Hi 奥田 章桂美,
For Java Spring Boot applications, it only support Secret/Connection string as the only authentication method. You may refer it in the same link you shared.
Refer the below tutorial that helps you to understand how to upload a file from your Spring Boot application to Blob Storage.
and Refer the below Github repository for further examples.
https://github.com/Azure-Samples/azure-spring-boot-samples/tree/main/storage
Hope this helps