tencent cloud


Checking Whether Objects Exist

Last updated: 2022-01-17 12:50:00


    This document provides an overview of APIs and SDK code samples related to checking whether an object exists.

    API Operation Description
    HEAD Object Querying object metadata Queries the metadata of an object.

    SDK API References

    For the parameters and method description of all the APIs in the SDK, see API Documentation.

    Checking Whether an Object Exists


    This API accepts the bucket name and object name parameters as input parameters and return a Boolean value. It is in fact the encapsulation of the HeadObject (querying object metadata) API. To get the detailed metadata of an object, use the API for querying object metadata.

    Sample code

    using COSXML.Model.Object;
    using COSXML.Auth;
    using System;
    using COSXML;
    namespace COSSnippet
       public class DoesObjectExistModel {
          private CosXml cosXml;
          DoesObjectExistModel() {
           CosXmlConfig config = new CosXmlConfig.Builder()
             .SetRegion("COS_REGION") // Set the default region. For abbreviations of COS regions, visit https://www.tencentcloud.com/document/product/436/6224?from_cn_redirect=1.
           string secretId = "SECRET_ID";   // SecretId of the TencentCloud API. For more information about how to obtain the API key, see https://console.tencentcloud.com/cam/capi.
           string secretKey = "SECRET_KEY"; // SecretKey of the TencentCloud API. For more information about how to obtain the API key, see https://console.tencentcloud.com/cam/capi.
           long durationSecond = 600;          // Validity period of the request signature in seconds
           QCloudCredentialProvider qCloudCredentialProvider = new DefaultQCloudCredentialProvider(secretId, 
             secretKey, durationSecond);
           this.cosXml = new CosXmlServer(config, qCloudCredentialProvider);
          /// Check whether an object exists
         public void DoesObjectExist()
             // Bucket name in the format of `BucketName-APPID`. You can get APPID by referring to https://console.tencentcloud.com/developer.
             string bucket = "examplebucket-1250000000";
             string key = "exampleobject"; // Object key
             DoesObjectExistRequest request = new DoesObjectExistRequest(bucket, key);
             // Execute the request
             bool exist = cosXml.DoesObjectExist(request);
             // Request succeeded
             Console.WriteLine("object exist state is: " + exist);
           catch (COSXML.CosException.CosClientException clientEx)
             // Request failed
             Console.WriteLine("CosClientException: " + clientEx);
           catch (COSXML.CosException.CosServerException serverEx)
             // Request failed
             Console.WriteLine("CosServerException: " + serverEx.GetInfo());
          // .cssg-methods-pragma
          static void Main(string[] args)
           DoesObjectExistModel m = new DoesObjectExistModel();
            /// Check whether an object exists
           // .cssg-methods-pragma

    For the complete sample, go to GitHub.

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