Définir les métadonnées d'un objet

Permet de définir les métadonnées d'un objet stocké dans un bucket Cloud Storage.

En savoir plus

Pour obtenir une documentation détaillée incluant cet exemple de code, consultez les articles suivants :

Afficher et modifier les métadonnées d'objet

Exemple de code

C++

Pour en savoir plus, consultez la documentation de référence de l'API Cloud Storage en langage C++.

Pour vous authentifier auprès de Cloud Storage, configurez le service Identifiants par défaut de l'application. Pour en savoir plus, consultez Configurer l'authentification pour un environnement de développement local.

namespace gcs = ::google::cloud::storage;
using ::google::cloud::StatusOr;
[](gcs::Client client, std::string const& bucket_name,
   std::string const& object_name, std::string const& key,
   std::string const& value) {
  StatusOr<gcs::ObjectMetadata> object_metadata =
      client.GetObjectMetadata(bucket_name, object_name);
  if (!object_metadata) throw std::move(object_metadata).status();

  gcs::ObjectMetadata desired = *object_metadata;
  desired.mutable_metadata().emplace(key, value);

  StatusOr<gcs::ObjectMetadata> updated =
      client.UpdateObject(bucket_name, object_name, desired,
                          gcs::Generation(object_metadata->generation()));

  if (!updated) throw std::move(updated).status();
  std::cout << "Object updated. The full metadata after the update is: "
            << *updated << "\n";
}

C#

Pour en savoir plus, consultez la documentation de référence de l'API Cloud Storage en langage C#.


using Google.Cloud.Storage.V1;
using System;
using System.Collections.Generic;

public class SetObjectMetadataSample
{
    public Google.Apis.Storage.v1.Data.Object SetObjectMetadata(
        string bucketName = "your-bucket-name",
        string objectName = "your-object-name",
        string key = "key-to-add",
        string value = "value-to-add")
    {
        var storage = StorageClient.Create();
        var file = storage.GetObject(bucketName, objectName);

        if (file.Metadata == null)
        {
            file.Metadata = new Dictionary<string, string>();
        }
        file.Metadata.Add(key, value);

        file = storage.UpdateObject(file);
        Console.WriteLine($"Updated custom metadata for object {objectName} in bucket {bucketName}");
        return file;
    }
}

Go

Pour en savoir plus, consultez la documentation de référence de l'API Cloud Storage en langage Go.

import (
	"context"
	"fmt"
	"io"
	"time"

	"cloud.google.com/go/storage"
)

// setMetadata sets an object's metadata.
func setMetadata(w io.Writer, bucket, object string) error {
	// bucket := "bucket-name"
	// object := "object-name"
	ctx := context.Background()
	client, err := storage.NewClient(ctx)
	if err != nil {
		return fmt.Errorf("storage.NewClient: %w", err)
	}
	defer client.Close()

	ctx, cancel := context.WithTimeout(ctx, time.Second*10)
	defer cancel()

	o := client.Bucket(bucket).Object(object)

	// Optional: set a metageneration-match precondition to avoid potential race
	// conditions and data corruptions. The request to update is aborted if the
	// object's metageneration does not match your precondition.
	attrs, err := o.Attrs(ctx)
	if err != nil {
		return fmt.Errorf("object.Attrs: %w", err)
	}
	o = o.If(storage.Conditions{MetagenerationMatch: attrs.Metageneration})

	// Update the object to set the metadata.
	objectAttrsToUpdate := storage.ObjectAttrsToUpdate{
		Metadata: map[string]string{
			"keyToAddOrUpdate": "value",
		},
	}
	if _, err := o.Update(ctx, objectAttrsToUpdate); err != nil {
		return fmt.Errorf("ObjectHandle(%q).Update: %w", object, err)
	}
	fmt.Fprintf(w, "Updated custom metadata for object %v in bucket %v.\n", object, bucket)
	return nil
}

Java

Pour en savoir plus, consultez la documentation de référence de l'API Cloud Storage en langage Java.


import com.google.cloud.storage.Blob;
import com.google.cloud.storage.BlobId;
import com.google.cloud.storage.Storage;
import com.google.cloud.storage.StorageOptions;
import java.util.HashMap;
import java.util.Map;

public class SetObjectMetadata {
  public static void setObjectMetadata(String projectId, String bucketName, String objectName) {
    // The ID of your GCP project
    // String projectId = "your-project-id";

    // The ID of your GCS bucket
    // String bucketName = "your-unique-bucket-name";

    // The ID of your GCS object
    // String objectName = "your-object-name";

    Storage storage = StorageOptions.newBuilder().setProjectId(projectId).build().getService();
    Map<String, String> newMetadata = new HashMap<>();
    newMetadata.put("keyToAddOrUpdate", "value");
    BlobId blobId = BlobId.of(bucketName, objectName);
    Blob blob = storage.get(blobId);
    if (blob == null) {
      System.out.println("The object " + objectName + " was not found in " + bucketName);
      return;
    }

