Get file download URL

Updated at：2025-11-03

Get file download URL

Users can obtain the URL of a specified object through the following code:

                Cpp
                
                std::string generatePresignedUrl(Client& client, const std::string& bucketName, const std::string& objectKey, int expirationInSeconds) {
 //Specify the name of the bucket where the object that the user needs to obtain is located, the name of the object, and the valid duration of the URL
   return  client.generate_url(bucketName, objectKey, expirationInSeconds);
}

Description:

Before calling this function, users need to manually set the endpoint to the domain name of the corresponding region. Baidu AI Cloud currently supports multiple regions. Please refer to[Region Selection Guide](Reference/Region Selection Instructions/Region.md). Currently, the supported regions include "North China-Beijing," "South China-Guangzhou" and "East China-Suzhou." Beijing region: http://bj.bcebos.com, Guangzhou region: http://gz.bcebos.com, Suzhou region: http://su.bcebos.com.

expirationInSeconds is the specified URL validity period, calculated from the current time. It is an optional parameter, and the system default value is 1,800 seconds if not configured. To set a permanent non-expiration time, the ExpirationInSeconds parameter can be set to -1. You cannot set it to any other negative value.

If the file to be obtained is expected to be publicly readable, the corresponding URL link can be quickly concatenated and obtained through simple rules: http://$bucket.$region.bcebos.com/$object

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