Objects that are stored in Object Storage Service (OSS) consist of keys, data, and object metadata. Object metadata describes the object. Object metadata includes standard HTTP headers and user metadata. You can create custom HTTP request policies such as object cache policies and forced object download policies by configuring standard HTTP headers. You can configure user metadata for an object to identify the purposes or attributes of the object.
Usage notes
In this topic, the public endpoint of the China (Hangzhou) region is used. If you want to access OSS from other Alibaba Cloud services in the same region as OSS, use an internal endpoint. For more information about OSS regions and endpoints, see Regions, endpoints and open ports.
In this topic, an OSSClient instance is created by using an OSS endpoint. If you want to create an OSSClient instance by using custom domain names or Security Token Service (STS), see Create an OSSClient instance.
To configure object metadata, you must have the
oss:PutObjectpermission. For more information, see Attach a custom policy to a RAM user.
Sample code
The following sample code provides an example on how to configure object metadata when you upload an object.
Before you configure object metadata for the object that you want to upload, check whether the directory contains an existing object that has the same name as the object to upload to prevent accidental object overwrites. For more information, see When I upload an object to a bucket and set metadata for the object simultaneously, how do I prevent an existing object with the same name in the bucket from being overwritten?
<?php
if (is_file(__DIR__ . '/../autoload.php')) {
require_once __DIR__ . '/../autoload.php';
}
if (is_file(__DIR__ . '/../vendor/autoload.php')) {
require_once __DIR__ . '/../vendor/autoload.php';
}
use OSS\Credentials\EnvironmentVariableCredentialsProvider;
use OSS\OssClient;
use OSS\CoreOssException;
// Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured.
$provider = new EnvironmentVariableCredentialsProvider();
// Specify the endpoint of the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com.
$endpoint = "yourEndpoint";
// Specify the name of the bucket. Example: examplebucket.
$bucket= "examplebucket";
// Specify the full path of the object. Do not include the bucket name in the full path. Example: exampledir/exampleobject.txt.
$object = "exampledir/exampleobject.txt";
$content = file_get_contents(__FILE__);
$options = array(
OssClient::OSS_HEADERS => array(
'Expires' => '2012-10-01 08:00:00',
'Content-Disposition' => 'attachment; filename="xxxxxx"',
'x-oss-meta-self-define-title' => 'user define meta info',
));
try{
$config = array(
"provider" => $provider,
"endpoint" => $endpoint,
"signatureVersion" => OssClient::OSS_SIGNATURE_VERSION_V4,
"region"=> "cn-hangzhou"
);
$ossClient = new OssClient($config);
// Configure object metadata when you upload the object.
$ossClient->putObject($bucket, $object, $content, $options);
} catch(OssException $e) {
printf(__FUNCTION__ . ": FAILED\n");
printf($e->getMessage() . "\n");
return;
}
print(__FUNCTION__ . ": OK" . "\n");
References
FAQ
When I upload an object to a bucket and set metadata for the object simultaneously, how do I prevent an existing object with the same name in the bucket from being overwritten?
You can use one of the following methods to prevent objects with the same name in the bucket from being overwritten:
Enable versioning
If you enable versioning for the bucket, OSS retains the existing object with the same name as a previous version and stores the object that you upload as the current version. You can restore previous versions of an object at any time. For more information, see Enable versioning.
Include the x-oss-forbid-overwrite header in the upload request
You can include the x-oss-forbid-overwrite header in the upload request and set the header to true. If you upload an object that has the same name as an existing object in the destination directory, the upload fails and OSS returns the FileAlreadyExists error. For more information, see PutObject.