【背景】
折腾：
过程中，想要试试ResponseGroup的Accessories。
【折腾过程】
完整代码：
（1）SignedRequestHelper.cs
/*
* [Function]
* Implement Amazon AWS API, focus on ItemLookup, ItemSearch, BrowseNodeLookup
* code based on:
* Product Advertising API Signed Requests Sample Code - C# REST/QUERY
* http://aws.amazon.com/code/Product-Advertising-API/2480
* ->
* http://associates-amazon.s3.amazonaws.com/signed-requests/samples/amazon-product-advt-api-sample-csharp-query.zip
*
* [Author]
* Crifan Li
*
* [Date]
* 2013-06-13
*
* [Contact]
* https://www.crifan.org/contact_me/
*/
using System;
using System.Collections.Generic;
using System.Text;
using System.Web;
using System.Security.Cryptography;
namespace AmazonProductAdvtApi
{
class SignedRequestHelper
{
private string endPoint;
private string akid;
//added by Crifan Li
//https://affiliate-program.amazon.co.uk/gp/advertising/api/detail/api-changes.html?ie=UTF8&pf_rd_t=501&ref_=amb_link_83388313_2&pf_rd_m=A3P5ROKL5A1OLE&pf_rd_p=&pf_rd_s=assoc-center-1&pf_rd_r=&pf_rd_i=assoc-api-detail-2-v2
//Product Advertising API Change Details
//Associate Tag Parameter: Every request made to the API should include a valid Associate Tag. Any request that does not contain a valid Associate Tag will be rejected with an appropriate error message. For details on the Associate Tag parameter, please refer to our Developer guide.
//-> must add this Associate Tag, otherwise will return:
//<Error>
// <Code>AWS.MissingParameters</Code>
// <Message>Your request is missing required parameters. Required parameters include AssociateTag.</Message>
//</Error>
private string associateTag;
private byte[] secret;
private HMAC signer;
private const string REQUEST_URI = "/onca/xml";
private const string REQUEST_METHOD = "GET";
/*
* Use this constructor to create the object. The AWS credentials are available on
* http://aws.amazon.com
*
* The destination is the service end-point for your application:
* US: ecs.amazonaws.com
* JP: ecs.amazonaws.jp
* UK: ecs.amazonaws.co.uk
* DE: ecs.amazonaws.de
* FR: ecs.amazonaws.fr
* CA: ecs.amazonaws.ca
*/
public SignedRequestHelper(string awsAccessKeyId, string awsSecretKey, string awsAssociateTag, string destination)
{
this.endPoint = destination.ToLower();
this.akid = awsAccessKeyId;
//added by Crifan Li
this.associateTag = awsAssociateTag;
this.secret = Encoding.UTF8.GetBytes(awsSecretKey);
this.signer = new HMACSHA256(this.secret);
}
/*
* Sign a request in the form of a Dictionary of name-value pairs.
*
* This method returns a complete URL to use. Modifying the returned URL
* in any way invalidates the signature and Amazon will reject the requests.
*/
public string Sign(IDictionary<string, string> request)
{
// Use a SortedDictionary to get the parameters in naturual byte order, as
// required by AWS.
ParamComparer pc = new ParamComparer();
SortedDictionary<string, string> sortedMap = new SortedDictionary<string, string>(request, pc);
// Add the AWSAccessKeyId and Timestamp to the requests.
sortedMap["AWSAccessKeyId"] = this.akid;
//added by Crifan Li
sortedMap["AssociateTag"] = this.associateTag;
sortedMap["Timestamp"] = this.GetTimestamp();
// Get the canonical query string
string canonicalQS = this.ConstructCanonicalQueryString(sortedMap);
// Derive the bytes needs to be signed.
StringBuilder builder = new StringBuilder();
builder.Append(REQUEST_METHOD)
.Append("\n")
.Append(this.endPoint)
.Append("\n")
.Append(REQUEST_URI)
.Append("\n")
.Append(canonicalQS);
string stringToSign = builder.ToString();
byte[] toSign = Encoding.UTF8.GetBytes(stringToSign);
// Compute the signature and convert to Base64.
byte[] sigBytes = signer.ComputeHash(toSign);
string signature = Convert.ToBase64String(sigBytes);
// now construct the complete URL and return to caller.
