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 from 0 to 1,000, data from byte 0 to byte 1,000, 1,001 bytes in total, are returned. If the specified range is invalid, data of the whole object will be returned. Sample code is as follows:

// Create an instance of ObsClient.
var obsClient = new ObsClient({
    // Hard-coded or plaintext AK/SK are risky. For security purposes, encrypt your AK/SK and store them in the configuration file or environment variables. In this example, the AK/SK are stored in environment variables for identity authentication. Before running this example, configure environment variables AccessKeyID and SecretAccessKey.
    // The front-end code does not have the process environment variable, so you need to use a module bundler like webpack to define the process variable.
    // Obtain an AK/SK pair on the management console.
    access_key_id: process.env.AccessKeyID,
    secret_access_key: process.env.SecretAccessKey,
    server: 'https://your-endpoint'
});

obsClient.getObject({
       Bucket : 'bucketname',
       Key : 'objectname',
       // Specify the download range.
       Range : 'bytes=0-1000'
}, function (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); 
              }
       }
});

• Use the Range parameter to specify the download range in the format of "bytes=x-y."
• 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.