Contribution to POI

Introduction

Disclaimer

Any information in here that might be perceived as legal information is informational only. We're not lawyers, so consult a legal professional if needed.

The Licensing

The POI project is OpenSource and developed/distributed under the Apache Software License. Unlike other licenses this license allows free open source development; however, it does not require you to release your source or use any particular license for your source. If you wish to contribute to POI (which you're very welcome and encouraged to do so) then you must agree to release the rights of your source to us under this license.

I just signed an NDA to get a spec from Microsoft and I'd like to contribute

In short, stay away, stay far far away. Implementing these file formats in POI is done strictly by using public information. Public information includes sources from other open source projects, books that state the purpose intended is for allowing implementation of the file format and do not require any non-disclosure agreement and just hard work. We are intent on keeping it legal, by contributing patches you agree to do the same.

If you've ever received information regarding the OLE 2 Compound Document Format under any type of exclusionary agreement from Microsoft, or (probably illegally) received such information from a person bound by such an agreement, you cannot participate in this project. (Sorry)

Those submitting patches that show insight into the file format may be asked to state explicitly that they are eligible or possibly sign an agreement.

I just want to get involved but don't know where to start

Read the rest of the website, understand what POI is and what it does, the project vision, etc.
Use POI a bit, look for gaps in the documentation and examples.
Join the mail lists and share your knowledge with others.
Get CVS and check out the POI source tree
Documentation is always the best place to start contributing, maybe you found that if the documentation just told you how to do X then it would make more sense, modify the documentation.
Get used to building POI, you'll be doing it a lot, be one with the build, know its targets, etc.
Write Unit Tests. Great way to understand POI. Look for classes that aren't tested, or aren't tested on a public/protected method level, start there.
(HSSF)Get the Excel 97 Developer's Kit - its out of print but its dirt cheap (seen copies for under $15 (US)) used on amazon. It explains the Excel file format.
Submit patches (see below) of your contributions, modifications.
Fill out new features, see Bug database for suggestions.

Submitting Patches

Create patches by getting the latest sources from CVS (the HEAD). Alter or add files as appropriate. Then, from the jakarta-poi directiory, type cvs diff -u > mypatch.patch. This will capture all of your changes in a patch file of the appropriate format. Next, if you've added any files, create an archive (tar.bz2 preferred as its the smallest) in a path-preserving archive format, relative to your jakarta-poi directory. (Note: If you use WinCVS, move to [Admin] -> [Command Line] Menu and type "cvs diff -u" at [Enter a cvs line command] input field ([Commandline Settings] Tab), while selecting the target directories or files, in order to create unified diffs. In other words, [Alt+A]+[Alt+C]+[Alt+C] and type "cvs diff -u".) You'll attach both files in the next step.

Patches are submitted via the Bug Database. Create a new bug, set the subject to [PATCH] followed by a brief description. Explain you patch and any special instructions and submit/save it. Next, go back to the bug, and create attachements for the patch files you created. Be sure to describe not only the files purpose, but its format. (Is that ZIP or a tgz or a bz2 or what?).

Make sure your patches include the @author tag on any files you've altered or created. Make sure you've documented your changes and altered the examples/etc to reflect them. Any new additions should have unit tests. Lastly, ensure that you've provided approriate javadoc. (see Coding Standards). Patches that are of low quality may be rejected or the contributer may be asked to bring them up to spec.