Go

REST Receive Response in Chunks

See more REST Examples

Demonstrates how to receive a REST HTTP response in chunks.

Note: This example requires Chilkat 10.1.0 or greater.

Go

    success := false

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

    rest := chilkat.NewRest()

    // Connect to the web server
    bTls := true
    port := 443
    bAutoReconnect := true
    success = rest.Connect("chilkatsoft.com",port,bTls,bAutoReconnect)
    if success == false {
        fmt.Println(rest.LastErrorText())
        rest.DisposeRest()
        return
    }

    // Send the request.
    // This can be *any* kind of request: POST, GET, PUT, etc. using *any* of the Chilkat REST methods that send requests.
    // For this example, we'll just GET a simple XML document that is about 274K in size.

    success = rest.SendReqNoBody("GET","/hamlet.xml")
    if success == false {
        fmt.Println(rest.LastErrorText())
        rest.DisposeRest()
        return
    }

    // Get the response header.
    statusCode := rest.ReadResponseHeader()
    if statusCode < 0 {
        fmt.Println(rest.LastErrorText())
        rest.DisposeRest()
        return
    }

    fmt.Println("response status code = ", statusCode)

    outputFile := "c:/temp/qa_output/hamlet.xml"

    fac := chilkat.NewFileAccess()
    success = fac.OpenForWrite(outputFile)
    if statusCode < 0 {
        fmt.Println(fac.LastErrorText())
        rest.DisposeRest()
        fac.DisposeFileAccess()
        return
    }

    // Get the response in chunks.
    // (Note: There are more efficient ways to simply download a file from a web server, such as by calling Chilkat's Http.Download method.
    // The purpose of this method is to show how to receive a response chunk-by-chunk.)
    bd := chilkat.NewBinData()
    status := 1
    for status == 1 {
        // Read a minimum of 16000 bytes.
        // Note: Because of TLS message lengths, or the possibility of the response being either compressed (gzip/deflate) or in the HTTP chunked encoding,
        // the amount of data received in each call can be greater than the specified min size.
        // Chilkat will return from the call as soon as it has received an amount equal to or more than the specified size,
        // except for the very last chunk, which can be less that the min size or even 0 bytes.

        // The status will be one of three values:
        // -1 = error
        // 0 = received the last chunk of the response.
        // 1 = received a chunk, and more chunks are coming..

        // The received data is *appended* to the contents of the BinData object.
        status = rest.ReadRespChunkBd(16000,bd)
        if status >= 0 {
            fmt.Println("Received chunk: ", bd.NumBytes(), " bytes")
            fac.FileWriteBd(bd,0,0)
            bd.Clear()
        }

    }

    fac.FileClose()

    fmt.Println("Success.")

    rest.DisposeRest()
    fac.DisposeFileAccess()
    bd.DisposeBinData()