CPD / PMD between projects?

Question

Hi all,

I am rephrasing this question to make it a little more straightforward and easy to understand, hopefully.

I have roughly 30 components (internal) that go into a single web application. That means 30 different projects with their own separate POM. I use inheritance quite a bit in my POMs so one of the things they inherit is a PMD/CPD configuration to prevent code duplication.

Even though I have CPD/PMD running, it only detects duplicate code within the same project. I would like it to detect in any of my projects if there is code shared among the projects that can be refactored out. Moreover, I was looking for something that could (using the same concept/pattern) verify that no code is shared between other open source dependencies.

It would be CPD/PMD, except it would operate on the source jars. This task would consume a large amount of memory if you scan all projects and their dependencies for duplication. Right now, I would just like to apply that to internal projects. If it works, then it would be relatively easy/straightforward to scale that out.

Walter

Answer 1

It sounds like you want to find duplicate code anywhere in your 30 projects. I can't speak for PMD; I assume you tell it to make one giant project containing all the source files from the union of the projects. But yes, this would take a lot of RAM and CPU.

Another tool that does is the Java CloneDR. The CloneDR finds duplicate code whether it is exactly the same or close (e.g., a few edits) regardless of source code layout or intervening comments. It is pretty easy to set it up to process all the files in your set of projects.

Answer 2

I'm not sure I got everything but...

I'd create an aggregating module with all projects as dependencies, use the maven-dependency-plugin and it's unpack-dependencies mojo to get all dependencies sources jar (the mojo can take a classifier as parameter) and unpack-them (maybe in target/generated-sources/java, the maven build helper plugin may help here) and finally run pmd:cpd on the whole source base.

This may need some tweaking, I didn't test this at all.

Answer 3

Just run PMD:CPD as a stand-alone program. All it needs is a directory, and it will recurse. At least, it did for me. I moved all my source to one directory and ran the CPD gui from the batch file distributed with PMD-4.2.5 .