I'm trying to implement file download directly via Browser. Our company uses Protocol Buffer as data communication format. So how can I download the file once I open the web page?
I tried to user bytes and stream of Protocol Buffer. But the result is
{"result":{"data":"Cw4ODg4ODgsMCw4ODg4ODgsMTUwMCwwLDE1MDAsNDAwMDAsMTAwMDAsMzAwMDAKMDMvMTEvMjAxNSxVbmtub3duIEl0ZW0sUHJlIFJvbGwgVmlkZW8gKG1heCAwOjMwKSw2MDAwMCwzMTAwMCwyOTAwMCw1MDAwMCwyNDAwMCwyNjAwMCwyMC4wMCUsODQ0NCwwLDQwMDAsNDQ0NCw4OTAzODgsMCwwLDAsODg4ODg4LDAsODg4ODg4LDE1MDAsMCwxNTAwLDQwMDAwLDIxMDAwLDE5MDAwCg=="}}
Protobuf is good for structured communication but http provides the perfect protocol for downloading files. The right headers need to be set and the browser will download the file.
If you really have to use protobuf to transfer files, then you need to add some javascript that is parsing the protobuf first and then turns it into a file that can be downloaded. See How to create a dynamic file + link for download in Javascript? for reference.
So, send the message as bytes, add the javascript that parses the protobuf message to extract the bytes, and then create the file download like on the linked answer.