Scala example source code file (ZipArchive.scala)

This example Scala source code file (ZipArchive.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

annotation, any, boolean, collection, direntry, entry, fileentry, fileziparchive, ioexception, iterator, string, ziparchive

The ZipArchive.scala Scala example source code

/* NSC -- new Scala compiler
 * Copyright 2005-2013 LAMP/EPFL
 * @author  Paul Phillips
 */

package scala
package reflect
package io

import java.net.URL
import java.io.{ IOException, InputStream, ByteArrayInputStream, FilterInputStream }
import java.io.{ File => JFile }
import java.util.zip.{ ZipEntry, ZipFile, ZipInputStream }
import java.util.jar.Manifest
import scala.collection.{ immutable, mutable }
import scala.collection.convert.WrapAsScala.asScalaIterator
import scala.annotation.tailrec

/** An abstraction for zip files and streams.  Everything is written the way
 *  it is for performance: we come through here a lot on every run.  Be careful
 *  about changing it.
 *
 *  @author  Philippe Altherr (original version)
 *  @author  Paul Phillips (this one)
 *  @version 2.0,
 *
 *  ''Note:  This library is considered experimental and should not be used unless you know what you are doing.''
 */
object ZipArchive {
  /**
   * @param   file  a File
   * @return  A ZipArchive if `file` is a readable zip file, otherwise null.
   */
  def fromFile(file: File): FileZipArchive = fromFile(file.jfile)
  def fromFile(file: JFile): FileZipArchive =
    try   { new FileZipArchive(file) }
    catch { case _: IOException => null }

  /**
   * @param   url  the url of a zip file
   * @return  A ZipArchive backed by the given url.
   */
  def fromURL(url: URL): URLZipArchive = new URLZipArchive(url)

  def fromManifestURL(url: URL): AbstractFile = new ManifestResources(url)

  private def dirName(path: String)  = splitPath(path, front = true)
  private def baseName(path: String) = splitPath(path, front = false)
  private def splitPath(path0: String, front: Boolean): String = {
    val isDir = path0.charAt(path0.length - 1) == '/'
    val path  = if (isDir) path0.substring(0, path0.length - 1) else path0
    val idx   = path.lastIndexOf('/')

    if (idx < 0)
      if (front) "/"
      else path
    else
      if (front) path.substring(0, idx + 1)
      else path.substring(idx + 1)
  }
}
import ZipArchive._
/** ''Note:  This library is considered experimental and should not be used unless you know what you are doing.'' */
abstract class ZipArchive(override val file: JFile) extends AbstractFile with Equals {
  self =>

  override def underlyingSource = Some(this)
  def isDirectory = true
  def lookupName(name: String, directory: Boolean) = unsupported()
  def lookupNameUnchecked(name: String, directory: Boolean) = unsupported()
  def create()  = unsupported()
  def delete()  = unsupported()
  def output    = unsupported()
  def container = unsupported()
  def absolute  = unsupported()

  private def walkIterator(its: Iterator[AbstractFile]): Iterator[AbstractFile] = {
    its flatMap { f =>
      if (f.isDirectory) walkIterator(f.iterator)
      else Iterator(f)
    }
  }
  /** ''Note:  This library is considered experimental and should not be used unless you know what you are doing.'' */
  sealed abstract class Entry(path: String) extends VirtualFile(baseName(path), path) {
    // have to keep this name for compat with sbt's compiler-interface
    def getArchive: ZipFile = null
    override def underlyingSource = Some(self)
    override def toString = self.path + "(" + path + ")"
  }
  /** ''Note:  This library is considered experimental and should not be used unless you know what you are doing.'' */
  class DirEntry(path: String) extends Entry(path) {
    val entries = mutable.HashMap[String, Entry]()

    override def isDirectory = true
    override def iterator: Iterator[Entry] = entries.valuesIterator
    override def lookupName(name: String, directory: Boolean): Entry = {
      if (directory) entries(name + "/")
      else entries(name)
    }
  }

  private def ensureDir(dirs: mutable.Map[String, DirEntry], path: String, zipEntry: ZipEntry): DirEntry =
    //OPT inlined from getOrElseUpdate; saves ~50K closures on test run.
    // was:
    // dirs.getOrElseUpdate(path, {
    //   val parent = ensureDir(dirs, dirName(path), null)
    //   val dir    = new DirEntry(path)
    //   parent.entries(baseName(path)) = dir
    //   dir
    // })
    dirs get path match {
      case Some(v) => v
      case None =>
        val parent = ensureDir(dirs, dirName(path), null)
        val dir    = new DirEntry(path)
        parent.entries(baseName(path)) = dir
        dirs(path) = dir
        dir
    }

  protected def getDir(dirs: mutable.Map[String, DirEntry], entry: ZipEntry): DirEntry = {
    if (entry.isDirectory) ensureDir(dirs, entry.getName, entry)
    else ensureDir(dirs, dirName(entry.getName), null)
  }
}
/** ''Note:  This library is considered experimental and should not be used unless you know what you are doing.'' */
final class FileZipArchive(file: JFile) extends ZipArchive(file) {
  def iterator: Iterator[Entry] = {
    val zipFile = try {
      new ZipFile(file)
    } catch {
      case ioe: IOException => throw new IOException("Error accessing " + file.getPath, ioe)
    }
    val root    = new DirEntry("/")
    val dirs    = mutable.HashMap[String, DirEntry]("/" -> root)
    val enum    = zipFile.entries()

