CharsetSupportedControl.scala

import java.io._
import java.util._
import java.util.ResourceBundle.Control
import java.net._
import java.security._

class CharsetSupportedControl(charset: String = "utf-8") extends Control {
  override def newBundle(baseName: String, locale: Locale, format: String, loader: ClassLoader, reload: Boolean) : ResourceBundle= {
    if ("java.class" == format) {
      super.newBundle(baseName, locale, format, loader, reload)
    } else if ("java.properties" == format) {
      val bundleName = toBundleName(baseName, locale)
      val resourceName = toResourceName(bundleName, "properties")
      val stream = getStream(resourceName, loader, reload)
      if (stream != null) {
        try {
          val br = new BufferedReader(new InputStreamReader(stream, charset))
          try {
            return new PropertyResourceBundle(br)
          } finally {
            br.close()
          }
        } finally {
          stream.close()
        }
      }

      null
    } else {
      throw new IllegalArgumentException("unknown format: " + format)
    }
  }

  def getStream(resourceName: String, loader: ClassLoader, reload: Boolean) : InputStream = {
    try {
      AccessController.doPrivileged(
        new PrivilegedExceptionAction[InputStream]() {
          override def run() : InputStream = {
            if (reload) {
              val url = loader.getResource(resourceName)
              if (url != null) {
                val connection = url.openConnection()
                if (connection != null) {
                  connection.setUseCaches(false)
                  return connection.getInputStream()
                }
              }
            } else {
              return loader.getResourceAsStream(resourceName)
            }

            return null
          }
        })
    } catch {
      case e: PrivilegedActionException => throw e.getException()
    }
  }
}

object Main extends Application {
  // message.properties をクラスパス直下に
  val bundle = ResourceBundle.getBundle("messages", new CharsetSupportedControl())
  println(bundle.getString("message"))
}