React Native

(using AWS Signature Version 2) Streaming Download to File

See more Amazon S3 (new) Examples

The main purpose of this example is to demonstrate how to use the older Signature Version 2 authentication w/ S3. It uses V2 authentication to download a file. React Native

import { AuthAws, Rest, Stream } from '@chilkat/react-native'

async function chilkatExample() {
  // This example requires the Chilkat API to have been previously unlocked.
  // See Global Unlock Sample for sample code.

  const rest = new Rest();

  // Connect to the Amazon AWS REST server.
  const bTls = true;
  const port = 443;
  const bAutoReconnect = true;
  // The file is located in the bucket named "chilkat100", which becomes part of the domain:
  await rest.connectAsync('chilkat100.s3.amazonaws.com', port, bTls, bAutoReconnect);

  // Provide AWS credentials for the REST call.
  const authAws = new AuthAws();
  authAws.accessKey = 'AWS_ACCESS_KEY';
  authAws.secretKey = 'AWS_SECRET_KEY';
  authAws.serviceName = 's3';

  // For AWS Signature Version 2, the following two properties need to be set:
  authAws.signatureVersion = 2;
  // See http://docs.aws.amazon.com/AmazonS3/latest/dev/RESTAuthentication.html#ConstructingTheCanonicalizedResourceElement
  authAws.canonicalizedResourceV2 = '/chilkat100/starfish.jpg';

  rest.setAuthAws(authAws);

  // Send the request to download the JPG.
  try {
    await rest.sendReqNoBodyAsync('GET', '/starfish.jpg');
  } catch {
    console.log(rest.lastErrorText);
    return;
  }

  // Read the response header.
  const responseStatusCode = await rest.readResponseHeaderAsync();
  if (responseStatusCode < 0) {
    console.log(rest.lastErrorText);
    return;
  }

  console.log(`Response status code = ${responseStatusCode}`);

  // We expect a 200 response status if the JPG data is coming.
  // Otherwise, we'll get a string response body with an error message(or no response body).
  if (responseStatusCode === 200) {

    const bodyStream = new Stream();

    // The stream's sink will be a file.
    bodyStream.sinkFile = 'qa_output/starfish.jpg';

    // Read the response body to the stream.  Given that we've
    // set the stream's sink to a file, it will stream directly
    // to the file.
    try {
      await rest.readRespBodyStreamAsync(bodyStream, true);
    } catch {
      console.log(rest.lastErrorText);
      return;
    }

    console.log('Successfully received the JPG file.');
  } else {
    try {
      const errResponse = await rest.readRespBodyStringAsync();
      console.log(errResponse);
    } catch {
      console.log(rest.lastErrorText);
    }
  }
}