Loan Pattern #scala

gistfile1.scala

import java.io._

object HexDumper {

  def main(args: Array[String]) {

    def withCloseable(args: Array[Closeable])(f: (Array[Closeable]) => Unit) =
      try f(args) finally args map { _.close }

    withCloseable(
      Array(
        new FileInputStream(new File(args(0))),
        new ByteArrayOutputStream())
    ) { args =>

      val is = args(0).asInstanceOf[FileInputStream]
      val os = args(1).asInstanceOf[ByteArrayOutputStream]

      var n = 0
      var buffer = new Array[Byte](4096)
      while ({ n = is.read(buffer, 0, 4096); n > 0 }) os.write(buffer, 0, n)

      os.toByteArray foreach { byte => print("%02X ".format(byte)) }
    }
  }
}