How to Upload and Download Files to AWS S3 with Spring Boot - AWS SDK v2 and Presigned URL Support
This article explains how to implement file upload and download from a Spring Boot application to AWS S3 using AWS SDK v2. It covers how to choose between the SDK and spring-cloud-aws 3.x, a Service implementation that handles MultipartFile, presigned URL generation, IAM role authentication, and an example least-privilege policy, all with copy-and-paste-ready sample code.