@minedesh LOL, I don't think those J2ME Midletts, or what were they called? Java had Applets (for Web pages, so not "fully and really applications" ), then Servlets for Web servers (and the idea was that Applets could talk to Servlets = but who wants to do server side programming with Java!? There's almost certainly Perl on server already, and for all the wrong reasons, people loved PHP, which was easy to install as well.
But then they created Java 2 Mobile Edition, and again those MIDP applic... Urr, programs, couldn't be called applications - because Applications are graphical, targeted for end users, they are tools, office suites and games; like say, a Calendar (with networking, syncs, contacts, etc.), or a browser. Which is exactly what phones were doing, and Java made it possible to download and install new ones, like you know... Real programs.
So for reasons I can only reluctantly wonder, they had to be called Midlets - what's that then, like between applet and application, or what?
But I might have digressed, maybe just a wee bit.
So back to the YouTube.
I don't think there has ever been a Java mobile application to stream videos from YouTube; but I might be wrong, but I have never seen a J2ME Web browser that could stream videos. But then, the only ones I've found were Opera Mini and UC Browser.
Even those were slow to load, and highly optimized, Opera Mini Java app used what's in modern Android Opera Mini "extreme savings mode", or something like that, and what is in the modern version the so called "normal" mode, was what you got only with Opera Mobile with early smartphones (e.g. later Nokia Communicators or Nokia N900 Linux smartphone). I believe that on my N900 it used to be able to play YouTube videos, but even with that YT has changed too much for it to work on those old un-updated browsers. Even N900's standalone "YouTube Viewer", which wasn't a browser, but an application that parsed the webpages for stuff like URL from which to load and play the video itself.
Now that kind of app might barely be possible to write for J2ME, provided that there's an API for streaming the data, then uncompressing and playing the video - with hardware decoding, because there's no way those Java phones had the power to do that in software; especially when that software is not machine code, but needed to be interpreted on fly as well. Then there's the question of memory - how much it can even cache in memory... And swapping is likely totally not a solution, because the read/write speeds weren't usable for fast swapping between RAM and "disk".
If you had space, the most realistic idea would probably be an app to download the video, and then watching it with video player app.
But that's just my rambling long-*** thoughts, that nobody wanted or will ever read this far, about the whole idea. Feel free to correct me, maybe I'm completely lost with my thoughts, and my digressings 😅
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