(Android™) REST Read Response with Stream API

Demonstrates how to make a REST call that returns a binary body, and to receive the body through a stream API.

Chilkat Android™ Downloads Android™ Java Libraries Android C/C++ Libraries

// Important: Don't forget to include the call to System.loadLibrary
// as shown at the bottom of this code sample.
package com.test;

import android.app.Activity;
import com.chilkatsoft.*;

import android.widget.TextView;
import android.os.Bundle;

public class SimpleActivity extends Activity {

  private static final String TAG = "Chilkat";

  // Called when the activity is first created.
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

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

    CkRest rest = new CkRest();

    // Connect to the Amazon AWS REST server.
    boolean bTls = true;
    int port = 443;
    boolean bAutoReconnect = true;
    boolean success = rest.Connect("s3.amazonaws.com",port,bTls,bAutoReconnect);

    // ----------------------------------------------------------------------------
    // Important: For buckets created in regions outside us-east-1,
    // there are three important changes that need to be made.
    // See Working with S3 Buckets in Non-us-east-1 Regions for the details.
    // ----------------------------------------------------------------------------

    // Provide AWS credentials for the REST call.
    CkAuthAws authAws = new CkAuthAws();
    authAws.put_AccessKey("AWS_ACCESS_KEY");
    authAws.put_SecretKey("AWS_SECRET_KEY");
    authAws.put_ServiceName("s3");
    success = rest.SetAuthAws(authAws);

    // Set the bucket name via the HOST header.
    // In this case, the bucket name is "chilkat100".
    rest.put_Host("chilkat100.s3.amazonaws.com");

    // Send the request to download the JPG.
    success = rest.SendReqNoBody("GET","/starfish.jpg");
    if (success != true) {
        Log.i(TAG, rest.lastErrorText());
        return;
        }

    // Read the response header.
    int responseStatusCode = rest.ReadResponseHeader();
    if (responseStatusCode < 0) {
        Log.i(TAG, rest.lastErrorText());
        return;
        }

    Log.i(TAG, "Response status code = " + String.valueOf(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) {
        String errResponse = rest.readRespBodyString();
        if (rest.get_LastMethodSuccess() != true) {
            Log.i(TAG, rest.lastErrorText());
            }
        else {
            Log.i(TAG, errResponse);
            }

        return;
        }

    CkStream bodyStream = new CkStream();
    // Set a 10 second read timeout for the stream. 
    // (Give up if no data arrives within 10 seconds after calling a read method.)
    bodyStream.put_ReadTimeoutMs(10000);

    // Create a background thread task to read the response body (which feeds
    // it to the bodyStream object.)
    CkTask readResponseBodyTask = rest.ReadRespBodyStreamAsync(bodyStream,true);

    // Start the task. 
    success = readResponseBodyTask.Run();

    // The application can now read the bodyStream...
    CkByteData nextChunk = new CkByteData();
    while ((bodyStream.get_EndOfStream() != true)) {

        // Read the next chunk of bytes (whatever is immediately available,
        // or wait for more data (up to 10 seconds because we set the stream's ReadTimeoutMs property)
        success = bodyStream.ReadBytes(nextChunk);
        if (success != true) {
            Log.i(TAG, "Failed to receive more response data.");
            // Make sure the background task is aborted/cancelled.
            success = readResponseBodyTask.Cancel();

            return;
            }

        // OK.. the app has the next chunk of the body, and may do whatever it wishes with it...
        // See the CkByteData online reference documentation for 
        // information about accessing and manipulating the byte data.

        }

    Log.i(TAG, "Successfully received the entire response body.");

  }

  static {
      System.loadLibrary("chilkat");

      // Note: If the incorrect library name is passed to System.loadLibrary,
      // then you will see the following error message at application startup:
      //"The application <your-application-name> has stopped unexpectedly. Please try again."
  }
}