StringBuilder qsBuilder = new StringBuilder();
qsBuilder.Append("http://")
.Append(this.endPoint)
.Append(REQUEST_URI)
.Append("?")
.Append(canonicalQS)
.Append("&Signature=")
.Append(this.PercentEncodeRfc3986(signature));
return qsBuilder.ToString();
}
/*
* Sign a request in the form of a query string.
*
* This method returns a complete URL to use. Modifying the returned URL
* in any way invalidates the signature and Amazon will reject the requests.
*/
public string Sign(string queryString)
{
IDictionary<string, string> request = this.CreateDictionary(queryString);
return this.Sign(request);
}
/*
* Current time in IS0 8601 format as required by Amazon
*/
private string GetTimestamp()
{
DateTime currentTime = DateTime.UtcNow;
string timestamp = currentTime.ToString("yyyy-MM-ddTHH:mm:ssZ");
return timestamp;
}
/*
* Percent-encode (URL Encode) according to RFC 3986 as required by Amazon.
*
* This is necessary because .NET's HttpUtility.UrlEncode does not encode
* according to the above standard. Also, .NET returns lower-case encoding
* by default and Amazon requires upper-case encoding.
*/
private string PercentEncodeRfc3986(string str)
{
str = HttpUtility.UrlEncode(str, System.Text.Encoding.UTF8);
str = str.Replace("'", "%27").Replace("(", "%28").Replace(")", "%29").Replace("*", "%2A").Replace("!", "%21").Replace("%7e", "~").Replace("+", "%20");
StringBuilder sbuilder = new StringBuilder(str);
for (int i = 0; i < sbuilder.Length; i++)
{
if (sbuilder[i] == '%')
{
if (Char.IsLetter(sbuilder[i + 1]) || Char.IsLetter(sbuilder[i + 2]))
{
sbuilder[i + 1] = Char.ToUpper(sbuilder[i + 1]);
sbuilder[i + 2] = Char.ToUpper(sbuilder[i + 2]);
}
}
}
return sbuilder.ToString();
}
/*
* Convert a query string to corresponding dictionary of name-value pairs.
*/
private IDictionary<string, string> CreateDictionary(string queryString)
{
Dictionary<string, string> map = new Dictionary<string, string>();
string[] requestParams = queryString.Split('&');
for (int i = 0; i < requestParams.Length; i++)
{
if (requestParams[i].Length < 1)
{
continue;
}
char[] sep = { '=' };
string[] param = requestParams[i].Split(sep, 2);
for (int j = 0; j < param.Length; j++)
{
param[j] = HttpUtility.UrlDecode(param[j], System.Text.Encoding.UTF8);
}
switch (param.Length)
{
case 1:
{
if (requestParams[i].Length >= 1)
{
if (requestParams[i].ToCharArray()[0] == '=')
{
map[""] = param[0];
}
else
{
map[param[0]] = "";
}
}
break;
}
case 2:
{
if (!string.IsNullOrEmpty(param[0]))
{
map[param[0]] = param[1];
}
}
break;
}
}
return map;
}
/*
* Consttuct the canonical query string from the sorted parameter map.
*/
private string ConstructCanonicalQueryString(SortedDictionary<string, string> sortedParamMap)
{
StringBuilder builder = new StringBuilder();
if (sortedParamMap.Count == 0)
{
builder.Append("");
return builder.ToString();
}
foreach (KeyValuePair<string, string> kvp in sortedParamMap)
{
builder.Append(this.PercentEncodeRfc3986(kvp.Key));
builder.Append("=");
builder.Append(this.PercentEncodeRfc3986(kvp.Value));
builder.Append("&");
}
string canonicalString = builder.ToString();
canonicalString = canonicalString.Substring(0, canonicalString.Length - 1);
return canonicalString;
}
}
/*
* To help the SortedDictionary order the name-value pairs in the correct way.