    // Optional: set a generation-match precondition to avoid potential race
    // conditions and data corruptions. The request to upload returns a 412 error if
    // the object's generation number does not match your precondition.
    Storage.BlobTargetOption precondition = Storage.BlobTargetOption.generationMatch();

    // Does an upsert operation, if the key already exists it's replaced by the new value, otherwise
    // it's added.
    blob.toBuilder().setMetadata(newMetadata).build().update(precondition);

    System.out.println(
        "Updated custom metadata for object " + objectName + " in bucket " + bucketName);
  }
}

Node.js

Pour en savoir plus, consultez la documentation de référence de l'API Cloud Storage en langage Node.js.

// Imports the Google Cloud client library
const {Storage} = require('@google-cloud/storage');

// Creates a client
const storage = new Storage();

/**
 * TODO(developer): Uncomment the following lines before running the sample.
 */
// The ID of your GCS bucket
// const bucketName = 'your-unique-bucket-name';

// The ID of your GCS file
// const fileName = 'your-file-name';

async function setFileMetadata() {
  // Optional: set a meta-generation-match precondition to avoid potential race
  // conditions and data corruptions. The request to set metadata is aborted if the
  // object's metageneration number does not match your precondition.
  const options = {
    ifMetagenerationMatch: metagenerationMatchPrecondition,
  };

  // Set file metadata.
  const [metadata] = await storage
    .bucket(bucketName)
    .file(fileName)
    .setMetadata(
      {
        // Predefined metadata for server e.g. 'cacheControl', 'contentDisposition',
        // 'contentEncoding', 'contentLanguage', 'contentType'
        contentDisposition:
          'attachment; filename*=utf-8\'\'"anotherImage.jpg"',
        contentType: 'image/jpeg',

        // A note or actionable items for user e.g. uniqueId, object description,
        // or other useful information.
        metadata: {
          description: 'file description...',
          modified: '1900-01-01',
        },
      },
      options
    );

  console.log(
    'Updated metadata for object',
    fileName,
    'in bucket ',
    bucketName
  );
  console.log(metadata);
}

setFileMetadata().catch(console.error);

PHP

Pour en savoir plus, consultez la documentation de référence de l'API Cloud Storage en langage PHP.

use Google\Cloud\Storage\StorageClient;

/**
 * Set a metadata key and value on the specified object.
 *
 * @param string $bucketName The name of your Cloud Storage bucket.
 *        (e.g. 'my-bucket')
 * @param string $objectName The name of your Cloud Storage object.
 *        (e.g. 'my-object')
 */
function set_metadata(string $bucketName, string $objectName): void
{
    $storage = new StorageClient();
    $bucket = $storage->bucket($bucketName);
    $object = $bucket->object($objectName);
    $object->update([
        'metadata' => [
            'keyToAddOrUpdate' => 'value',
        ]
    ]);

    printf('Updated custom metadata for object %s in bucket %s', $objectName, $bucketName);
}

Python

Pour en savoir plus, consultez la documentation de référence de l'API Cloud Storage en langage Python.

from google.cloud import storage


def set_blob_metadata(bucket_name, blob_name):
    """Set a blob's metadata."""
    # bucket_name = 'your-bucket-name'
    # blob_name = 'your-object-name'

    storage_client = storage.Client()
    bucket = storage_client.bucket(bucket_name)
    blob = bucket.get_blob(blob_name)
    metageneration_match_precondition = None

    # Optional: set a metageneration-match precondition to avoid potential race
    # conditions and data corruptions. The request to patch is aborted if the
    # object's metageneration does not match your precondition.
    metageneration_match_precondition = blob.metageneration

    metadata = {'color': 'Red', 'name': 'Test'}
    blob.metadata = metadata
    blob.patch(if_metageneration_match=metageneration_match_precondition)

    print(f"The metadata for the blob {blob.name} is {blob.metadata}")

Ruby

Pour en savoir plus, consultez la documentation de référence de l'API Cloud Storage en langage Ruby.

def set_metadata bucket_name:, file_name:
  # The ID of your GCS bucket
  # bucket_name = "your-unique-bucket-name"

  # The ID of your GCS object
  # file_name = "your-file-name"

  require "google/cloud/storage"

  storage = Google::Cloud::Storage.new
  bucket  = storage.bucket bucket_name, skip_lookup: true
  file    = bucket.file file_name

  file.update do |file|
    # Fixed key file metadata
    file.content_type = "text/plain"

    # Custom file metadata
    file.metadata["your-metadata-key"] = "your-metadata-value"
  end

  puts "Metadata for #{file_name} has been updated."
end

Étapes suivantes

Pour rechercher et filtrer des exemples de code pour d'autres produits Google Cloud, consultez l'explorateur d'exemples Google Cloud.