Refactored a pile of duplicated Properties code...

Refactored a pile of duplicated Properties code into a trait which is
used by the library, compiler, and partest Properties objects.

3 files changed, 67 insertions, 140 deletions

diff --git a/src/compiler/scala/tools/nsc/Properties.scala b/src/compiler/scala/tools/nsc/Properties.scala
index fcc522df93..4ec98a1d0c 100644
--- a/src/compiler/scala/tools/nsc/Properties.scala
+++ b/src/compiler/scala/tools/nsc/Properties.scala
@@ -6,68 +6,24 @@
 // $Id$
 
 package scala.tools.nsc
+import scala.util.PropertiesTrait
 
 /** A utility to load the compiler properties from a Java properties file
  *  included in the jar.
  */
-object Properties {
-
-  /** The name of the properties file */
-  private val propFilename = "/compiler.properties"
-
-  /** The loaded properties */
-  private val props = {
-    val props = new java.util.Properties
-    val stream = classOf[Global].getResourceAsStream(propFilename)
-    if (stream != null)
-      props.load(stream)
-    props
-  }
-
-  val isWin = System.getProperty("os.name") startsWith "Windows"
-
-  /** The version number of the jar this was loaded from, or
-    * "(unknown)" if it cannot be determined.
-    */
-  val versionString: String = {
-    val defaultString = "(unknown)"
-    "version " + props.getProperty("version.number", defaultString)
-  }
-
-  val copyrightString: String = {
-    val defaultString = "(c) 2002-2009 LAMP/EPFL"
-    props.getProperty("copyright.string", defaultString)
-  }
-
-  val encodingString: String = {
-    val defaultString = "UTF8" //"ISO-8859-1"
-    props.getProperty("file.encoding", defaultString)
-  }
-
-  val fileEndingString: String = {
-    val defaultString = ".scala|.java"
-    props.getProperty("file.ending", defaultString)
-  }
-
-  val residentPromptString: String = {
-    val defaultString = "\nnsc> "
-    props.getProperty("resident.prompt", defaultString)
-  }
-
-  val shellPromptString: String = {
-    val defaultString = "\nscala> "
-    props.getProperty("shell.prompt", defaultString)
-  }
-
-  val scalaHome: String =
-    System.getProperty("scala.home")
-
-  val envClasspath: String =
-    System.getProperty("env.classpath")
-
-  val cmdName: String =
-    if (isWin) "scala.bat" else "scala"
-
-  val msilILasm: String =
-    System.getProperty("msil.ilasm", "")
+object Properties extends PropertiesTrait {
+  protected def propCategory    = "compiler"
+  protected def pickJarBasedOn  = classOf[Global]
+
+  // settings based on jar properties
+  val fileEndingString      = prop("file.ending", ".scala|.java")
+  val residentPromptString  = prop("resident.prompt", "\nnsc> ")
+  val shellPromptString     = prop("shell.prompt", "\nscala> ")
+
+  // settings based on System properties
+  val isWin                 = sysprop("os.name", "") startsWith "Windows"
+  val scalaHome             = sysprop("scala.home", null)
+  val envClasspath          = sysprop("env.classpath", null)
+  val msilILasm             = sysprop("msil.ilasm", "")
+  val cmdName               = if (isWin) "scala.bat" else "scala"
 }
diff --git a/src/library/scala/util/Properties.scala b/src/library/scala/util/Properties.scala
index 358e635742..77a2a10c4c 100644
--- a/src/library/scala/util/Properties.scala
+++ b/src/library/scala/util/Properties.scala
@@ -11,59 +11,62 @@
 
 package scala.util
 
-/** A utility to load the library properties from a Java properties file
- *  included in the jar.
- *
- *  @author Stephane Micheloud
- */
-object Properties {
+private[scala] trait PropertiesTrait
+{
+  import java.io.{ IOException, PrintWriter }
+  protected def propCategory: String      // specializes the remainder of the values
+  protected def pickJarBasedOn: Class[_]  // props file comes from jar containing this
 
   /** The name of the properties file */
-  private val propFilename = "/library.properties"
+  protected val propFilename = "/" + propCategory + ".properties"
 
   /** The loaded properties */
-  private val props = {
+  protected lazy val props: java.util.Properties = {
     val props = new java.util.Properties
-    val stream = classOf[Application].getResourceAsStream(propFilename)
-    try {
-      if (stream != null)
-        props.load(stream)
-    } finally {
-      if (stream != null) {
-        // close quietly
-        try {
-          stream.close()
-        } catch {
-          case _ =>
-        }
-      }
-    }
+    val stream = pickJarBasedOn getResourceAsStream propFilename
+    if (stream ne null)
+      quietlyDispose(props load stream, stream.close)
+
     props
   }
 
