Findbugs Maven plugin - findbugs-exclude with multiple projects

Question

I've got a multiple project setup, using Maven and the Findbugs plugin. I need to exclude some files in one of the child projects, so I added it to findbugs-exclude.xml. That works when I build in the subproject.

My issue comes when I try to build at top level. Maven is not finding the findbugs-exclude.xml in the subproject. So it doesn't ignore my errors and fails because of them. I can put my findbugs-exclude.xml in the top level directory, and the exclusion works. But that's polluting the top level, and would not be looked upon favorably.

Is there a way to get the Maven plugin to use the findbugs-exclude.xml file from a subdirectory? Preferably with little to no change at the top level?

Answer 1

One solution for this is to create a seperate project which contains the findbugs-excludes.xml and then use the dependency plugin to unpack and place it locally where it's required something like this:

<profile>
    <id>static-analysis</id>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-dependency-plugin</artifactId>
                <executions>
                    <execution>
                        <id>unpack-findbugs</id>
                        <phase>process-resources</phase>
                        <goals>
                            <goal>unpack</goal>
                        </goals>
                        <configuration>
                            <artifactItems>
                                <artifactItem>
                                    <groupId>com.myproject</groupId>
                                    <artifactId>my-findbugs</artifactId>
                                    <version>0.1-SNAPSHOT</version>
                                    <type>jar</type>
                                    <overWrite>true</overWrite>
                                    <outputDirectory>src/main/findbugs/</outputDirectory>
                                </artifactItem>
                            </artifactItems>
                            <!-- other configurations here -->
                            <excludes>META-INF/</excludes>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>findbugs-maven-plugin</artifactId>
                <configuration>
                    <xmlOutput>true</xmlOutput>
                    <!-- Optional directory to put findbugs xdoc xml report -->
                    <xmlOutputDirectory>target/findbugs</xmlOutputDirectory>
                    <effort>Max</effort>
                    <threshold>Low</threshold>
                    <excludeFilterFile>src/main/findbugs/findbugs-excludes.xml</excludeFilterFile>
                </configuration>
                <executions>
                    <execution>
                        <id>findbugs-run</id>
                        <phase>compile</phase>
                        <goals>
                            <goal>check</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</profile>

With this approach you can then share this exclusion file across projects if required which could be a good or a bad thing depending on how you look at it :) Also, thinking about it, if you have a dedicated findbugs project you can create different flavours of exclusions using classifiers and the use a specific classifier depending on the context. It's not perfect but it works for me.

HTH, James