tencent cloud

Overview

This document provides an overview of the API and sample code for quickly checking whether an object exists in a bucket. The sample code actually calls the HEAD Object COS API and is a simplified version of the API.

In addition to checking whether an object exists, HEAD Object returns object metadata. To view the SDK API that contains the full functionality of HEAD Object, please see Querying Object Metadata.

Description

The API is used to check whether an object exists in a bucket, which can be implemented by encapsulating the cos.headObject method.

Sample request

function doesObjectExist() {
 cos.headObject({
   Bucket: 'examplebucket-1250000000', /* Your bucket name. Required. */
   Region: 'COS_REGION',  /* Bucket region, such as `ap-beijing`. Required. */
   Key: '1.jpg',  /* Object key stored in the bucket (such as `1.jpg` and `a/b/test.txt`). Required. */
 }, function(err, data) {
       if (data) {
         console.log('The object exists.');
       } else if (err.statusCode == 404) {
         console.log('The object does not exist.');
       } else if (err.statusCode == 403) {
           console.log ('no permission to read the object');
       }
   });
}

Parameter description

Callback function description

function(err, data) { ... }