How do I get the package of a local variable declaration in PMD and XPath?

Question

My problem

I want to create a custom ruleset for PMD that finds all declared variables that use a specific package. And it should be a XPath ruleset, because that is easier to maintain for me.

What I have so far

I am able to find import statements and variables. I'm using this XPath to find the declarations:

//VariableDeclarator[../Type
                          /ReferenceType
                             /ClassOrInterfaceType
                                [@Image = 'ClassA']]

However, this is only matching the exact class, but I want to check if this class comes from package my.package and I don't know how to get that.

Any hints?

Answer 1

Been a while since I used PMD, and I'm going from memory here, but try preceding your XPath with:

//ClassOrInterfaceDeclaration[preceding::PackageDeclaration/Name/@Image = 'my.package']//VariableDeclarator[etc..

Basically, it looks for a related node in the XML that declares the appropriate package. Like I said, this is from rather old memory, but hopefully it should at least point you in the right direction.