Apache Jena : Contributing

The project welcomes contributions, large and small, from anyone.

The mailing list for project-wide discussions is dev@jena.apache.org and all development work happens in public, using GitHub isues and that mailing list.

The processes described here are guidelines, rather than fixed requirements.

Contributions

Contributions can be made by:

  • Github pull requests (preferred)
  • Emailing a patch file to the developers list

Contributions should include:

  • Tests
  • Documentation as needed

Documentation is kept and published via a git repository:

https://github.com/apache/jena-site/

Workflow

Github issues

The project uses github issues to track work. Please create a github issue so that we can track a contribution.

Github issue:

https://github.com/apache/jena/issues

Github

It is useful to create a Gihhub issue use the issue number (e.g. GH-9999) in the pull request title. This activates the automated mirroring of discussions onto the project developers mailing list.

To make a contribution:

  • On github, fork https://github.com/apache/jena into you github account.
  • Create a branch in your fork for the contribution.
  • Make your changes. Include the Apache source header at the top of each file.
  • Generate a pull request via github. Further changes to your branch will automatically show up in the pull request

Discussion and Merging

A project committer will review the contribution and coordinate any project-wide discussion needed. Review and discussion of the pull request itself takes place on github.

The committer review guide:

https://jena.apache.org/getting_involved/reviewing_contributions.html

Patches

An alternative is to upload a patch/diff to JIRA.

Code

Code style is about making the code clear for the next person who looks at the code.

The project prefers code to be formatted in the common java style with sensible deviation for short forms.

The project does not enforce a particular style but asks for:

  • Kernighan and Ritchie style “Egyptian brackets” braces.
  • Spaces for indentation
  • No @author tags.
  • One statement per line
  • Indent level 4 for Java
  • Indent level 2 for XML

See, for illustration: https://google.github.io/styleguide/javaguide.html#s4-formatting

The codebase has a long history - not all of it follows this style.

The code should have no warnings, in particular, use @Override and types for generics, and don't declared checked exceptions that are not used. Use @SuppressWarnings("unused") as necessary.

Please don't mix reformatting and functional changes; it makes it harder to review.

Legal

When you contribute, you affirm that the contribution is your original work and that you license the work to the Apache Software Foundation. You agree to license the material under the terms and conditions of the Contributor's Agreement.

You, as an individual, must be entitled to make the contribution to the project. If the contribution is part of your employment, please arrange this before making the contribution.

For a large contribution, the project may ask for a specific Software Grant from the contributor.

If in doubt, or if you have any questions, ask on the dev@jena.apache.org mailing list. Legal issues are easier to deal with if done before contributing, rather than after.

The project cannot accept contributions with unclear ownership nor contributions containing work by other people without a clear agreement from those people.