获取Amazon产品API示例代码（PHP）中的错误

我下载了，正在浏览示例代码。我在sampleSettings.php文件中配置了“AWS_API_KEY”、“AWS_API_SECRET_KEY”、“AWS_ASSOCIATE_TAG”、“AWS_另一个_ASSOCIATE_TAG”的值。在尝试访问“sampleItemSearch.php”时，我在浏览器中遇到了下面提到的错误

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SOAP-ERROR:解析WSDL:无法从“”加载：需要开始标记，我终于解决了这个问题。下面提到的代码运行良好

    AWSAccessKeyId   = "*******************";
    $SecretAccessKey = "******************************";
    $AssociateTag    = "***************";

    $ItemId = '****'; //10 or 13 digit isbn
    $Timestamp = gmdate("Y-m-d\TH:i:s\Z");
    $Timestamp = str_replace(":", "%3A", $Timestamp);
    $ResponseGroup = "ItemAttributes,Images";
    $ResponseGroup = str_replace(",", "%2C", $ResponseGroup);


    $String = "AWSAccessKeyId=$AWSAccessKeyId&AssociateTag=$AssociateTag&IdType=ISBN&ItemId=$ItemId&Operation=ItemLookup&ResponseGroup=$ResponseGroup&SearchIndex=Books&Service=AWSECommerceService&Timestamp=$Timestamp&Version=2011-08-01";

    $String = str_replace("\n", "", $String);

    $Prepend = "GET\nwebservices.amazon.com\n/onca/xml\n";
    $PrependString = $Prepend . $String;

    $Signature = base64_encode(hash_hmac("sha256", $PrependString, $SecretAccessKey, True));

    $Signature = str_replace("+", "%2B", $Signature);
    $Signature = str_replace("=", "%3D", $Signature);

    $BaseUrl = "http://webservices.amazon.com/onca/xml?";
    $SignedRequest = $BaseUrl . $String . "&Signature=" . $Signature;

    $XML  = simplexml_load_file($SignedRequest);

    print_r($xml); // output

您应该使用urlencode（）而不是str_replace，代码越少，效率越高！