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Object Storage Service:Determine whether an object exists

Last Updated:Oct 12, 2023

This topic describes how to determine whether an object exists.

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 Security Token Service (STS), see Create an OSSClient instance.

  • To determine whether an object exists, you must have the oss:GetObject permission. For more information, see Common examples of RAM policies.

Sample code

The following sample code provides an example on how to determine whether an object exists:

<?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;

// 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.  
$accessKeyId = getenv("OSS_ACCESS_KEY_ID"); 
$accessKeySecret = getenv("OSS_ACCESS_KEY_SECRET");
// In this example, the endpoint of the China (Hangzhou) region is used. Specify your actual endpoint. 
$endpoint = "http://oss-cn-hangzhou.aliyuncs.com";
$bucket= "<yourBucketName>";
$object = "<yourObjectName>";

try{
    $ossClient = new OssClient($accessKeyId, $accessKeySecret, $endpoint);

    $exist = $ossClient->doesObjectExist($bucket, $object);
} catch(OssException $e) {
    printf(__FUNCTION__ . ": FAILED\n");
    printf($e->getMessage() . "\n");
    return;
}
print(__FUNCTION__ . ": OK" . "\n");
var_dump($exist);