Dart

Download a Binary File into Memory

See more Azure Cloud Storage Examples

Downloads a binary file into memory. Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // Azure File Service Example: Download a Binary File to Memory
  // See:  https://docs.microsoft.com/en-us/rest/api/storageservices/get-file

  // This example requires the Chilkat API to have been previously unlocked.
  // See Global Unlock Sample for sample code.

  final rest = CkRest();

  // Connect to the Azure Storage Blob Service
  final bTls = true;
  final port = 443;
  final bAutoReconnect = true;
  // In this example, the storage account name is "chilkat".
  try {
    rest.connect('chilkat.file.core.windows.net', port, bTls, bAutoReconnect);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Provide Azure Cloud credentials for the REST calls.
  final azAuth = CkAuthAzureStorage();
  azAuth.accessKey = 'AZURE_ACCESS_KEY';
  // The account name used here should match the 1st part of the domain passed in the call to Connect (above).
  azAuth.account = 'chilkat';
  azAuth.scheme = 'SharedKey';
  azAuth.service = 'File';
  // This causes the "x-ms-version: 2021-08-06" header to be automatically added.
  azAuth.xMsVersion = '2021-08-06';
  rest.setAuthAzureStorage(azAuth);

  // Note: The application does not need to explicitly set the following
  // headers: x-ms-date, Authorization.  These headers
  // are automatically set by Chilkat.

  // Send a GET request to download the file "penguins.jpg" to a BinData object.
  // (The share name is "pip")
  final bdFileContents = CkBinData();
  try {
    rest.fullRequestNoBodyBd('GET', '/pip/wildlife/antarctic/penguins.jpg', bdFileContents);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // When successful, the response status will be 200.
  // If a non-success status code is returned, then the bdFileContents actually contains the XML error message.
  if (rest.responseStatusCode != 200) {
    // Examine the request/response to see what happened.
    print('response status code = ${rest.responseStatusCode}');
    print('response status text = ${rest.responseStatusText}');
    print('response header: ${rest.responseHeader}');
    final sbXmlErr = CkStringBuilder();
    sbXmlErr.appendBd(bdFileContents, 'utf-8', 0, 0);
    print('response body (if any): ${sbXmlErr.getAsString()}');
    print('---');
    print('LastRequestStartLine: ${rest.lastRequestStartLine}');
    print('LastRequestHeader: ${rest.lastRequestHeader}');
    return;
  }

  print('Size of the downloaded file = ${bdFileContents.numBytes}');

  // See the online reference documentation for the BinData class for ways
  // to access the bytes.

  bdFileContents.writeFile('qa_output/penguins.jpg');
}