RequestTask.kt

internal class RequestTask(private val req: Request) : Runnable {
        override fun run() {
            try {
                val conn = request()
                val parsedResponse = parseResponse(conn)
                req.sendResponse(parsedResponse, null)
            } catch (e: IOException) {
                req.sendResponse(null, e)
            }
        }

        @Throws(IOException::class)
        private fun request(): HttpURLConnection {
            val url = URL(req.url)
            val conn = url.openConnection() as HttpURLConnection
            val method = req.method
            conn.requestMethod = method
            for ((key, value) in req.header) {
                conn.setRequestProperty(key, value)
            }
            if (req.body != null) {
                val outputStream = conn.outputStream
                outputStream.write(req.body)
            }
            conn.connect()
            return conn
        }

        @Throws(IOException::class)
        private fun parseResponse(conn: HttpURLConnection): Response {
            try {
                val bos = ByteArrayOutputStream()
                val status = conn.responseCode
                val validStatus = status in 200..299
                val inpStream = if (validStatus) conn.inputStream else conn.errorStream
                var read: Int
                var totalRead = 0
                val buf = ByteArray(bufferSize)
                while (inpStream.read(buf).also { read = it } != -1) {
                    bos.write(buf, 0, read)
                    totalRead += read
                }
                return Response(bos.toByteArray())
            } finally {
                conn.disconnect()
            }
        }
    }