Progress bars

You can use progress bars to indicate the upload or download progress.

The following code is used as an example to describe how to view progress information with Bucket.GetObjectToFile:

package main

import (
	"fmt"
	"os"
	"github.com/aliyun/aliyun-oss-go-sdk/oss"
)

// Define a progress bar listener.
type OssProgressListener struct {
}

// Define the progress event handler.
func (listener *OssProgressListener) ProgressChanged(event *oss.ProgressEvent) {
	switch event.EventType {
	case oss.TransferStartedEvent:
		fmt.Printf("Transfer Started, ConsumedBytes: %d, TotalBytes %d.\n",
			event.ConsumedBytes, event.TotalBytes)
	case oss.TransferDataEvent:
		fmt.Printf("\rTransfer Data, ConsumedBytes: %d, TotalBytes %d, %d%%.",
			event.ConsumedBytes, event.TotalBytes, event.ConsumedBytes*100/event.TotalBytes)
	case oss.TransferCompletedEvent:
		fmt.Printf("\nTransfer Completed, ConsumedBytes: %d, TotalBytes %d.\n",
			event.ConsumedBytes, event.TotalBytes)
	case oss.TransferFailedEvent:
		fmt.Printf("\nTransfer Failed, ConsumedBytes: %d, TotalBytes %d.\n",
			event.ConsumedBytes, event.TotalBytes)
	default:
	}
}

func main() {
	// Create an OSSClient instance.
	client, err := oss.New("<yourEndpoint>", "<yourAccessKeyId>", "<yourAccessKeySecret>")
	if err ! = nil {
		fmt.Println("Error:", err)
		os.Exit(-1)
	}

	bucketName := "<yourBucketName>"
	objectName := "<yourObjectName>"
	localFile := "<yourLocalFile>"

	// Obtain the bucket.
	bucket, err := client.Bucket(bucketName)
	if err ! = nil {
		fmt.Println("Error:", err)
		os.Exit(-1)
	}

	// Download with a progress bar displayed.
	err = bucket.GetObjectToFile(objectName, localFile, oss.Progress(&OssProgressListener{}))
	if err ! = nil {
	fmt.Println("Error:", err)
	os.Exit(-1)
	}
	fmt.Println("Transfer Completed.")
}