Streaming download with OSS Go SDK V1 - Object Storage Service

Dosya büyük olduğunda veya tek seferlik indirme çok uzun sürdüğünde içeriği artımlı olarak işlemek için akışlı indirmeyi kullanın.

Notlar

Bu konuda Çin (Hangzhou) bölgesinin genel uç noktası kullanılmaktadır. OSS ile aynı bölgedeki diğer Alibaba Cloud hizmetlerinden OSS'e erişmek istiyorsanız dahili uç nokta kullanın. OSS bölgeleri ve uç noktaları hakkında daha fazla bilgi için bkz. Bölgeler ve uç noktalar.
Bu konuda erişim kimlik bilgileri ortam değişkenlerinden alınır. Erişim kimlik bilgilerini yapılandırma hakkında daha fazla bilgi için bkz. Erişim kimlik bilgilerini yapılandırma.
Bu konu, bir OSS uç noktası kullanarak OSSClient örneğinin nasıl oluşturulacağını gösterir. Özel alan adı kullanma veya Security Token Service (STS) kimlik bilgileriyle kimlik doğrulama gibi alternatif yapılandırmalar için bkz. İstemciyi yapılandırma (Go SDK V1).
Akışlı indirmeyi kullanmak için oss:GetObject iznine sahip olmanız gerekir. Daha fazla bilgi için bkz. Özel ilke atama.

Bir nesneyi akışa indirme

Aşağıdaki kod bir nesneyi akışa indirir:

package main

import (
	"io"
	"log"

	"github.com/aliyun/aliyun-oss-go-sdk/oss"
)

func main() {
	// Obtain access credentials from environment variables. Before you run this sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are set.
	provider, err := oss.NewEnvironmentVariableCredentialsProvider()
	if err != nil {
		log.Fatalf("Failed to create credentials provider: %v", err)
	}

	// Create an OSSClient instance.
	// Set yourEndpoint to the Endpoint of the bucket. For example, for a bucket in the China (Hangzhou) region, set the Endpoint to https://oss-cn-hangzhou.aliyuncs.com. For other regions, set the Endpoint as needed.
	// Set yourRegion to the region where the bucket is located. For example, for a bucket in the China (Hangzhou) region, set the region to cn-hangzhou. For other regions, set the region as needed.
	clientOptions := []oss.ClientOption{oss.SetCredentialsProvider(&provider)}
	clientOptions = append(clientOptions, oss.Region("yourRegion"))
	// Set the signature version.
	clientOptions = append(clientOptions, oss.AuthVersion(oss.AuthV4))
	client, err := oss.New("yourEndpoint", "", "", clientOptions...)
	if err != nil {
		log.Fatalf("Failed to create OSS client: %v", err)
	}

	// Set yourBucketName to the name of the bucket.
	bucket, err := client.Bucket("yourBucketName")
	if err != nil {
		log.Fatalf("Failed to get bucket: %v", err)
	}

	// Download the object to a stream.
	body, err := bucket.GetObject("yourObjectName")
	if err != nil {
		log.Fatalf("Failed to get object: %v", err)
	}
	// After the data is read, close the stream. Otherwise, a connection leak may occur. This can exhaust the connection pool and cause the program to stop working.
	defer body.Close()

	data, err := io.ReadAll(body)
	if err != nil {
		log.Fatalf("Failed to read all data from object: %v", err)
	}
	log.Println("Data:", string(data))
}

Bir nesneyi arabelleğe indirme

Aşağıdaki kod bir nesneyi arabelleğe indirir:

package main

import (
	"bytes"
	"io"
	"log"

	"github.com/aliyun/aliyun-oss-go-sdk/oss"
)

func main() {
	// Obtain access credentials from environment variables. Before you run this sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are set.
	provider, err := oss.NewEnvironmentVariableCredentialsProvider()
	if err != nil {
		log.Fatalf("Failed to create credentials provider: %v", err)
	}