    while (enum.hasMoreElements) {
      val zipEntry = enum.nextElement
      val dir = getDir(dirs, zipEntry)
      if (zipEntry.isDirectory) dir
      else {
        class FileEntry() extends Entry(zipEntry.getName) {
          override def getArchive   = zipFile
          override def lastModified = zipEntry.getTime()
          override def input        = getArchive getInputStream zipEntry
          override def sizeOption   = Some(zipEntry.getSize().toInt)
        }
        val f = new FileEntry()
        dir.entries(f.name) = f
      }
    }

    try root.iterator
    finally dirs.clear()
  }

  def name         = file.getName
  def path         = file.getPath
  def input        = File(file).inputStream()
  def lastModified = file.lastModified

  override def sizeOption = Some(file.length.toInt)
  override def canEqual(other: Any) = other.isInstanceOf[FileZipArchive]
  override def hashCode() = file.hashCode
  override def equals(that: Any) = that match {
    case x: FileZipArchive => file.getAbsoluteFile == x.file.getAbsoluteFile
    case _                 => false
  }
}
/** ''Note:  This library is considered experimental and should not be used unless you know what you are doing.'' */
final class URLZipArchive(val url: URL) extends ZipArchive(null) {
  def iterator: Iterator[Entry] = {
    val root     = new DirEntry("/")
    val dirs     = mutable.HashMap[String, DirEntry]("/" -> root)
    val in       = new ZipInputStream(new ByteArrayInputStream(Streamable.bytes(input)))

    @tailrec def loop() {
      val zipEntry = in.getNextEntry()
      class EmptyFileEntry() extends Entry(zipEntry.getName) {
        override def toByteArray: Array[Byte] = null
        override def sizeOption = Some(0)
      }
      class FileEntry() extends Entry(zipEntry.getName) {
        override val toByteArray: Array[Byte] = {
          val len    = zipEntry.getSize().toInt
          val arr    = if (len == 0) Array.emptyByteArray else new Array[Byte](len)
          var offset = 0

          def loop() {
            if (offset < len) {
              val read = in.read(arr, offset, len - offset)
              if (read >= 0) {
                offset += read
                loop()
              }
            }
          }
          loop()

          if (offset == arr.length) arr
          else throw new IOException("Input stream truncated: read %d of %d bytes".format(offset, len))
        }
        override def sizeOption = Some(zipEntry.getSize().toInt)
      }

      if (zipEntry != null) {
        val dir = getDir(dirs, zipEntry)
        if (zipEntry.isDirectory)
          dir
        else {
          val f = if (zipEntry.getSize() == 0) new EmptyFileEntry() else new FileEntry()
          dir.entries(f.name) = f
        }
        in.closeEntry()
        loop()
      }
    }

    loop()
    try root.iterator
    finally dirs.clear()
  }

  def name  = url.getFile()
  def path  = url.getPath()
  def input = url.openStream()
  def lastModified =
    try url.openConnection().getLastModified()
    catch { case _: IOException => 0 }

  override def canEqual(other: Any) = other.isInstanceOf[URLZipArchive]
  override def hashCode() = url.hashCode
  override def equals(that: Any) = that match {
    case x: URLZipArchive => url == x.url
    case _                => false
  }
}

final class ManifestResources(val url: URL) extends ZipArchive(null) {
  def iterator = {
    val root     = new DirEntry("/")
    val dirs     = mutable.HashMap[String, DirEntry]("/" -> root)
    val manifest = new Manifest(input)
    val iter     = manifest.getEntries().keySet().iterator().filter(_.endsWith(".class")).map(new ZipEntry(_))

    while (iter.hasNext) {
      val zipEntry = iter.next()
      val dir = getDir(dirs, zipEntry)
      if (zipEntry.isDirectory) dir
      else {
        class FileEntry() extends Entry(zipEntry.getName) {
          override def lastModified = zipEntry.getTime()
          override def input        = resourceInputStream(path)
          override def sizeOption   = None
        }
        val f = new FileEntry()
        dir.entries(f.name) = f
      }
    }

    try root.iterator
    finally dirs.clear()
  }

  def name  = path
  def path: String = {
    val s = url.getPath
    val n = s.lastIndexOf('!')
    s.substring(0, n)
  }
  def input = url.openStream()
  def lastModified =
    try url.openConnection().getLastModified()
    catch { case _: IOException => 0 }

  override def canEqual(other: Any) = other.isInstanceOf[ManifestResources]
  override def hashCode() = url.hashCode
  override def equals(that: Any) = that match {
    case x: ManifestResources => url == x.url
    case _                => false
  }

  private def resourceInputStream(path: String): InputStream = {
    new FilterInputStream(null) {
      override def read(): Int = {
        if(in == null) in = Thread.currentThread().getContextClassLoader().getResourceAsStream(path);
        if(in == null) throw new RuntimeException(path + " not found")
        super.read();
      }

      override def close(): Unit = {
        super.close();
        in = null;
      }
    }
  }
}