-  /** The version number of the jar this was loaded from plus "version " prefix,
-   * or "version (unknown)" if it cannot be determined.
-   */
-  val versionString: String = {
-    val defaultString = "(unknown)"
-    "version " + props.getProperty("version.number", defaultString)
-  }
+  private def quietlyDispose(action: => Unit, disposal: => Unit) =
+    try     { action }
+    finally {
+        try     { disposal }
+        catch   { case _: IOException => }
+    }
 
-  val copyrightString: String = {
-    val defaultString = "(c) 2002-2009 LAMP/EPFL"
-    props.getProperty("copyright.string", defaultString)
-  }
+  // for values based on system properties
+  protected def sysprop(name: String, default: String) =
+    System.getProperty(name, default)
 
-  val encodingString: String = {
-    val defaultString = "UTF8" //"ISO-8859-1"
-    props.getProperty("file.encoding", defaultString)
-  }
+  // for values based on propFilename
+  protected def prop(name: String, default: String): String =
+    props.getProperty(name, default)
 
-  private val writer = new java.io.PrintWriter(Console.err, true)
+  // XXX file.encoding should not be here, as it causes system setting to
+  // be ignored.  See https://lampsvn.epfl.ch/trac/scala/ticket/1581
 
-  val versionMsg = "Scala library " + versionString + " -- " + copyrightString
+  /** The version number of the jar this was loaded from plus "version " prefix,
+   *  or "version (unknown)" if it cannot be determined.
+   */
+  val versionString         = "version " + prop("version.number", "(unknown)")
+  val copyrightString       = prop("copyright.string", "(c) 2002-2009 LAMP/EPFL")
+  val encodingString        = prop("file.encoding", "UTF8")
 
-  def main(args: Array[String]) {
-    writer.println(versionMsg)
-  }
+  // provide a main method so version info can be obtained by running this
+  private val writer = new java.io.PrintWriter(Console.err, true)
+  private val versionMsg = "Scala %s %s -- %s".format(propCategory, versionString, copyrightString)
+  def main(args: Array[String]) { writer println versionMsg }
+}
+
+/** A utility to load the library properties from a Java properties file
+ *  included in the jar.
+ *
+ *  @author Stephane Micheloud
+ */
+object Properties extends PropertiesTrait {
+  protected def propCategory    = "library"
+  protected def pickJarBasedOn  = classOf[Application]
 }
diff --git a/src/partest/scala/tools/partest/utils/Properties.scala b/src/partest/scala/tools/partest/utils/Properties.scala
index 76d333eccb..1807c26cf2 100644
--- a/src/partest/scala/tools/partest/utils/Properties.scala
+++ b/src/partest/scala/tools/partest/utils/Properties.scala
@@ -9,49 +9,17 @@
 // $Id$
 
 package scala.tools.partest.utils
+import scala.util.PropertiesTrait
 
 /** A utility to load the library properties from a Java properties file
  *  included in the jar.
  *
  *  @author Stephane Micheloud
  */
-object Properties {
+object Properties extends PropertiesTrait {
+  protected def propCategory    = "partest"
+  protected def pickJarBasedOn  = classOf[Application]
 
-  /** The name of the properties file */
-  private val propFilename = "/partest.properties"
-
-  /** The loaded properties */
-  private val props = {
-    val props = new java.util.Properties
-    val stream = classOf[Application].getResourceAsStream(propFilename)
-    if (stream != null)
-      props.load(stream)
-    props
-  }
-
-  /** The version number of the jar this was loaded from, or
-    * "(unknown)" if it cannot be determined.
-    */
-  val versionString: String = {
-    val defaultString = "(unknown)"
-    "version " + props.getProperty("version.number")
-  }
-
-  val copyrightString: String = {
-    val defaultString = "(c) 2002-2009 LAMP/EPFL"
-    props.getProperty("copyright.string", defaultString)
-  }
-
-  val encodingString: String = {
-    val defaultString = "ISO-8859-1"
-    props.getProperty("file.encoding", defaultString)
-  }
-
-  private val writer = new java.io.PrintWriter(Console.err, true)
-
-  val versionMsg = "Scala partest " + versionString + " -- " + copyrightString
-
-  def main(args: Array[String]) {
-    writer.println(versionMsg)
-  }
+  // XXX unlikely it's intentional that only partest uses ISO-8859-1
+  override val encodingString = prop("file.encoding", "ISO-8859-1")
 }