UploadImageToServerKotlinAsyncTask.kt

// pick single image from gallery

private fun openGalleryImages() {

        val intent = Intent(Intent.ACTION_PICK)
        intent.type = "image/*"
        startActivityForResult(Intent.createChooser(intent, "Select Picture"), TYPE_IMAGE)
    }

// get path
 private fun getPath(uri: Uri): String {
            val projection = arrayOf(MediaStore.Images.Media.DATA)
            val cursor = managedQuery(uri, projection, null, null, null)
            val column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA)
            cursor.moveToFirst()
            return cursor.getString(column_index)
        }

inner class UploadTask : AsyncTask<String, Int, Int>() {


        override fun doInBackground(vararg p0: String?): Int? = uploadFileToServer()

        private fun uploadFileToServer(): Int {
            val conn: HttpURLConnection?
            val dos: DataOutputStream?
            val lineEnd = "\r\n"
            val twoHyphens = "--"
            val boundary = "*****"
            var bytesRead: Int
            var bytesAvailable: Int
            var bufferSize: Int
            val buffer: ByteArray
            val maxBufferSize = 1 * 1024 * 1024
            var serverResponseCode = 0

            val sourceFile = File(getPath(mCurrentUri) )
            val fileName = getTimeString()

            if (!sourceFile.exists()) {
                runOnUiThread { Toast.makeText(this@EditProfileActivity, "File don't exists", Toast.LENGTH_SHORT).show() }

            } else {

                try {

                    // open a URL connection to the Servlet
                    val fileInputStream = FileInputStream(sourceFile)
                    val url = URL(UrlConstants.FILE_UPLOAD)

                    // Open a HTTP  connection to  the URL
                    conn = url.openConnection() as HttpURLConnection?
                    conn?.doInput = true // Allow Inputs
                    conn?.doOutput = true // Allow Outputs
                    conn?.useCaches = false // Don't use a Cached Copy
                    conn?.requestMethod = "POST"
                    conn?.setRequestProperty("Connection", "Keep-Alive")
                    conn?.setRequestProperty("ENCTYPE", "multipart/form-data")
                    conn?.setRequestProperty("Content-Type", "multipart/form-data;boundary=" + boundary)
                    conn?.setRequestProperty("uploaded_file", fileName)

                    dos = DataOutputStream(conn?.outputStream)

                    dos.writeBytes(twoHyphens + boundary + lineEnd)
                    dos.writeBytes("Content-Disposition: form-data; name=\"uploaded_file\";filename=\""
                            + fileName + "\"" + lineEnd)

                    dos.writeBytes(lineEnd)
                    // create a buffer of  maximum size
                    bytesAvailable = fileInputStream.available()
                    bufferSize = Math.min(bytesAvailable, maxBufferSize)
                    buffer = ByteArray(bufferSize)

                    // read file and write it into form...
                    bytesRead = fileInputStream.read(buffer, 0, bufferSize)

                    while (bytesRead > 0) {
                        dos.write(buffer, 0, bufferSize)
                        bytesAvailable = fileInputStream.available()
                        bufferSize = Math.min(bytesAvailable, maxBufferSize)
                        bytesRead = fileInputStream.read(buffer, 0, bufferSize)
                    }

                    // send multipart form data necesssary after file data...
                    dos.writeBytes(lineEnd)
                    dos.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd)

                    // Responses from the server (code and message)
                    serverResponseCode = conn!!.responseCode
                    val serverResponseMessage = conn.responseMessage

                    Log.i("uploadFile", "HTTP Response is : "
                            + serverResponseMessage + ": " + serverResponseCode)

                    if (serverResponseCode == 200) {
                        runOnUiThread({
                            run { Toast.makeText(this@EditProfileActivity, "200 ", Toast.LENGTH_SHORT).show() }
                        })
                    }

                    //close the streams //
                    fileInputStream.close()
                    dos.flush()
                    dos.close()

                } catch (ex: MalformedURLException) {

                    runOnUiThread({
                        run {
                            Toast.makeText(this@EditProfileActivity, "MalformedURLException", Toast.LENGTH_SHORT).show();
                        }
                    })

                    Log.e("Upload file to server", "error: " + ex.message, ex)
                } catch (e: Exception) {

                    e.printStackTrace()

                    runOnUiThread({
                        run {
                            Toast.makeText(this@EditProfileActivity, "Got Exception : see logcat ", Toast.LENGTH_SHORT).show();
                        }
                    })
                    Log.e("TAG", "Exception : " + e.message, e)
                }


            }
            return serverResponseCode

        }

        private fun getPath(uri: Uri): String {
            val projection = arrayOf(MediaStore.Images.Media.DATA)
            val cursor = managedQuery(uri, projection, null, null, null)
            val column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA)
            cursor.moveToFirst()
            return cursor.getString(column_index)
        }
        private fun getTimeString(): String {
            val timeStamp = SimpleDateFormat("yyyyMMdd_HHmmss").format(Date())
            return "JPEG_" + timeStamp + "_" + ".jpg"
        }
    }