Scala: InputStream to Array[Byte]

Question

With Scala, what is the best way to read from an InputStream to a bytearray?

I can see that you can convert an InputStream to char array

Source.fromInput         


        

Answer 1

Just removed bottleneck in our server code by replacing

Stream.continually(request.getInputStream.read()).takeWhile(_ != -1).map(_.toByte).toArray

with

org.apache.commons.io.IOUtils.toByteArray(request.getInputStream)

Or in pure Scala:

def bytes(in: InputStream, initSize: Int = 8192): Array[Byte] = {
  var buf = new Array[Byte](initSize)
  val step = initSize
  var pos, n = 0
  while ({
    if (pos + step > buf.length) buf = util.Arrays.copyOf(buf, buf.length << 1)
    n = in.read(buf, pos, step)
    n != -1
  }) pos += n
  if (pos != buf.length) buf = util.Arrays.copyOf(buf, pos)
  buf
}

Do not forget to close an opened input stream in any case:

val in = request.getInputStream
try bytes(in) finally in.close()