*/
class ParamComparer : IComparer<string>
{
public int Compare(string p1, string p2)
{
return string.CompareOrdinal(p1, p2);
}
}
}（2）ItemLookupSample.cs
/*
* [Function]
* Implement Amazon AWS API, focus on ItemLookup, ItemSearch, BrowseNodeLookup
* code based on:
* Product Advertising API Signed Requests Sample Code - C# REST/QUERY
* http://aws.amazon.com/code/Product-Advertising-API/2480
* ->
* http://associates-amazon.s3.amazonaws.com/signed-requests/samples/amazon-product-advt-api-sample-csharp-query.zip
*
* [Author]
* Crifan Li
*
* [Date]
* 2013-06-20
*
* [Contact]
* https://www.crifan.org/contact_me/
*/
using System;
using System.Collections.Generic;
using System.Text;
using System.Net;
using System.IO;
using System.Xml;
using System.Xml.XPath;
namespace AmazonProductAdvtApi
{
class ItemLookupSample
{
private const string awsAccessKeyId = "xxx";
private const string awsSecretKey = "xxx";
private const string awsAssociateTag = "xxx";
private const string awsDestination = "ecs.amazonaws.com";
//【记录】寻找AWSECommerceService的最新版本
//https://www.crifan.org/find_awsecommerceservice_latest_version
//private const string awsApiVersion = "2011-08-02";
private const string awsApiVersion = "2011-08-01";
//private const string NAMESPACE = "http://webservices.amazon.com/AWSECommerceService/2009-03-31";
//private const string NAMESPACE = "http://webservices.amazon.com/AWSECommerceService/2011-08-01";
private const string NAMESPACE = "http://webservices.amazon.com/AWSECommerceService/" + awsApiVersion;
//private const string ITEM_ID = "0545010225";
//private const string ITEM_ID = "B0083PWAPW";
//<Item>
// <ASIN>B0083PWAPW</ASIN>
// <ParentASIN>B008GGCAVM</ParentASIN>
//</Item>
private const string ITEM_ID = "B008GGCAVM";
private static void itemSearchTest(SignedRequestHelper helper)
{
/*
* Here is an ItemLookup example where the request is stored as a dictionary.
*/
IDictionary<string, string> reqDict = new Dictionary<string, String>();
reqDict["Service"] = "AWSECommerceService";
reqDict["Version"] = awsApiVersion;
reqDict["Operation"] = "ItemSearch";
//reqDict["SearchIndex"] = "None";
reqDict["SearchIndex"] = "HomeGarden";
reqDict["ResponseGroup"] = "ItemIds";
//Home & Kitchen -> Heating, Cooling & Air Quality -> Air Conditioners & Accessories -> Energy Star Qualified
//reqDict["BrowseNodeId"] = "3737761";
reqDict["BrowseNode"] = "3737761";
reqDict["ItemPage"] = "6";
String requestUrl = helper.Sign(reqDict);
WebRequest request = HttpWebRequest.Create(requestUrl);
WebResponse response = request.GetResponse();
XmlDocument doc = new XmlDocument();
doc.Load(response.GetResponseStream());
//for debug
System.Console.WriteLine(doc.InnerXml);
}
private static void browseNodeLookupTest(SignedRequestHelper helper)
{
/*
* Here is an ItemLookup example where the request is stored as a dictionary.
*/
IDictionary<string, string> reqDict = new Dictionary<string, String>();
reqDict["Service"] = "AWSECommerceService";
reqDict["Version"] = awsApiVersion;
reqDict["Operation"] = "BrowseNodeLookup";
//http://docs.aws.amazon.com/AWSECommerceService/latest/DG/BrowseNodeIDs.html
//2619525011 -> Appliances
//reqDict["BrowseNodeId"] = "2619525011";
//<BrowseNodeId>2619525011</BrowseNodeId>
//<Name>Appliances</Name>
//<Children>
// <BrowseNode>
// <BrowseNodeId>2619526011</BrowseNodeId>
// <Name>Categories</Name>
// <IsCategoryRoot>1</IsCategoryRoot>
// </BrowseNode>
//reqDict["BrowseNodeId"] = "2619526011";
//<Children>
// <BrowseNode>
// <BrowseNodeId>3737671</BrowseNodeId>
// <Name>Air Conditioners</Name>
// </BrowseNode>
//reqDict["BrowseNodeId"] = "3737671";
//<BrowseNode>
// <BrowseNodeId>3737671</BrowseNodeId>
// <Name>Air Conditioners & Accessories</Name>
// <Children>
// <BrowseNode>
// <BrowseNodeId>3737761</BrowseNodeId>
// <Name>Energy Star Qualified</Name>
// </BrowseNode>
reqDict["BrowseNodeId"] = "3737761";
reqDict["ResponseGroup"] = "BrowseNodeInfo";
/*
* The helper supports two forms of requests - dictionary form and query string form.
