SpotBugs Maven Plugin exclude a directory

Question

I use SpotBugs Maven Plugin for a static analysis and I would like to exclude a directory from the inspection. Looking at the spotbugs:check goal documentation, it seems that it is not possible to configure the plugin is such a way. I also checked documentation for a SpotBugs filter file.

In Apache Maven PMD Plugin this can be done by using excludeRoots parameter:

<excludeRoots>
  <excludeRoot>target</excludeRoot>
</excludeRoots>

Is it possible to exclude a directory from SpotBugs inspection?

Goulette

It looks like SpotBugs approaches the issue from the opposite direction. You don't tell it what to ignore, you tell it what to look at: spotbugs.github.io/spotbugs-maven-plugin/… – Bedclothes

Answer 1

It is possible to exclude a directory from inspection with SpotBugs, though the approach is different to the one you described for PMD. It is a two step process:

1. First create an XML filter file specifying the criteria for the directory(s) to be excluded.

2. Then, in pom.xml refer to that that file using the optional <excludeFilterFile> setting. Unfortunately, the documentation for that setting is very brief.

As a simple example:

1. Create a filter file named ignore.xml containing the following which refers to a directory named mydir:

    <?xml version="1.0" encoding="UTF-8"?>
    <FindBugsFilter>
        <Match>
            <Source name="~mydir\..*"/>
        </Match>
    </FindBugsFilter>
   

   The documentation for the <Source> tag is here. See the section on Java element name matching for details on how to specify the name of the <Source>.

2. Then in pom.xml, in the specification for spotbugs-maven-plugin, include an <excludeFilterFile> tag so that mydir is ignored by SpotBugs:

    <configuration>
      <excludeFilterFile>ignore.xml</excludeFilterFile>
    </configuration>
   

Notes:

• There is also an <includeFilterFile> tag. See the section titled Specifying which bug filters to run in the usage documentation.

• As well as Source, SpotBugs provides several other ways to specify what code is to be included or excluded from checking. See the filter file documentation for the Package, Class, Method, Local, Field and Type tags.

• Place your <excludeFilterFile> in the root of your project.

Tagmeme

I tried the solution and it doesn't work. According to this SpotBugs ticket SourceFilter does not work with the full file path. – Goulette

@Goulette Try Package instead of Source. It works. – Cathouse

@Cathouse I had mentioned Package in my answer, but how does that help the OP? Their question is asking how to exclude a specific directory, not a package. – Tagmeme

@Goulette It looks like the implementation of open issue Add management for source filter using full source path (if available). #903 may be needed to resolve this. – Tagmeme

@Tagmeme Application class loader in JVM (the default one) searches for classes from given package in the corresponding directory structure. i.e class com.example.app.Class typically (in practice almost always) is placed in com/example/app directory. And vice versa, classes located in com/example/app directory typically have com.example.app package. So, effectively, excluding a package is usually the same as excluding directory. Of course, there are rare cases when we write or use custom ClassLoaders, but as far as I can see, most JVM applications use default class loading mechanism. – Cathouse

where would you place that ignore.xml? – Henigman

@Henigman and others, I just placed the include/exclude.xml files in the root of the Eclipse project, picked them up fine. – Cornwallis

@Cornwallis Thanks for that feedback - I just updated my answer accordingly. – Tagmeme