• Object Storage Service

obs
  1. Help Center
  2. Object Storage Service
  3. Developer Guide (Node.js SDK)
  4. Object Download
  5. Performing a Partial Download

Performing a Partial Download

When only partial data of an object is required, you can download data falling within a specific range. If the specified range is 0 to 1000, data at the 0th to the 1000th bytes, 1001 bytes in total, will be returned. If the specified range is invalid, data of the whole object will be returned. Sample code is as follows:

// Import the OBS library.
var ObsClient = require('./lib/obs');

// Create an instance of ObsClient.
var obsClient = new ObsClient({
    access_key_id: '*** Provide your Access Key ***',       
    secret_access_key: '*** Provide your Secret Key ***',       
    server : 'yourdomainname'
});

obsClient.getObject({
       Bucket : 'bucketname',
       Key : 'objectkey',
// Set the start position and end position for downloading.
       Range : 'bytes=0-1000'
}, (err, result) => {
       if(err){
              console.error('Error-->' + err);
       }else{
              console.log('Status-->' + result.CommonMsg.Status);
              if(result.CommonMsg.Status < 300 && result.InterfaceResult){
                   // Obtain the object content.
                   console.log('Object Content:'); 
                   console.log(result.InterfaceResult.Content.toString()); 
              }
       }
});
NOTE:
  • Use the Range parameter to specify the download range in the "bytes=x-y" format.
  • If the specified range is invalid (because the start or end position is set to a negative integer or the range is larger than the object length), data of the whole object will be returned.