.circumflex-core.2.3.source-code.circumflex.scala Maven / Gradle / Ivy

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package ru.circumflex
package core

import collection.mutable.{HashMap}
import java.util.{MissingResourceException, ResourceBundle, Locale}

/*!# Configuration API

This singleton can be used to retrieve Circumflex configuration parameters
throughout your application.

Configuration parameters are read from `cx.properties` which should be available
in classpath.

You can also configure your application in runtime, just add your configuration
parameters into `Circumflex` using methods of Scala's `Map` interface.
Note, however, that `Circumflex` singleton is not thread-safe, so it is a best
practice to only set configuration parameters inside some initialization block
which will be executed only once by only one thread.

[Circumflex Maven Plugin](http://circumflex.ru/projects/maven-plugin/index.html)
enables you to configure your application at build time using Maven properties
(specified either in application's `pom.xml` or in `settings.xml`) and system
properties (specified in command line). This is very robust production scenario,
because it allows different configurations in different environments without
manual filtering sources and resources.
*/
object Circumflex extends HashMap[String, Any] with KeyValueCoercion {

  def locateBundle: Option[ResourceBundle] = try {
    Some(ResourceBundle.getBundle("cx"))
  } catch {
    case e: MissingResourceException =>
      CX_LOG.error("cx.properties not found in classpath. " +
          "Starting with empty configuration.")
      None
  }

  // The configuration object is initialized by reading `cx.properties`.
  try {
    locateBundle.map { bundle =>
      val keys = bundle.getKeys
      while (keys.hasMoreElements) {
        val k = keys.nextElement
        this(k) = bundle.getString(k)
      }
    }
  } catch {
    case e: Exception =>
      CX_LOG.error("Could not read configuration parameters from cx.properties.", e)
  }

  override def stringPrefix = "cx"
}