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  • is it possible to use reflection at compile-time? Commented Apr 16, 2020 at 11:17
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    @MohamedAouledIssa Do you mean something like reading the value of an annotation during compilation and e.g. validate it? That can't be done with regular Java reflection. But it can be done with an Annotation Processor which is run during compilation. The relevant Java APIs for this are javax.annotation.processing and javax.lang.model, which could be described as compile-time reflections Commented Apr 17, 2020 at 10:28
  • Right! I Have written a dozen of annotation processors in my career so it's something obvious and that's what it was designed for actually. My use case is pretty much specific. I have an android app that has multiple modules and i want to be able to write some code in a specific module, something not possible with annotation processors even when i specifically define the output dir. Any ideas how to solve this? Many thanks Commented Apr 17, 2020 at 10:57
  • @MohamedAouledIssa Generating additional code during compilation is generally supported by annotation processors. At least for regular Java - I don't know if Android annotation processing may have some limitations here. Annotation processors are not allowed to modify code, but if you need that it apparently can still be done: stackoverflow.com/q/13690272/897024 (again at least in Java, by modifying byte code. Android may works differently here but since there is Lombok for Android, I guess it is possible) Commented Apr 17, 2020 at 11:19
  • Android AP is the same as Java AP. nothing fancy to be honest but the problem is that i can't have my Annotation processor generate classes at a different location from the default one. I can do that if the output dir is in the same submodule but never in a different module. Annotation processor in module A will not be able to generate code in submodule B. I don't need to modify the code. I just need to output it somewhere else. Commented Apr 17, 2020 at 11:23