DataFlex

REST Stream Response to File (Streaming Download) (Amazon S3)

See more Amazon S3 (new) Examples

Demonstrates how to stream the response body directly to a file. (The example shows how to stream a JPG from the Amazon S3 service.) DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoRest
    Boolean iBTls
    Integer iPort
    Boolean iBAutoReconnect
    Variant vAuthAws
    Handle hoAuthAws
    Integer iResponseStatusCode
    Variant vBodyStream
    Handle hoBodyStream
    String sErrResponse
    String sTemp1
    Boolean bTemp1

    Move False To iSuccess

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

    Get Create (RefClass(cComChilkatRest)) To hoRest
    If (Not(IsComObjectCreated(hoRest))) Begin
        Send CreateComObject of hoRest
    End

    // Connect to the Amazon AWS REST server.
    Move True To iBTls
    Move 443 To iPort
    Move True To iBAutoReconnect
    Get ComConnect Of hoRest "s3.amazonaws.com" iPort iBTls iBAutoReconnect To iSuccess

    // ----------------------------------------------------------------------------
    // 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.
    Get Create (RefClass(cComChilkatAuthAws)) To hoAuthAws
    If (Not(IsComObjectCreated(hoAuthAws))) Begin
        Send CreateComObject of hoAuthAws
    End
    Set ComAccessKey Of hoAuthAws To "AWS_ACCESS_KEY"
    Set ComSecretKey Of hoAuthAws To "AWS_SECRET_KEY"
    Set ComServiceName Of hoAuthAws To "s3"
    Get pvComObject of hoAuthAws to vAuthAws
    Get ComSetAuthAws Of hoRest vAuthAws To iSuccess

    // Set the bucket name via the HOST header.
    // In this case, the bucket name is "chilkat100".
    Set ComHost Of hoRest To "chilkat100.s3.amazonaws.com"

    // Send the request to download the JPG.
    Get ComSendReqNoBody Of hoRest "GET" "/starfish.jpg" To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoRest To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Read the response header.
    Get ComReadResponseHeader Of hoRest To iResponseStatusCode
    If (iResponseStatusCode < 0) Begin
        Get ComLastErrorText Of hoRest To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Showln "Response status code = " iResponseStatusCode

    // 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 (iResponseStatusCode = 200) Begin

        Get Create (RefClass(cComChilkatStream)) To hoBodyStream
        If (Not(IsComObjectCreated(hoBodyStream))) Begin
            Send CreateComObject of hoBodyStream
        End

        // The stream's sink will be a file.
        Set ComSinkFile Of hoBodyStream To "qa_output/starfish.jpg"

        // Read the response body to the stream.  Given that we've
        // set the stream's sink to a file, it will stream directly
        // to the file.
        Get pvComObject of hoBodyStream to vBodyStream
        Get ComReadRespBodyStream Of hoRest vBodyStream True To iSuccess
        If (iSuccess <> True) Begin
            Get ComLastErrorText Of hoRest To sTemp1
            Showln sTemp1
            Procedure_Return
        End

        Showln "Successfully received the JPG file."

    End
    Else Begin
        Get ComReadRespBodyString Of hoRest To sErrResponse
        Get ComLastMethodSuccess Of hoRest To bTemp1
        If (bTemp1 <> True) Begin
            Get ComLastErrorText Of hoRest To sTemp1
            Showln sTemp1
        End
        Else Begin
            Showln sErrResponse
        End

    End



End_Procedure