Scala example source code file (PluginProperties.scala)

This example Scala source code file (PluginProperties.scala) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Scala tags/keywords

none, none, option, option, pluginproperties, properties, some, some, string, string, util

The Scala PluginProperties.scala source code

package plugintemplate

import java.util.Properties

/** A utility to load properties of this plugin via the property
 *  file "plugin.properties"
 */
object PluginProperties {
  private val propFilename = "plugin.properties"

  val pluginName = getOrElse("plugin.name", "(name_unknown)")
  val pluginDescription = getOrElse("plugin.description", "(plugin description not found)")
  val pluginCommand = getOrElse("plugin.commandname", "(command_unknown)")
  val versionString = {
    val default = "(version_unknown)"
    props match {
      case Some(p) =>
        val major = p.getProperty("version.major")
        val minor = p.getProperty("version.minor")
        if ((major eq null) || (minor eq null)) default
        else major +"."+ minor
      case None => default
    }
  }

  private def getOrElse(property: String, default: String) = {
    props match {
      case Some(p) if (p.getProperty(property) != null) =>
        p.getProperty(property)
      case _ =>
        default
    }
  }

  private lazy val props: Option[Properties] = {
    /** Running from JAR file: the properties file should be in the
     *  jar as well
     */
    var stream = this.getClass.getResourceAsStream("/"+ propFilename)
    if (stream == null) {
      /** Running from .class files: expect classfiles to be in
       *  directory [...]/build/build.main, and [...] to contain
       *  the properties file.
       */
      try {
        val current = this.getClass.getClassLoader.getResource(".")
        val dir = new java.io.File(current.toURI)
        // dir will be [...]/build/build.main/
        stream = new java.io.FileInputStream(dir.getParentFile.getParent +"/"+ propFilename)
      } catch {
        case _ => ()
      }
    }
    if (stream == null) None
    else {
      val p = new Properties
      p.load(stream)
      Some(p)
    }
  }
}