Solution Practice - Using the Photo Editing App
Updated at:2025-11-03
Interaction process
Upload images to BOS
The interaction process among the APP, APP server, and BOS when uploading images to BOS is as shown in the following figure:

- When the app uploads an image, it sends a request to the app server to retrieve the upload method.
- The app server uses STS to request the AK/SK for BOS access from the STS server, and the STS server provides the app server with temporary STS credentials, including an AK, SK, and Session Token.
- The app server returns the STS credentials and upload method parameters, which include the bucket name, endpoint, and other information.
- The app uploads the file to BOS using the provided information, and BOS responds with the upload result.
- The app can share the upload result with the app server as needed.
Download images from BOS
The interaction process among the APP, APP server, and BOS when downloading images from BOS is as shown in the following figure:

- When the app downloads an image, it sends a request to the app server to retrieve the download method.
- The app server uses STS to request the AK/SK for BOS access from the STS server, and the STS server provides the app server with temporary STS credentials, including an AK, SK, and Session Token.
- The app server sends the STS credentials and download method parameters to the app, including the bucket name, endpoint, and other relevant details.
- The APP, based on the returned information,
- The app downloads the file from BOS using the provided information, and BOS responds with the download result.
- The app can share the download result with the app server as needed.
Download scaled images from BOS
The interaction process among the APP, APP server, and BOS when downloading scaled images from BOS is as shown in the following figure:

The process for downloading scaled images from BOS is similar to that of downloading regular images from BOS. The only difference is that downloading scaled images requires including the image processing parameters configured in the app, such as width, height, rotation angle, etc.
