How to load setting values from a Java properties file?

问题

Is there a way for me to dynamically load a setting value from a properties file?

I mean, instead of hardcoding into build.sbt

name := "helloWorld"

Have some application.properties file with

name=helloWorld

And then, in the build.sbt file, have name := application.properties["name"] (last example is purely schematic, but I hope the idea was clear)

回答1:

You can create a setting key which holds properties read from a file.

import java.util.Properties

val appProperties = settingKey[Properties]("The application properties")

appProperties := {
  val prop = new Properties()
  IO.load(prop, new File("application.properties"))
  prop
}

name := appProperties.value.getProperty("name")

回答2:

Cheating a bit on the answer from @daniel-olszewski.

In project/build.sbt declare dependency on Typesafe Config:

libraryDependencies += "com.typesafe" % "config" % "1.2.1"

In build.sbt load properties using Typesafe Config and set settings:

import com.typesafe.config.{ConfigFactory, Config}

lazy val appProperties = settingKey[Config]("The application properties")

appProperties := {
  ConfigFactory.load()
}

name := {
  try {
    appProperties.value.getString("name")
  } catch {
    case _: Exception => "<empty>"
  }
}

You could define a def that would set values from the properties, too.

来源：https://stackoverflow.com/questions/25665848/how-to-load-setting-values-from-a-java-properties-file