build (src/main/scala).
• Test which defines how to build tests (src/test/scala).
• Runtime which defines the classpath for the run task.

您必须使用运行时而不是编译。它看起来应该像这样:

lazy val helloTask = taskKey[Unit]("hello")

helloTask := println("hello test")

(compile in Runtime) <<= (compile in Runtime) dependsOn helloTask