Android Question Amazon Product advretising API in B4A

[Kerbeross]

Hi, sorry for my bad English.
I would need to interface to the API of Amazon advertising product: http://docs.aws.amazon.com/AWSECommerceService/latest/DG/Welcome.html

These are the php and java codes provided by amazon to interface with API and get the url to be queried:

PHP version:

<?php

// Your Access Key ID, as taken from the Your Account page
$access_key_id = "***";

// Your Secret Key corresponding to the above ID, as taken from the Your Account page
$secret_key = "***";

// The region you are interested in
$endpoint = "webservices.amazon.it";

$uri = "/onca/xml";

$params = array(
    "Service" => "AWSECommerceService",
    "Operation" => "ItemLookup",
    "AWSAccessKeyId" => "***",
    "AssociateTag" => "***",
    "ItemId" => "B073SBZ8YH",
    "IdType" => "ASIN",
    "ResponseGroup" => "Images,ItemAttributes,Offers"
);

// Set current timestamp if not set
if (!isset($params["Timestamp"])) {
    $params["Timestamp"] = gmdate('Y-m-d\TH:i:s\Z');
}

// Sort the parameters by key
ksort($params);

$pairs = array();

foreach ($params as $key => $value) {
    array_push($pairs, rawurlencode($key)."=".rawurlencode($value));
}

// Generate the canonical query
$canonical_query_string = join("&", $pairs);

// Generate the string to be signed
$string_to_sign = "GET\n".$endpoint."\n".$uri."\n".$canonical_query_string;

// Generate the signature required by the Product Advertising API
$signature = base64_encode(hash_hmac("sha256", $string_to_sign, $secret_key, true));

// Generate the signed URL
$request_url = 'http://'.$endpoint.$uri.'?'.$canonical_query_string.'&Signature='.rawurlencode($signature);

echo "Signed URL: \"".$request_url."\"";

?>

Java version:

package com.amazon.advertising.api.sample;

import java.util.HashMap;
import java.util.Map;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;

import org.w3c.dom.Document;
import org.w3c.dom.Node;

/*
* This class shows how to make a simple authenticated call to the
* Amazon Product Advertising API.
*
* See the README.html that came with this sample for instructions on
* configuring and running the sample.
*/
public class JavaCodeSnippet {

    /*
     * Your Access Key ID, as taken from the Your Account page.
     */
    private static final String ACCESS_KEY_ID = "***";

    /*
     * Your Secret Key corresponding to the above ID, as taken from the
     * Your Account page.
     */
    private static final String SECRET_KEY = "***";

    /*
     * Use the end-point according to the region you are interested in.
     */
    private static final String ENDPOINT = "webservices.amazon.it";

    public static void main(String[] args) {

        /*
         * Set up the signed requests helper.
         */
        SignedRequestsHelper helper;

        try {
            helper = SignedRequestsHelper.getInstance(ENDPOINT, ACCESS_KEY_ID, SECRET_KEY);
        } catch (Exception e) {
            e.printStackTrace();
            return;
        }

        String requestUrl = null;

        Map<String, String> params = new HashMap<String, String>();

        params.put("Service", "AWSECommerceService");
        params.put("Operation", "ItemLookup");
        params.put("AWSAccessKeyId", "***");
        params.put("AssociateTag", "***");
        params.put("ItemId", "B073SBZ8YH");
        params.put("IdType", "ASIN");
        params.put("ResponseGroup", "Images,ItemAttributes,Offers");

        requestUrl = helper.sign(params);

        System.out.println("Signed URL: \"" + requestUrl + "\"");
    }
}

Is there any library or class already developed that can help me? Thanks.

 

[DonManfred]

You can use okhttputils2 to communicate with Amazon.
You need to find out how to sign your request.

helper.sign(params);

 

[Kerbeross]

You need to find out how to sign your request.

Yes, this is the problem.

 

[DonManfred]

Check this: https://www.b4x.com/android/forum/t...s3-v4-signature-calculator.81006/#post-513509

 

[Kerbeross]

Thanks, I'll take a look