Object metadata includes HTTP headers and user metadata. This topic describes how to set metadata when you upload an object.
Usage notes
- In this topic, the public endpoint of the China (Hangzhou) region is used. If you want to access OSS by using other Alibaba Cloud services in the same region as OSS, use an internal endpoint For more information about the regions and endpoints supported by OSS, see Regions and endpoints.
- 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 STS, see Create an OSSClient instance.
- To set object metadata, you must have the
oss:PutObject
permission. For more information, see Attach a custom policy to a RAM user.
Sample code
The following sample code provides an example on how to set object metadata when you upload an object:
<?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\OssClient;
use OSS\Core\OssException;
// The AccessKey pair of an Alibaba Cloud account has permissions on all API operations. Using these credentials to perform operations in OSS is a high-risk operation. We recommend that you use a RAM user to call API operations or perform routine O&M. To create a RAM user, log on to the RAM console.
$accessKeyId = "yourAccessKeyId";
$accessKeySecret = "yourAccessKeySecret";
// 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{
$ossClient = new OssClient($accessKeyId, $accessKeySecret, $endpoint);
// Set 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 keeps the existing object with the same name as a previous version and stores the object that you upload as the current version. You can recover to a previous version 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, the upload fails and OSS returns the FileAlreadyExists error. For more information, see PutObject.