Question

How to implement secure multi-part file uploads to Amazon S3 using pre-signed URLs in Mendix?

0

I'm working on a Mendix 9.24.34 project, utilizing the official Amazon S3 and AWS Authentication Connectors. Currently, basic file uploads are functional, but I need to implement support for large file uploads (100MB+), specifically using pre-signed URLs, ideally in conjunction with multi-part uploads, to mitigate load on the Mendix runtime.

asked 2025-08-07

Mouli Dharan

1 answers

Vomeshwari Badhe · Accepted Answer · 2025-08-07

Hi Mouli,

You can implement secure multi-part uploads to Amazon S3 in Mendix using a mix of:

Java Actions – to generate pre-signed URLs via AWS SDK (InitiateMultipartUpload, GeneratePresignedUrl, CompleteMultipartUpload).
Client-side JavaScript – to split files and upload parts via fetch or XMLHttpRequest.
Custom UI – built in Mendix with a file input and progress tracking.

Helpful Links

AWS Docs: https://docs.aws.amazon.com/AmazonS3/latest/userguide/mpuoverview.html
AWS Java SDK Example: https://docs.aws.amazon.com/AmazonS3/latest/userguide/PresignedUrlUploadObject.html
Mendix Forum (related post): https://community.mendix.com/link/space/aws/questions/138160

Uploading and copying objects using multipart upload in Amazon S3 - Amazon Simple Storage Service

Upload a single object as a set of parts independently using the multipart upload API.

Thank you