[Q/A][Java 17 (dubbo 3.3 Triple)] Please advise on how to implement file upload and download

[brookqin]

Pre-check

• I am sure that all the content I provide is in English.

Apache Dubbo Component

Java Samples (apache/dubbo-samples)

Details

1. The documentation at tripe-rest-manual mentions support for Multipart parameter ParamType.Part. Could you please guide me on how to use this feature to upload files?

2. How can I provide file download functionality through a service api? Would you kindly advise on:

   • Required annotations or configurations
   • Recommended return types for handling file streams

Thank you for your assistance!

Code of Conduct

• I agree to follow this project's Code of Conduct

[AlbumenJ]

@oxsean PTAL

[oxsean]

You can use @param(type=ParamType.Part) byte[] to accept uploads
use

byte[] download(String name){
   ...
}

to download file,.
But currently dubbo doesn't support streaming uploads and downloads, so the content shouldn't be too large.
Please contact me if you have any questions, it would be good if you could contribute an example.

[brookqin]

Thanks @oxsean

This weekend I tried several ways to implement upload and download functions.

The download function could use return byte[] like you said or try to get the httpresponse by var response = (HttpResponse) RpcContext.getServiceContext().getResponse() then write file to outputStream;

When upload files the service method like void upload(...); seems only support PathVariable/Header param, Part or other type params will stop dubbo to decode http body, so files can only be retrieved from var request = (HttpRequest) RpcContext.getServiceContext().getRequest().

Is it appropriate to use response.outputStream() to implement large file downloads?