	// Create an OSSClient instance.
	// Set yourEndpoint to the Endpoint of the bucket. For example, for a bucket in the China (Hangzhou) region, set the Endpoint to https://oss-cn-hangzhou.aliyuncs.com. For other regions, set the Endpoint as needed.
	// Set yourRegion to the region where the bucket is located. For example, for a bucket in the China (Hangzhou) region, set the region to cn-hangzhou. For other regions, set the region as needed.
	clientOptions := []oss.ClientOption{oss.SetCredentialsProvider(&provider)}
	clientOptions = append(clientOptions, oss.Region("yourRegion"))
	// Set the signature version.
	clientOptions = append(clientOptions, oss.AuthVersion(oss.AuthV4))
	client, err := oss.New("yourEndpoint", "", "", clientOptions...)
	if err != nil {
		log.Fatalf("Failed to create OSS client: %v", err)
	}

	// Set yourBucketName to the name of the bucket.
	bucketName := "yourBucketName" // Replace this with the actual bucket name.
	bucket, err := client.Bucket(bucketName)
	if err != nil {
		log.Fatalf("Failed to get bucket: %v", err)
	}

	// Download the object to a buffer.
	// Set yourObjectName to the full path of the object. The full path does not include the bucket name.
	objectName := "yourObjectName" // Replace this with the actual object path.
	body, err := bucket.GetObject(objectName)
	if err != nil {
		log.Fatalf("Failed to get object: %v", err)
	}
	defer body.Close()

	buf := new(bytes.Buffer)
	_, err = io.Copy(buf, body)
	if err != nil {
		log.Fatalf("Failed to copy object to buffer: %v", err)
	}

	log.Println("Buffer content:", buf.String())
}

Bir nesneyi yerel dosyaya indirme

Aşağıdaki kod bir nesneyi yerel dosyaya indirir:

package main

import (
	"io"
	"log"
	"os"

	"github.com/aliyun/aliyun-oss-go-sdk/oss"
)

func main() {
	// Obtain access credentials from environment variables. Before you run this sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are set.
	provider, err := oss.NewEnvironmentVariableCredentialsProvider()
	if err != nil {
		log.Fatalf("Failed to create credentials provider: %v", err)
	}

	// Create an OSSClient instance.
	// Set yourEndpoint to the Endpoint of the bucket. For example, for a bucket in the China (Hangzhou) region, set the Endpoint to https://oss-cn-hangzhou.aliyuncs.com. For other regions, set the Endpoint as needed.
	// Set yourRegion to the region where the bucket is located. For example, for a bucket in the China (Hangzhou) region, set the region to cn-hangzhou. For other regions, set the region as needed.
	clientOptions := []oss.ClientOption{oss.SetCredentialsProvider(&provider)}
	clientOptions = append(clientOptions, oss.Region("yourRegion"))
	// Set the signature version.
	clientOptions = append(clientOptions, oss.AuthVersion(oss.AuthV4))
	client, err := oss.New("yourEndpoint", "", "", clientOptions...)
	if err != nil {
		log.Fatalf("Failed to create OSS client: %v", err)
	}

	// Set yourBucketName to the name of the bucket.
	bucketName := "yourBucketName" // Replace this with the actual bucket name.
	bucket, err := client.Bucket(bucketName)
	if err != nil {
		log.Fatalf("Failed to get bucket: %v", err)
	}

	// Download the object to a local file.
	// Set yourObjectName to the full path of the object. The full path does not include the bucket name.
	objectName := "yourObjectName" // Replace this with the actual object path.
	body, err := bucket.GetObject(objectName)
	if err != nil {
		log.Fatalf("Failed to get object: %v", err)
	}
	defer body.Close()

	// Open or create a local file.
	localFilePath := "LocalFile" // Replace this with the actual local file path.
	fd, err := os.OpenFile(localFilePath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0660)
	if err != nil {
		log.Fatalf("Failed to open or create local file: %v", err)
	}
	defer fd.Close()

	// Copy the content of the OSS object to the local file.
	_, err = io.Copy(fd, body)
	if err != nil {
		log.Fatalf("Failed to copy object to local file: %v", err)
	}

	log.Println("File downloaded successfully to", localFilePath)
}

İlgili bilgiler

Tam akışlı indirme örnek kodu: GitHub örneği.
Akışlı indirme API referansı: GetObject.