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Setting environment variables in Scala JVM
import java.util.{Collections, Map => JavaMap}
import scala.collection.JavaConverters._
trait EnvHacker {
/**
* Portable method for setting env vars on both *nix and Windows.
* @see http://stackoverflow.com/a/7201825/293064
*/
def setEnv(newEnv: Map[String, String]): Unit = {
try {
val processEnvironmentClass = Class.forName("java.lang.ProcessEnvironment")
val theEnvironmentField = processEnvironmentClass.getDeclaredField("theEnvironment")
theEnvironmentField.setAccessible(true)
val env = theEnvironmentField.get(null).asInstanceOf[JavaMap[String, String]]
env.putAll(newEnv.asJava)
val theCaseInsensitiveEnvironmentField = processEnvironmentClass.getDeclaredField("theCaseInsensitiveEnvironment")
theCaseInsensitiveEnvironmentField.setAccessible(true)
val cienv = theCaseInsensitiveEnvironmentField.get(null).asInstanceOf[JavaMap[String, String]]
cienv.putAll(newEnv.asJava)
} catch {
case e: NoSuchFieldException =>
try {
val classes = classOf[Collections].getDeclaredClasses
val env = System.getenv()
for {cl <- classes} {
if (cl.getName == "java.util.Collections$UnmodifiableMap") {
val field = cl.getDeclaredField("m")
field.setAccessible(true)
val obj = field.get(env)
val map = obj.asInstanceOf[JavaMap[String, String]]
map.clear()
map.putAll(newEnv.asJava)
}
}
} catch {
case e2: Exception => e2.printStackTrace()
}
case e1: Exception => e1.printStackTrace()
}
}
}
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