*/
String requestUrl;
requestUrl = helper.Sign(reqDict);
WebRequest request = HttpWebRequest.Create(requestUrl);
WebResponse response = request.GetResponse();
XmlDocument doc = new XmlDocument();
doc.Load(response.GetResponseStream());
//for debug
System.Console.WriteLine(doc.InnerXml);
}
public static void Main()
{
SignedRequestHelper helper = new SignedRequestHelper(awsAccessKeyId, awsSecretKey, awsAssociateTag, awsDestination);
//itemSearchTest(helper);
//browseNodeLookupTest(helper);
/*
* Here is an ItemLookup example where the request is stored as a dictionary.
*/
IDictionary<string, string> reqDict = new Dictionary<string, String>();
reqDict["Service"] = "AWSECommerceService";
//r1["Version"] = "2009-03-31";
//r1["Version"] = "2009-03-31";
//reqDict["Version"] = "2011-08-02";
reqDict["Version"] = "2011-08-01";
reqDict["Operation"] = "ItemLookup";
reqDict["IdType"] = "ASIN";
//reqDict["ItemId"] = ITEM_ID;
string asin = "B00008OE6I";
reqDict["ItemId"] = asin;
//reqDict["ResponseGroup"] = "Small";
//reqDict["ResponseGroup"] = "OfferSummary";
//reqDict["ResponseGroup"] = "ItemAttributes";
//reqDict["ResponseGroup"] = "VariationSummary";
//reqDict["ResponseGroup"] = "Variations";
reqDict["ResponseGroup"] = "Accessories";
/*
* The helper supports two forms of requests - dictionary form and query string form.
*/
String requestUrl;
String title;
requestUrl = helper.Sign(reqDict);
title = FetchTitle(requestUrl);
System.Console.WriteLine("Method 1: ItemLookup Dictionary form.");
System.Console.WriteLine("Title is \"" + title + "\"");
System.Console.WriteLine();
}
private static string FetchTitle(string url)
{
try
{
WebRequest request = HttpWebRequest.Create(url);
WebResponse response = request.GetResponse();
XmlDocument doc = new XmlDocument();
doc.Load(response.GetResponseStream());
//for debug
System.Console.WriteLine(doc.InnerXml);
XmlNodeList errorMessageNodes = doc.GetElementsByTagName("Message", NAMESPACE);
if (errorMessageNodes != null && errorMessageNodes.Count > 0)
{
String message = errorMessageNodes.Item(0).InnerText;
return "Error: " + message + " (but signature worked)";
}
XmlNode titleNode = doc.GetElementsByTagName("Title", NAMESPACE).Item(0);
string title = titleNode.InnerText;
response.Close();
return title;
}
catch (Exception e)
{
System.Console.WriteLine("Caught Exception: " + e.Message);
System.Console.WriteLine("Stack Trace: " + e.StackTrace);
}
return null;
}
}
}返回的xml：
<?xml version="1.0"?>
<ItemLookupResponse xmlns="http://webservices.amazon.com/AWSECommerceService/2011-08-01">
<OperationRequest>
<RequestId>f5a92ab1-b0cc-4c06-8e66-c19f15c09755</RequestId>
<Arguments>
<Argument Name="Operation" Value="ItemLookup"/>
<Argument Name="Service" Value="AWSECommerceService"/>
<Argument Name="Signature" Value="dRaS8ZqIAByaffZwxbgmyRNl4BVTfjpRyhzsdAMOLkM="/>
