(Go) eBay -- Download Data using FileTransferService

Demonstrates how to download a data file using the eBay File Transfer API.

Note: This example requires Chilkat v9.5.0.67 or later.

Chilkat Go Downloads Go Package for Windows, MacOS, Linux, Alpine Linux, Solaris

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

    // Use a previously obtained access token.  The token should look something like this:
    // "AgAAAA**AQA ..."
    accessToken := "EBAY_ACCESS_TOKEN"

    http := chilkat.NewHttp()

    req := chilkat.NewHttpRequest()

    req.SetHttpVerb("POST")
    req.SetPath("/FileTransferService")
    req.SetContentType("application/xml")

    // Build the XML body for the request.
    xml := chilkat.NewXml()
    xml.SetTag("downloadFileRequest")
    xml.AddAttribute("xmlns","http://www.ebay.com/marketplace/services")
    xml.UpdateChildContent("taskReferenceId","50013004806")
    xml.UpdateChildContent("fileReferenceId","50015579016")

    req.LoadBodyFromString(*xml.GetXml(),"utf-8")

    // The XML body looks like this:

    // 	<?xml version="1.0" encoding="UTF-8"?>
    // 	<downloadFileRequest xmlns="http://www.ebay.com/marketplace/services">
    // 	<taskReferenceId>50013004806</taskReferenceId>
    // 	<fileReferenceId>50015579016</fileReferenceId>
    // 	</downloadFileRequest>

    req.AddHeader("X-EBAY-SOA-OPERATION-NAME","downloadFile")
    req.AddHeader("X-EBAY-SOA-SECURITY-TOKEN",accessToken)

    resp := http.SynchronousRequest("storage.sandbox.ebay.com",443,true,req)
    if http.LastMethodSuccess() != true {
        fmt.Println(http.LastErrorText())
        http.DisposeHttp()
        req.DisposeHttpRequest()
        xml.DisposeXml()
        return
    }

    statusCode := resp.StatusCode()
    fmt.Println("Response status code = ", statusCode)

    responseBody := chilkat.NewBinData()
    resp.GetBodyBd(responseBody)
    resp.DisposeHttpResponse()

    // We can save the response body to a file for examination if we get an unanticipated response.  
    // (It's binary, so it won't open well in a text editor.)
    responseBody.WriteFile("qa_output/response.mime")

    if statusCode != 200 {
        fmt.Println("Failed.")
        http.DisposeHttp()
        req.DisposeHttpRequest()
        xml.DisposeXml()
        responseBody.DisposeBinData()
        return
    }

    // The response body looks like this:

    // 	--MIMEBoundaryurn_uuid_2B668636C1E17A4D4114925305818684241
    // 	Content-Type: application/xop+xml; charset=utf-8; type="text/xml"
    // 	Content-Transfer-Encoding: binary
    // 	Content-ID: <0.urn:uuid:2B668636C1E17A4D4114925305818684242>
    // 
    // 	<?xml version='1.0' encoding='UTF-8'?>
    // 	<downloadFileResponse xmlns="http://www.ebay.com/marketplace/services">
    // 	<ack>Success</ack>
    // 	<version>1.1.0</version>
    // 	<timestamp>2017-04-18T15:49:41.868Z</timestamp>
    // 	<fileAttachment>
    // 	    <Size>587</Size>
    // 	    <Data>
    //                 <xop:Include xmlns:xop="http://www.w3.org/2004/08/xop/include" href="cid:urn:uuid:A37C3C73E994C267F11492530585522"/>
    // 	    </Data>
    // 	</fileAttachment>
    // 	</downloadFileResponse>
    // 	--MIMEBoundaryurn_uuid_2B668636C1E17A4D4114925305818684241
    // 	Content-Type: application/zip
    // 	Content-Transfer-Encoding: binary
    // 	Content-ID: <urn:uuid:A37C3C73E994C267F11492530585522>
    // 
    // 	<the binary bytes of the zip start here...>
    // 

    // Load the binary response into a MIME object.
    mime := chilkat.NewMime()
    success := mime.LoadMimeBd(responseBody)
    if success != true {
        fmt.Println(mime.LastErrorText())
        http.DisposeHttp()
        req.DisposeHttpRequest()
        xml.DisposeXml()
        responseBody.DisposeBinData()
        mime.DisposeMime()
        return
    }

    // Make sure we have 2 sub-parts.  The 1st sub-part is the XML response, the 2nd sub-part
    // is the zip containing the data.

