Sample code required for Sharepoint service to upload the file to SP Online using java

[Rameshkumar-Mathiyazhgan]

Hello,

I am new to this API and i am trying to use this API to upload the file to Sharepoint online folders.
I cannot find any User guide to use this API as well. I cannot understand how to use this API with Java.
Kindly someone provide me the sample code to understand this Sharepoint service part in this API.

Thanks,
RameshKumar Mathiyazhgan