Aggregate findbugs report in Maven 3.0.5 - maven

Question

I am using multi-module Maven Project ( more than 10 modules ). I am trying to create a findbugs report of all module in single html page. Is there any way?
For creating individual report for each module, i am using the below
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>findbugs-maven-plugin</artifactId>
<version>3.0.0</version>
<configuration>
<!--
Enables analysis which takes more memory but finds more bugs.
If you run out of memory, changes the value of the effort element
to 'Low'.
-->
<effort>Max</effort>
<!-- Build doesn't fail if problems are found -->
<failOnError>false</failOnError>
<!-- Reports all bugs (other values are medium and max) -->
<threshold>Low</threshold>
<!-- Produces XML report -->
<xmlOutput>false</xmlOutput>
<skip>${skipFindbugs}</skip>
<!-- Configures the directory in which the XML report is created -->
<findbugsXmlOutputDirectory>${project.build.directory}/findbugs</findbugsXmlOutputDirectory>
</configuration>
<executions>
<!--
Ensures that FindBugs inspects source code when project is compiled.
-->
<execution>
<phase>compile</phase>
<goals>
<goal>findbugs</goal>
</goals>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>xml-maven-plugin</artifactId>
<version>1.0</version>
<configuration>
<transformationSets>
<transformationSet>
<!-- Configures the source directory of XML files. -->
<dir>${project.build.directory}/findbugs</dir>
<!-- Configures the directory in which the FindBugs report is written.-->
<outputDir>${project.build.directory}/findbugs</outputDir>
<!-- Selects the used stylesheet. -->
<!-- <stylesheet>fancy-hist.xsl</stylesheet> -->
<stylesheet>${project.parent.basedir}/default.xsl</stylesheet>
<!--<stylesheet>plain.xsl</stylesheet>-->
<!--<stylesheet>fancy.xsl</stylesheet>-->
<!--<stylesheet>summary.xsl</stylesheet>-->
<fileMappers>
<!-- Configures the file extension of the output files. -->
<fileMapper implementation="org.codehaus.plexus.components.io.filemappers.FileExtensionMapper">
<targetExtension>.html</targetExtension>
</fileMapper>
</fileMappers>
</transformationSet>
</transformationSets>
</configuration>
<executions>
<!-- Ensures that the XSLT transformation is run when the project is compiled. -->
<execution>
<phase>compile</phase>
<goals>
<goal>transform</goal>
</goals>
</execution>
</executions>
<dependencies>
<dependency>
<groupId>com.google.code.findbugs</groupId>
<artifactId>findbugs</artifactId>
<version>3.0.0</version>
</dependency>
</dependencies>
</plugin>

Answer 1

According to official documentation of the plugin (question n. 1), it is not possible.
However, here is the approach I used to achieve it:
Add an additional module to your existing multimodule project. This additional module will only be used for reporting
Configure the Buildhelper Maven Plugin to dynamically add the source code of the other modules to the reporting module. Note: you can do the same for resources, if required.
Configure the Findbugs plugin only on the reporting module
Add the other modules as dependencies of the reporting module, in order to have the Maven reactor build to build it only at the end.
If required: you don't want the reporting module to be part of your default build, create a profile in the aggregator/parent module which redefines the modules element and add the reporting module to it. As such, only when the profile will be activated (i.e. via command line, on demand) the reporting module will be added and the aggregated report will be created.
As an example, in the aggregator/parent module you can define as following:
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.sample</groupId>
<artifactId>findbugs-parent</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>pom</packaging>
<modules>
<module>findbugs-module1</module>
<module>findbugs-module2</module>
</modules>
<profiles>
<profile>
<id>findbugs-reporting</id>
<modules>
<module>findbugs-module1</module>
<module>findbugs-module2</module>
<module>findbugs-reporting</module>
</modules>
</profile>
</profiles>
</project>
Note: the findbugs-reporting module is only added in the findbugs-reporting profile. By default, the build will ignore it.
In the findbugs-reporting module, configure the POM using the configuration you posted (findbugs and XML maven plugin) and also add as following:
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>build-helper-maven-plugin</artifactId>
<version>1.9.1</version>
<executions>
<execution>
<id>add-source</id>
<phase>generate-sources</phase>
<goals>
<goal>add-source</goal>
</goals>
<configuration>
<sources>
<source>..\findbugs-module1\src\main\java</source>
<source>..\findbugs-module2\src\main\java</source>
</sources>
</configuration>
</execution>
</executions>
</plugin>
Note the added sources from other modules (change it according to your project).
Furthermore, we also need to add dependencies to the reporting module. It has to depend on other modules in order to be built at the end (and as such make sure to take the latest changes/sources from other modules). As an example:
<dependencies>
<dependency>
<groupId>com.sample</groupId>
<artifactId>findbugs-module1</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>
<dependency>
<groupId>com.sample</groupId>
<artifactId>findbugs-module2</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>
</dependencies>
Finally, you can invoke the reporting build as following from the aggregator/parent dir:
mvn clean install -Pfindbugs-reporting
As such, you will build the whole project and additionally activate the reporting module, which will dynamically include sources from other modules (as configured) and generate an aggregated report.
Depending on your needs, you can avoid the profile step (if you want it as part of your default build) or activate the profile by default (so that you can skip the reporting build deactivate it via -P!findbugs-reporting) or use the skipFindbugs property you already configured (and without the profile, in such a case).