Well, the API in question (which I've used, and it was indeed an unpleasant experience) might not be solving something trivial, but it's certainly not well designed.
My all-time worse API is SetupAPI, which despite its name is how you get access to USB devices on Windows. It's . . . pretty miserable. Runner-up is the COM-based stuff that manages the Windows firewall, which is not well specified and has 'interesting' timing issues.
I have mercifully lost most of my memory of the Java stuff I was doing 15 years ago. That stuff made me hate life.
My award goes to Extended MAPI. It took me weeks of trial and error just to read and send email messages through an Exchange Server. I remember people were selling 3rd party wrappers for the API, because it was so horrible.
I used the Extended MAPI API for years ... I thought there was something wrong with me as I struggled through the insanity ... until I saw modern APIs.
My all-time worse API is SetupAPI, which despite its name is how you get access to USB devices on Windows. It's . . . pretty miserable. Runner-up is the COM-based stuff that manages the Windows firewall, which is not well specified and has 'interesting' timing issues.
I have mercifully lost most of my memory of the Java stuff I was doing 15 years ago. That stuff made me hate life.