<Argument Name="AssociateTag" Value="xxx"/>
<Argument Name="Version" Value="2011-08-01"/>
<Argument Name="ItemId" Value="B00008OE6I"/>
<Argument Name="IdType" Value="ASIN"/>
<Argument Name="AWSAccessKeyId" Value="xxx"/>
<Argument Name="Timestamp" Value="2013-06-20T10:20:47Z"/>
<Argument Name="ResponseGroup" Value="Accessories"/>
</Arguments>
<RequestProcessingTime>0.1040580000000000</RequestProcessingTime>
</OperationRequest>
<Items>
<Request>
<IsValid>True</IsValid>
<ItemLookupRequest>
<IdType>ASIN</IdType>
<ItemId>B00008OE6I</ItemId>
<ResponseGroup>Accessories</ResponseGroup>
<VariationPage>All</VariationPage>
</ItemLookupRequest>
</Request>
<Item>
<ASIN>B00008OE6I</ASIN>
<Accessories>
<Accessory>
<ASIN>B001EUIWGY</ASIN>
<Title>Adobe Photoshop CS4 Upgrade [OLD VERSION]</Title>
</Accessory>
<Accessory>
<ASIN>B001TH7GUA</ASIN>
<Title>AmazonBasics Hi-Speed USB 2.0 A-Male to B-Male Cable (6 Feet / 1.8 Meters)</Title>
</Accessory>
<Accessory>
<ASIN>B001TH7GUK</ASIN>
<Title>AmazonBasics USB 2.0 A-Male to Mini-B Cable (6 Feet / 1.8 Meters)</Title>
</Accessory>
<Accessory>
<ASIN>B001TH7GUU</ASIN>
<Title>AmazonBasics USB 2.0 A-Male to A-Female Extension Cable (9.8 Feet/3.0 Meters)</Title>
</Accessory>
<Accessory>
<ASIN>B001TH7GV4</ASIN>
<Title>AmazonBasics USB 2.0 A-Male to A-Female Extension Cable (3.3 Feet/1.0 Meter)</Title>
</Accessory>
</Accessories>
</Item>
</Items>
</ItemLookupResponse>3.后来又用别的asin：
string asin = "B004ZGN6MY";
//string asin = "B00008OE6I";
reqDict["ItemId"] = asin;返回结果为：
<?xml version="1.0"?>
<ItemLookupResponse xmlns="http://webservices.amazon.com/AWSECommerceService/2011-08-01">
<OperationRequest>
<RequestId>48b5b9c6-32a2-4794-aa20-c9d0f6ef2bd8</RequestId>
<Arguments>
<Argument Name="Operation" Value="ItemLookup"/>
<Argument Name="Service" Value="AWSECommerceService"/>
<Argument Name="AssociateTag" Value="xxx"/>
<Argument Name="Version" Value="2011-08-01"/>
<Argument Name="Signature" Value="6+7JlDh+k1dToB73SWnVpEPYvie9qG7qldyDG4pwD6c="/>
<Argument Name="ItemId" Value="B004ZGN6MY"/>
<Argument Name="IdType" Value="ASIN"/>
<Argument Name="AWSAccessKeyId" Value="xxx"/>
<Argument Name="Timestamp" Value="2013-06-20T10:25:25Z"/>
<Argument Name="ResponseGroup" Value="Accessories"/>
</Arguments>
<RequestProcessingTime>0.0152580000000000</RequestProcessingTime>
</OperationRequest>
<Items>
<Request>
<IsValid>True</IsValid>
<ItemLookupRequest>
<IdType>ASIN</IdType>
<ItemId>B004ZGN6MY</ItemId>
<ResponseGroup>Accessories</ResponseGroup>
<VariationPage>All</VariationPage>
</ItemLookupRequest>
</Request>
<Item>
<ASIN>B004ZGN6MY</ASIN>
</Item>
</Items>
</ItemLookupResponse>说明是没有附件。
【总结】
ResponseGroup的Accessories，可以返回某产品是否有附件。
更多细节，可参考：
相关参考：
【整理】C#版的AWS的ResponseGroup的Small示例代码
【整理】C#版的AWS的ResponseGroup的ItemAttributes示例代码
【整理】C#版的AWS的ResponseGroup的VariationSummary示例代码
【整理】C#版的AWS的ResponseGroup的Variations示例代码