I'm not asking for an opinion here - just a fact: is there a plugin, tool, or technique that lets me write classes or at least method bodies directly in bytecode in Java in either Eclipse or IntelliJ, and what is it? I'm not looking for runtime codegen, I want this at compile time.
I found one here: https://plugins.jetbrains.com/plugin/8461-bytecode-editor but there is no download link and I have no idea how to build it (I tried, I really did). But it's basically everything I want.
In .NET I use the excellent IL Support plugin for this, but I haven't found a similar solution for Java.
There is a download link on that page but you don't need to download it directly so that doesn't matter. IntelliJ provides a plugin installer In Settings>Plugins. At the botttom of the Plugins page is a button to 'Browse repositories'