Copyright Headers from the Git History

The other day Vincent Zurczak has blogged about Updating Copyright Mentions with Eclipse and his way of maintaining legal headers in software artifacts is very similar to what we've always done in CDO. We had the exact same header in all artifacts and we used search and replace once per year to update them all. For us that has several disadvantages:

1. Most importantly that means to modify files that have no other (real) changes in that year.
2. It was hard to find the files with missing legal headers.
3. It was hard (well, mostly because I wasn't smart enough) to have different copyright owners.

What I always envisioned was a tool that identifies files that could or should have legal headers, consults the Git history for these files and assembles a copyright line as follows:

Copyright (c) 2008, 2009, 2011-2013 Owner and others.

Yesterday I've finally finished this tool:

A simple Check Copyrights for missing copyrights ends with:

Copyrights missing: 0
Copyrights rewritten: 0
Files visited: 22722
Time needed: 5.73 seconds

If there are copyrights missing the tool produces a list of the paths and can optionally open them in editors. The Update Copyrights action takes approx. 35 minutes on the same working tree and results in files with beautiful legal headers that are totally in line with the Git history.

If you are interested in the code have a look at UpdateCopyrightsAction.java. There are just a few places that are CDO-specific and I would be happy to review your patches to make the tool more flexible.