Automatically check Java files for coding standard compliance

Question

I'm working in Java development. I have recently come into a situation where I have to comply to coding standards: member and method ordering, naming conventions, modifier sequence. I am thinking about methods to either automate checking for compliance, or generate some sort of mechanism that does the reordering.

We're developing with Eclipse, but the technology would be open. One way it might work is to generate an external builder tool and add this to the projects. The disadvantage would be that it would automagically apply to all files, which could run into problems with legacy code, blowing up the error count to a degree where it is no longer a sensible metric of compliance. Also, it makes code reviews much more difficult, which is not wanted.

Another way would be some kind of parser with only informative capabilities. We could run a process inside Jenkins, and that certainly would work, but that would also mean that the code had already passed a review, which is usually a little late for a code compliance check.

Are there suggested or even easy methods to integrate such functionality into either IDE, the source control system (Mercurial) or even Jenkins? How is this enforced elsewhere?

Solution 1

I would not recommend doing such changes automatically. Even though most of the checkstyle/pmd complies are valid, it happens to me that I need to ignore some of the warnings/errors. Moreover - there is only very small pool of such easy issues. Most of the notifications require more complex operations and probably couldn't be done without human interaction.

I'm using Sonar integration. It contains many external checkers like PMD, CPD, Checkstyle, Findbugs and can integrate with some other useful tools like Cobertura (test coverage statistics). Its almost trivial to bind Sonar build to Jenkins build and trying to avoid major/critical issues might be considered as a good approach.

In developer environment I use Eclipse integration with findbugs. There is also some point of integration with sonar but it requires either submitting the code to server or running server locally, which I personally don't like. However after few cycles of polishing the code after code review in Sonar you will notice that you (and other team members) stick to most of the rules and checking reports on daily basis is enough.

Solution 2

One solution is to use JCSC / checkstyle or other tools that are command line friendly. Integrate this with your build process. Individual developer runs this on his branch.

Most tools integrate well with Jenkins (via plugins), which can be used as dash board

Solution 3

Further to @Jayan's answer, Jenkins has a CheckStyle plugin that will display the results of each CheckStyle run and let you set the build status depending on how many violations are found. So your setup steps would be:

1. Set up your CheckStyle rules to fit your coding standards
2. Add a step to your Jenkins build that runs CheckStyle
3. Add a post build step to publish the CheckStyle results.