InMemZip.scala

import java.util.zip._
import java.io._

class InMemZip(compressionLevel: Int) {
  private val _outBytes = new ByteArrayOutputStream
  private val _zipOutStream = {
    val s = new ZipOutputStream(_outBytes)
    s.setLevel(compressionLevel)
    s
  }

  private var _finished = false

  def finish(): Unit = {
    _zipOutStream.close
    _finished = true
  }

  def getBytes = {
    require(_finished, "Must call finish() first")
    _outBytes.toByteArray
  }

  def addEntry(filename: String, data: Array[Byte]): Unit = {
    val entry = new ZipEntry(filename)
    _zipOutStream.putNextEntry(entry)
    _zipOutStream.write(data, 0, data.length)
    _zipOutStream.closeEntry
  }

  def writeToFile(filename: String): File = {
    val file = new File(filename)
    val fos = new FileOutputStream(file)
    fos.write(getBytes)
    fos.close
    file
  }
}