Scala example source code file (File.scala)

This example Scala source code file (File.scala) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Scala source code examples by using tags.

All credit for the original source code belongs to scala-lang.org; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Scala tags/keywords

boolean, bufferedwriter, codec, file, io, jfile, outputstreamwriter, path, printwriter, string, unit

The File.scala Scala example source code

/*                     __                                               *\
**     ________ ___   / /  ___     Scala API                            **
**    / __/ __// _ | / /  / _ |    (c) 2003-2013, LAMP/EPFL             **
**  __\ \/ /__/ __ |/ /__/ __ |    http://scala-lang.org/               **
** /____/\___/_/ |_/____/_/ | |                                         **
**                          |/                                          **
\*                                                                      */


package scala
package reflect
package io

import java.io.{
  FileInputStream, FileOutputStream, BufferedReader, BufferedWriter, InputStreamReader, OutputStreamWriter,
  BufferedInputStream, BufferedOutputStream, IOException, PrintStream, PrintWriter, Closeable => JCloseable,
  File => JFile
}

import java.nio.channels.{ Channel, FileChannel }
import scala.io.Codec
import scala.language.{reflectiveCalls, implicitConversions}
/**
 * ''Note:  This library is considered experimental and should not be used unless you know what you are doing.''
 */
object File {
  def pathSeparator = java.io.File.pathSeparator
  def separator     = java.io.File.separator
  def apply(path: Path)(implicit codec: Codec) = new File(path.jfile)(codec)

  // Create a temporary file, which will be deleted upon jvm exit.
  def makeTemp(prefix: String = Path.randomPrefix, suffix: String = null, dir: JFile = null) = {
    val jfile = java.io.File.createTempFile(prefix, suffix, dir)
    jfile.deleteOnExit()
    apply(jfile)
  }
}

/** An abstraction for files.  For character data, a Codec
 *  can be supplied at either creation time or when a method
 *  involving character data is called (with the latter taking
 *  precedence if supplied.) If neither is available, the value
 *  of scala.io.Codec.default is used.
 *
 *  @author  Paul Phillips
 *  @since   2.8
 *
 *  ''Note:  This is library is considered experimental and should not be used unless you know what you are doing.''
 */
class File(jfile: JFile)(implicit constructorCodec: Codec) extends Path(jfile) with Streamable.Chars {
  override val creationCodec = constructorCodec

  override def addExtension(ext: String): File = super.addExtension(ext).toFile
  override def toAbsolute: File = if (isAbsolute) this else super.toAbsolute.toFile
  override def toDirectory: Directory = new Directory(jfile)
  override def toFile: File = this
  override def normalize: File = super.normalize.toFile
  override def length = super[Path].length
  override def walkFilter(cond: Path => Boolean): Iterator[Path] =
    if (cond(this)) Iterator.single(this) else Iterator.empty

  /** Obtains an InputStream. */
  def inputStream() = new FileInputStream(jfile)

  /** Obtains a OutputStream. */
  def outputStream(append: Boolean = false) = new FileOutputStream(jfile, append)
  def bufferedOutput(append: Boolean = false) = new BufferedOutputStream(outputStream(append))

  /** Obtains an OutputStreamWriter wrapped around a FileOutputStream.
   *  This should behave like a less broken version of java.io.FileWriter,
   *  in that unlike the java version you can specify the encoding.
   */
  def writer(append: Boolean, codec: Codec): OutputStreamWriter =
    new OutputStreamWriter(outputStream(append), codec.charSet)

  /** Wraps a BufferedWriter around the result of writer().
   */
  def bufferedWriter(): BufferedWriter = bufferedWriter(append = false)
  def bufferedWriter(append: Boolean): BufferedWriter = bufferedWriter(append, creationCodec)
  def bufferedWriter(append: Boolean, codec: Codec): BufferedWriter =
    new BufferedWriter(writer(append, codec))

  def printWriter(): PrintWriter = new PrintWriter(bufferedWriter(), true)

  /** Creates a new file and writes all the Strings to it. */
  def writeAll(strings: String*): Unit = {
    val out = bufferedWriter()
    try strings foreach (out write _)
    finally out.close()
  }

  def appendAll(strings: String*): Unit = {
    val out = bufferedWriter(append = true)
    try strings foreach (out write _)
    finally out.close()
  }

  /** Calls println on each string (so it adds a newline in the PrintWriter fashion.) */
  def printlnAll(strings: String*): Unit = {
    val out = printWriter()
    try strings foreach (out println _)
    finally out.close()
  }

  def safeSlurp(): Option[String] =
    try Some(slurp())
    catch { case _: IOException => None }

  /** Reflection since we're into the java 6+ API.
   */
  def setExecutable(executable: Boolean, ownerOnly: Boolean = true): Boolean = {
    type JBoolean = java.lang.Boolean
    val method =
      try classOf[JFile].getMethod("setExecutable", classOf[Boolean], classOf[Boolean])
      catch { case _: NoSuchMethodException => return false }

    try method.invoke(jfile, executable: JBoolean, ownerOnly: JBoolean).asInstanceOf[JBoolean].booleanValue
    catch { case _: Exception => false }
  }
}