Triggering "auto import" in bulk

I am looking for a way to trigger "auto import" of unambiguous imports on all my files.

My Java classes code is generated from a modelling tool. Annotation are included, such as lombocks @Data

So the class code needs a line

import lombok.Data;

which the model cant geenrate.

So I have switched on auto import on unambiguous imports, but that only triggers when there is a change in the file. 

I found running e.g. FindBugs, on all the files helps as the auto import is triggered when the file is opened - saving having to press the space bar!

But I have dozens of files to open. 

Is there a way to trigger auto import in bulk?