What does HackerNews think of javapoet?
A Java API for generating .java source files.
The canonical way to do such a thing is through the java annotation processing api [1] and using a tool like java poet [2]. Before you did that, you'd probably decide if you wanted to instead use bytecode generation with a library like bytebuddy [3]
But, assuming for some reason, you wanted to torture yourself and actually consume a java.in file and apply a regex, then you'd probably pull out the "maven-replacer-plugin" [4] and configure that for the task at hand. (or use your favorite templating language plugin. There's a million of them).
Though, to be fair, this really isn't something that comes up in regular java programming due to the nature of the ecosystem. Anything you'd want to codegen likely already has a library and anything you didn't would receive (legitimate) push back.
> And could you really say that this would be cleaner than the same thing done with cmake?
Probably not. But not really the main point. cmake becomes a problem when you want to do anything more complex than string replacement. Imagine, for example, if you did want to use a code generation library within a project. The strength of maven is a new team dev only needs maven. Further, if they need to update that library they only need to change that maven file.
What happens with cmake if you wanted to update a minimum dependency?
[1] https://www.baeldung.com/java-annotation-processing-builder