    // Note: The 2nd sub-part can be a "zip" or "gzip".  These are two different file formats.
    // A zip is indicated with a Content-Type header equal to "application/zip",
    // whereas a gzip is indicated with a Content-Type header equal to "application/x-gzip"
    if mime.NumParts() != 2 {
        fmt.Println("Expected the MIME to have 2 parts.")
        fmt.Println("NumParts = ", mime.NumParts())
        fmt.Println("Failed.")
        http.DisposeHttp()
        req.DisposeHttpRequest()
        xml.DisposeXml()
        responseBody.DisposeBinData()
        mime.DisposeMime()
        return
    }

    // Get the XML from the 1st MIME sub-part.
    part0 := mime.GetPart(0)
    downloadResponseXml := part0.GetBodyDecoded()
    xmlResp := chilkat.NewXml()
    xmlResp.LoadXml(*downloadResponseXml)
    fmt.Println("Download Response XML:")
    fmt.Println(*xmlResp.GetXml())
    part0.DisposeMime()

    fmt.Println("----")

    // Now get the zip from the second part (index=1), unzip, and examine..
    part1 := mime.GetPart(1)
    zipData := chilkat.NewBinData()
    // This example requires Chilkat v9.5.0.67 or later.
    // The GetBodyBd method was added in v9.5.0.67.
    part1.GetBodyBd(zipData)

    // Check to see if we have a zip or gzip.
    sbContentType := chilkat.NewStringBuilder()
    sbContentType.Append(part1.ContentType())
    part1.DisposeMime()

    xmlFromZip := chilkat.NewXml()

    if sbContentType.Contains("gzip",false) == true {
        // This is a gzip compressed file.
        gzip := chilkat.NewGzip()

        // in-place uncompress the data.
        // Note: The UncompressBd method was added in Chilkat v9.5.0.67
        success = gzip.UncompressBd(zipData)
        if success != true {
            fmt.Println(gzip.LastErrorText())
            http.DisposeHttp()
            req.DisposeHttpRequest()
            xml.DisposeXml()
            responseBody.DisposeBinData()
            mime.DisposeMime()
            xmlResp.DisposeXml()
            zipData.DisposeBinData()
            sbContentType.DisposeStringBuilder()
            xmlFromZip.DisposeXml()
            gzip.DisposeGzip()
            return
        }

        xmlFromZip.LoadXml(*zipData.GetString("utf-8"))

    }
    else {
        // This is a zip archive.

        // Load the body into a Zip object.
        zip := chilkat.NewZip()
        success = zip.OpenBd(zipData)
        if success != true {
            fmt.Println(zip.LastErrorText())
            http.DisposeHttp()
            req.DisposeHttpRequest()
            xml.DisposeXml()
            responseBody.DisposeBinData()
            mime.DisposeMime()
            xmlResp.DisposeXml()
            zipData.DisposeBinData()
            sbContentType.DisposeStringBuilder()
            xmlFromZip.DisposeXml()
            gzip.DisposeGzip()
            zip.DisposeZip()
            return
        }

        // Save the .zip to a file (so we can examine it for debugging if something is not as expected)
        zipData.WriteFile("qa_output/ebay_data.zip")

        // The zip should contain a single XML file.
        if zip.NumEntries() != 1 {
            fmt.Println("Expected the .zip to have 1 entry.")
            fmt.Println("NumEntries = ", zip.NumEntries())
            fmt.Println("Failed.")
            http.DisposeHttp()
            req.DisposeHttpRequest()
            xml.DisposeXml()
            responseBody.DisposeBinData()
            mime.DisposeMime()
            xmlResp.DisposeXml()
            zipData.DisposeBinData()
            sbContentType.DisposeStringBuilder()
            xmlFromZip.DisposeXml()
            gzip.DisposeGzip()
            zip.DisposeZip()
            return
        }

        entry := zip.GetEntryByIndex(0)

        xmlFromZip.LoadXml(*entry.UnzipToString(0,"utf-8"))
        entry.DisposeZipEntry()
    }

    fmt.Println("XML contained in the zip:")
    fmt.Println(*xmlFromZip.GetXml())
    fmt.Println("----")

    fmt.Println("Success.")

    http.DisposeHttp()
    req.DisposeHttpRequest()
    xml.DisposeXml()
    responseBody.DisposeBinData()
    mime.DisposeMime()
    xmlResp.DisposeXml()
    zipData.DisposeBinData()
    sbContentType.DisposeStringBuilder()
    xmlFromZip.DisposeXml()
    gzip.DisposeGzip()
    zip.DisposeZip()